Final California 2026 Integrated Report (303(d) List/305(b) Report)

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324371

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2020-01-25 and 2020-01-25

EnviroWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324371

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2020-01-25 and 2020-01-25

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158188, Copper

Region 1

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324322

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2020-01-26 and 2020-01-26

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324376

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, DelilaDDING-TOP: 3px; font-smooth: always">Smith River HU, Delilah Creek

LOE ID:

324322

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2020-01-26 and 2020-01-26

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324376

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2021-05-11 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324325

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2021-05-11 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2021-05-11 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324325

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2021-05-11 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324375

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Line of Evidence (LOE) for Decision ID 158188, Copper

Region 1

Smith River HU, Delilah Creek

LOE ID:

324375

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Copper.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved copper criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 9 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2020-01-25 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324367

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2020-01-25 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324367

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324363

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2020-01-26 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158188, Copper

Region 1

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324363

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2020-01-26 and 2021-05-11

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

133967

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Info00%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Smith River HU, Delilah Creek

LOE ID:

133967

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia, for Survival, Ceriodaphnia dubia, for Young/female. 0 of the 3 samples collected by SWAMP RWB1 Monitoring for Smith River HU, Delilah Creek exhibited acute toxicity. 0 of 0 samples showed chronic toxicity. The chronic toxicity test results could not be used with the confidence and degree of certainty required by the listing policy. The Toxicity Final Report (2013-2015) from the UC Davis Aquatic Health Program Laboratory stated that sample hardness and conductivity in the samples had some of the lowest values they have tested in the laboratory. They cautioned that hardness/conductivity interferences although not consistent, need to be considered. They speculate that the variability could be due to the event-based nature of the sampling, where water samples were collected during or directly after significant storm events. They stated that care should be used when interpreting data results. While they said including Low Conductivity Controls in initial screening tests can help elucidate conductivity interferences; in some cases the combination of low hardness/conductivity and a contaminant(s) appeared to be a major contributor to some of the observed impairment in the data set. In light of these confounding factors, it was concluded that the test species did not meet the test species acceptability criteria and the results from the chronic toxicity tests were therefore not considered in the listing decision.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analyses of species diversity, population density, growth anomalies, bioassays of appropriate duration, or other appropriate methods as specified by the Regional Water Board(NCRWQCB 2018).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 stations. Monitoring site(s): ( 103DE5776 )

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

120976

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

TOXICITY TESTING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 stations. Monitoring site(s): ( 103DE5776 )

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

120976

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia, for Survival, Ceriodaphnia dubia, for Young/female. 1 of the 3 samples collected by SWAMP RWB1 Monitoring for Smith River HU, Delilah Creek exhibited acute toxicity. 0 of 0 samples showed chronic toxicity. The chronic toxicity test results could not be used with the confidence and degree of certainty required by the listing policy. The Toxicity Final Report (2013-2015) from the UC Davis Aquatic Health Program Laboratory stated that sample hardness and conductivity in the samples had some of the lowest values they have tested in the laboratory. They cautioned that hardness/conductivity interferences although not consistent, need to be considered. They speculate that the variability could be due to the event-based nature of the sampling, where water samples were collected during or directly after significant storm events. They stated that care should be used when interpreting data results. While they said including Low Conductivity Controls in initial screening tests can help elucidate conductivity interferences; in some cases the combination of low hardness/conductivity and a contaminant(s) appeared to be a major contributor to some of the observed impairment in the data set. In light of these confounding factors, it was concluded that the test species did not meet the test species acceptability criteria and the results from the chronic toxicity tests were therefore not considered in the listing decision.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 stations. Monitoring site(s): ( 103DE5776 )

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

109158

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Copper.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

A sample may have multiple toxicity test results, but will only be counted once. A sample is defined as being collected on the same day, at the same location with the same lab sample ID (if provided). The following organisms and parameters were utilized for the toxicity tests: Ceriodaphnia dubia, for Survival, Ceriodaphnia dubia, for Young/female. 1 of the 3 samples collected by SWAMP RWB1 Monitoring for Smith River HU, Delilah Creek exhibited acute toxicity. 0 of 0 samples showed chronic toxicity. The chronic toxicity test results could not be used with the confidence and degree of certainty required by the listing policy. The Toxicity Final Report (2013-2015) from the UC Davis Aquatic Health Program Laboratory stated that sample hardness and conductivity in the samples had some of the lowest values they have tested in the laboratory. They cautioned that hardness/conductivity interferences although not consistent, need to be considered. They speculate that the variability could be due to the event-based nature of the sampling, where water samples were collected during or directly after significant storm events. They stated that care should be used when interpreting data results. While they said including Low Conductivity Controls in initial screening tests can help elucidate conductivity interferences; in some cases the combination of low hardness/conductivity and a contaminant(s) appeared to be a major contributor to some of the observed impairment in the data set. In light of these confounding factors, it was concluded that the test species did not meet the test species acceptability criteria and the results from the chronic toxicity tests were therefore not considered in the listing decision.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 stations. Monitoring site(s): ( 103DE5776 )

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24.

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

109158

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal">

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

115399

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Copper.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

113402

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

115399

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

113402

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality standard for Copper.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

115391

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality standard for Copper.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID:

324291

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

op" width="33%">Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality standard for Copper. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID: 115391 Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Cold Freshwater Habitat Number of Samples: 3 Number of Exceedances: 2 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality standard for Copper. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: California Toxics Rule (CTR) lists criterion continuous concentrations to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-11 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158188, Copper	Region 1
Smith River HU, Delilah Creek

LOE ID: 324291 Pollutant: Copper LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Copper. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The secondary maximum contaminant level listed in Table 64449-A copper is 1.0 mg/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158261	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 1, 2-trichloro-1, 2, 2-trifluoroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158261, 1, 1, 2-trichloro-1, 2, 2-trifluoroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327154

Pollutant:

1, 1, 2-trichloro-1, 2, 2-trifluoroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 1, 2-Trichloro-1, 2, 2-trifluoroethane incorporated by reference in the Water Quality Control Plan, North Coast Basin is 1.2 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158262	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 1-dichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158262, 1, 1-dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324588

Pollutant:

1, 1-dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 1-Dichloroethane incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.005 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158311	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 2-Dibromoethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158311, 1, 2-Dibromoethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324564

Pollutant:

1, 2-Dibromoethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibromoethane, 1,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for ethylene dibromide (EDB) incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.05 ug/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158263	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 3 -dichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158263, 1, 3 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324572

Pollutant:

1, 3 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-Dichlorobenzene criterion for the protection of human health from the consumption of water and organisms is 400 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158263, 1, 3 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324573

Pollutant:

1, 3 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-Dichlorobenzene criterion for the protection of human health from consumption of organisms only is 2,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158264	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 4 -dichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158264, 1, 4 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324580

Pollutant:

1, 4 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 4-Dichlorobenzene incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.005 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158264, 1, 4 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324582

Pollutant:

1, 4 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 4-Dichlorobenzene criterion for the protection of human health from consumption of organisms only is 2,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158251	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,1,2-Tetrachloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158251, 1,1,1,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327032

Pollutant:

1,1,1,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for Tetrachloroethane, 1,1,1,2- as a drinking water level with a one in a million cancer risk is 0.001 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158255	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,1-Trichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158255, 1,1,1-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327165

Pollutant:

1,1,1-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 1, 1-Trichloroethane incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.2 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158272	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,2,2-Tetrachloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158272, 1,1,2,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327038

Pollutant:

1,1,2,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2, 2-Tetrachloroethane criterion for the protection of human health from consumption of organisms only is 11 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158272, 1,1,2,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327037

Pollutant:

1,1,2,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Tetrachloroethane, 1,1,2,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2, 2-Tetrachloroethane criterion for the protection of human health from the consumption of water and organisms is 0.17 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158304	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,2-Trichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327166

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2-Trichloroethane criterion for the protection of human health from the consumption of water and organisms is 0.60 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327172

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria (Gold Book) for freshwater aquatic life protection, chronic Lowest Observed Effect Level is 9,400 ug/L.

Guideline Reference:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327174

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2-Trichloroethane criterion for the protection of human health from consumption of organisms only is 42 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158171	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1-Dichloroethylene (DCE)/ Vinylidene Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158171, 1,1-Dichloroethylene (DCE)/ Vinylidene Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324599

Pollutant:

1,1-Dichloroethylene (DCE)/ Vinylidene Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichloroethylene, 1,1-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1-Dichloroethylene criterion for the protection of human health from the consumption of water and organisms is 0.057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158171, 1,1-Dichloroethylene (DCE)/ Vinylidene Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324598

Pollutant:

1,1-Dichloroethylene (DCE)/ Vinylidene Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1-Dichloroethylene criterion for the protection of human health from consumption of organisms only is 3.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158287	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2,3-Trichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158287, 1,2,3-Trichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327185

Pollutant:

1,2,3-Trichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichloropropane, 1,2,3-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15, Division 4, Article 4, Section 64435 (Tables 2 and 3), and Section 64444.5 (Table 5), and listed in Table 3-2 of this Plan (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Basin Plan's 'Chemical Constituents' objective. The California Maximum Contaminant Level for trichloropropane, 1,2,3- is 0.000005 mg/L (California Code of Regulations, Title 22).

Guideline Reference:

California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158173	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2,4-Trichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158173, 1,2,4-Trichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327157

Pollutant:

1,2,4-Trichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichlorobenzene, 1,2,4-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA recommended criterion for 1,2,4-trichlorobenzene for the protection of human health from the consumption of organisms only is 0.076 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158173, 1,2,4-Trichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327160

Pollutant:

1,2,4-Trichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin: Waters designated for MUN shall not contain concentrations of chemical constituents in excess of the MCL specified in Title 22 of the California Code of Regulations. The maximum contaminant level listed in Table 64444-A for 1, 2, 4-Trichlorobenzene is 0.005 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158179	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2,4-Trimethylbenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158179, 1,2,4-Trimethylbenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327193

Pollutant:

1,2,4-Trimethylbenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Drinking water notification levels are published by the Division of Drinking Water and are for chemicals for which there is no drinking water MCL. If a notification level is exceeded, local government notification is required and customer notification is recommended. The criteria for 1,2,4-Trimethylbenzene is 0.33 mg/L.

Guideline Reference:

Drinking Water Notification and Response Levels: An Overview

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158187	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dibromo-3-chloropropane (DBCP)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158187, 1,2-Dibromo-3-chloropropane (DBCP)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324554

Pollutant:

1,2-Dibromo-3-chloropropane (DBCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibromo-3-Chloropropane, 1,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 2-Dibromo-3-Chloropropane(DBCP) incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.0002 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158190	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158190, 1,2-Dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324593

Pollutant:

1,2-Dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloroethane criterion for the protection of human health from consumption of organisms only is 99 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158190, 1,2-Dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324591

Pollutant:

1,2-Dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichloroethane, 1,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-dichloroethane criterion for the protection of human health from the consumption of water and organisms is 0.38 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158244	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloroethylene,-trans
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158244, 1,2-Dichloroethylene,-trans	Region 1
Smith River HU, Delilah Creek

LOE ID:

324605

Pollutant:

1,2-Dichloroethylene,-trans

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-trans-dichlorethylene criterion for the protection of human health from consumption of organisms only is 140,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158244, 1,2-Dichloroethylene,-trans	Region 1
Smith River HU, Delilah Creek

LOE ID:

324608

Pollutant:

1,2-Dichloroethylene,-trans

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Basin Plan's 'Chemical Constituents' objective. The CA Primary MCL for trans 1,2-Dichloroethylene is 10 ug/L

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158193	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158193, 1,2-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324614

Pollutant:

1,2-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloropropane criterion for the protection of human health from consumption of organisms only is 39 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158193, 1,2-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324615

Pollutant:

1,2-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloropropane criterion for the protection of human health from the consumption of water and organisms is 0.52 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158279	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3,5-Trimethylbenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158279, 1,3,5-Trimethylbenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327197

Pollutant:

1,3,5-Trimethylbenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Drinking Water Notification and Response Levels: An Overview

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158288	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3-Dichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158288, 1,3-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324617

Pollutant:

1,3-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 3-Dichloropropane incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.5 ug/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158201	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3-Dichloropropene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158201, 1,3-Dichloropropene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324625

Pollutant:

1,3-Dichloropropene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for 1, 3-Dichloropropene incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.5 ug/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158201, 1,3-Dichloropropene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324621

Pollutant:

1,3-Dichloropropene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-dichloropropylene criterion for the protection of human health from the consumption of organisms only is 1,700 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158207	Region 1
Smith River HU, Delilah Creek

Pollutant:	2,2'-Dichlorodiethyl ether
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158207, 2,2'-Dichlorodiethyl ether	Region 1
Smith River HU, Delilah Creek

LOE ID:

323804

Pollutant:

2,2'-Dichlorodiethyl ether

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bis(2-chloroethyl)ether. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bis(2-chloroethyl)ether criterion for the protection of human health from the consumption of water and organisms is 0.031 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158207, 2,2'-Dichlorodiethyl ether	Region 1
Smith River HU, Delilah Creek

LOE ID:

323806

Pollutant:

2,2'-Dichlorodiethyl ether

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bis(2-chloroethyl)ether. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bis(2-chloroethyl)ether criterion for the protection of human health from consumption of organisms only is 1.4 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158285	Region 1
Smith River HU, Delilah Creek

Pollutant:	2-Chlorotoluene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158285, 2-Chlorotoluene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324140

Pollutant:

2-Chlorotoluene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to o-chlorotoluene is a concentration of 100 ug/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158286	Region 1
Smith River HU, Delilah Creek

Pollutant:	4-Chlorotoluene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158286, 4-Chlorotoluene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324143

Pollutant:

4-Chlorotoluene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to p-chlorotoluene is a concentration of 100 ug/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158300	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acetone
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158300, Acetone	Region 1
Smith River HU, Delilah Creek

LOE ID:

322839

Pollutant:

Acetone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for acetone is 6300 ug/L.

Guideline Reference:

Compilation of Water Quality Goals

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158270	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acrolein
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322848

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrolein criterion for the protection of human health from the consumption of water and organisms is 320 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322841

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA recommended acrolein criterion for the protection of aquatic life in freshwater is 3 ug/L ( 4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322846

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The acrolein criterion for the protection of human health from consumption of organisms only is 780 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158274	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acrylonitrile
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158274, Acrylonitrile	Region 1
Smith River HU, Delilah Creek

LOE ID:

322849

Pollutant:

Acrylonitrile

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrylonitrile. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrylonitrile criterion for the protection of human health from the consumption of water and organisms is 0.059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158274, Acrylonitrile	Region 1
Smith River HU, Delilah Creek

LOE ID:

322850

Pollutant:

Acrylonitrile

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrylonitrile. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrylonitrile criterion for the protection of human health from consumption of organisms only is 0.66 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	158289	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 107311 has been replaced by LOE 348942, LOE 113321 has been replaced by LOE 348950, LOE 107313 has been replaced by LOE 348934, and LOE 107315 has been replaced by LOE 348949 due to a reassessment of data using the USEPA Aquatic Life Benchmark threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

107317

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

114896

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-10-01

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

107312

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348950

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348949

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Aldicarb.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348934

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348942

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

107314

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

322855

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldicarb. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

322861

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to aldicarb as a drinking water level is a concentration of 0.007 mg/L.

Guideline Reference:

2018 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .


DECISION ID	158291	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

114898

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin to protect aquatic life in freshwater as criterion maximum concentration is 3 ug/L . This established criteria was divided by 2 in order to better represent a CMC value as specified in footnote g of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

107320

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

105770

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

115066

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

106332

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

104214

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

322883

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The aldrin criterion maximum concentration (expressed as a 1-day average) to protect aquatic life in freshwater is 1.5 ug/L. The criterion of 3 ug/L provided in the California Toxics Rule is an instantaneous maximum concentration and was divided by 2 in order to better represent a criterion maximum concentration (CMC) value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule (2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

322875

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criterion for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

322870

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criterion for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158164	Region 1
Smith River HU, Delilah Creek

Pollutant:	Allethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158164, Allethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

323151

Pollutant:

Allethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Allethrin is the USEPA Aquatic Life Benchmark of 1.05 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	102623	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3 of the Listing Policy. Under section 3 a single line of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 102623, Aluminum	Region 1
Smith River HU, Delilah Creek

LOE ID:

119186

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 102623, Aluminum	Region 1
Smith River HU, Delilah Creek

LOE ID:

107331

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158296	Region 1
Smith River HU, Delilah Creek

Pollutant:	Ametryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

117135

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

113340

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

323256

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

323261

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for ametryn is the USEPA Aquatic Life Benchmark of 3.67 ug/L for nonvascular plants.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

107334

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

118075

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158261	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 1, 2-trichloro-1, 2, 2-trifluoroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158261, 1, 1, 2-trichloro-1, 2, 2-trifluoroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327154

Pollutant:

1, 1, 2-trichloro-1, 2, 2-trifluoroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .


DECISION ID	104122	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aminomethyl Phosphonic Acid (AMPA)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Three line(s) of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

114920

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

110313

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

107342

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158262	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 1-dichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158262, 1, 1-dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324588

Pollutant:

1, 1-dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158311	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 2-Dibromoethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158311, 1, 2-Dibromoethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324564

Pollutant:

1, 2-Dibromoethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .


DECISION ID	104698	Region 1
Smith River HU, Delilah Creek

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of four samples exceed the objective for COLD and zero of 6 samples exceed the objective for MUN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of four samples exceed the objective for COLD and zero of 6 samples exceed the objective for MUN and these samples sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

114917

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic su


DECISION ID	158263	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 3 -dichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158263, 1, 3 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324572

Pollutant:

1, 3 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-Dichlorobenzene criterion for the protection of human health from the consumption of water and organisms is 400 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158263, 1, 3 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324573

Pollutant:

1, 3 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-Dichlorobenzene criterion for the protection of human health from consumption of organisms only is 2,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Control Plan (Basin Plan) for the North Coast Region

bstances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board).

Objective/Criterion Reference:

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

113342

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the formula listed in the Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013 document.

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-10-01 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

107338

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

107336

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158264	Region 1
Smith River HU, Delilah Creek

Pollutant:	1, 4 -dichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158264, 1, 4 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324580

Pollutant:

1, 4 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158264, 1, 4 -dichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324582

Pollutant:

1, 4 -dichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 4-Dichlorobenzene criterion for the protection of human health from consumption of organisms only is 2,600 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	104132	Region 1
Smith River HU, Delilah Creek

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line(s) of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 104132, Anthracene	Region 1
Smith River HU, Delilah Creek

LOE ID:

121506

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Anthracene .

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Anthrazene from MacDonald et al., 2000a which states that the probable effect concentration for Anthrazene is 845 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158251	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,1,2-Tetrachloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158251, 1,1,1,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327032

Pollutant:

1,1,1,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for Tetrachloroethane, 1,1,1,2- as a drinking water level with a one in a million cancer risk is 0.001 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158255	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,1-Trichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158255, 1,1,1-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327165

Pollutant:

1,1,1-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	100825	Region 1
Smith River HU, Delilah Creek

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 100825, Arsenic	Region 1
Smith River HU, Delilah Creek

LOE ID:

107347

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100825, Arsenic	Region 1
Smith River HU, Delilah Creek

LOE ID:

107344

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158272	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,2,2-Tetrachloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158272, 1,1,2,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327038

Pollutant:

1,1,2,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2, 2-Tetrachloroethane criterion for the protection of human health from consumption of organisms only is 11 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158272, 1,1,2,2-Tetrachloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327037

Pollutant:

1,1,2,2-Tetrachloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Tetrachloroethane, 1,1,2,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2, 2-Tetrachloroethane criterion for the protection of human health from the consumption of water and organisms is 0.17 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158170	Region 1
Smith River HU, Delilah Creek

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

323717

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

323726

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a 'less-than' value (for example, <1,500) and may underestimate toxicity.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

107350

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat


DECISION ID	158304	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,1,2-Trichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327166

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2-Trichloroethane criterion for the protection of human health from the consumption of water and organisms is 0.60 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327172

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria (Gold Book) for freshwater aquatic life protection, chronic Lowest Observed Effect Level is 9,400 ug/L.

Guideline Reference:

Quality Criteria for Water 1986. United States Environmental Protection Agency. Office of Water. Regulations and Standards. Washington D.C. EPA 440/5-86-001.

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158304, 1,1,2-Trichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327174

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1, 2-Trichloroethane criterion for the protection of human health from consumption of organisms only is 42 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

tr> Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity." Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107348 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity." Guideline Reference:

DECISION ID

158171

Region 1

Smith River HU, Delilah Creek

Pollutant:	1,1-Dichloroethylene (DCE)/ Vinylidene Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158171, 1,1-Dichloroethylene (DCE)/ Vinylidene Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324599

Pollutant:

1,1-Dichloroethylene (DCE)/ Vinylidene Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichloroethylene, 1,1-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1-Dichloroethylene criterion for the protection of human health from the consumption of water and organisms is 0.057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158171, 1,1-Dichloroethylene (DCE)/ Vinylidene Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324598

Pollutant:

1,1-Dichloroethylene (DCE)/ Vinylidene Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 1-Dichloroethylene criterion for the protection of human health from consumption of organisms only is 3.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

/ref4508.xlsx" >OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 114934 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107351 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use:

DECISION ID

158287

Region 1

Smith River HU, Delilah Creek

Pollutant:	1,2,3-Trichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158287, 1,2,3-Trichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327185

Pollutant:

1,2,3-Trichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichloropropane, 1,2,3-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

California MCLs - Title 17 and Title 22 documents for 2019 - California Regulations Related to Drinking Water

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

t" valign="top" width="67%">Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107355 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-11 an


DECISION ID	158173	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2,4-Trichlorobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158173, 1,2,4-Trichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327157

Pollutant:

1,2,4-Trichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Trichlorobenzene, 1,2,4-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA recommended criterion for 1,2,4-trichlorobenzene for the protection of human health from the consumption of organisms only is 0.076 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158173, 1,2,4-Trichlorobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327160

Pollutant:

1,2,4-Trichlorobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158179	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2,4-Trimethylbenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158179, 1,2,4-Trimethylbenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327193

Pollutant:

1,2,4-Trimethylbenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

107353

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity."

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

105026

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Guideline Reference:

Drinking Water Notification and Response Levels: An Overview

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

gn="left" valign="top" width="67%">3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity." Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107349 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158187	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dibromo-3-chloropropane (DBCP)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158187, 1,2-Dibromo-3-chloropropane (DBCP)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324554

Pollutant:

1,2-Dibromo-3-chloropropane (DBCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibromo-3-Chloropropane, 1,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158190	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158190, 1,2-Dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324593

Pollutant:

1,2-Dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloroethane criterion for the protection of human health from consumption of organisms only is 99 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

DECISION ID

158209

Region 1

Smith River HU, Delilah Creek

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

LOE ID:

118928

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

%">Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158190, 1,2-Dichloroethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324591

Pollutant:

1,2-Dichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichloroethane, 1,2-. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-dichloroethane criterion for the protection of human health from the consumption of water and organisms is 0.38 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE2222). Temporal Representation: Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

LOE ID: 108269 Pollutant: Azinphos-methyl (Guthion) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

LOE ID: 323739 Pollutant: Azinphos-methyl (Guthion) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

LOE ID: 118931 Pollutant: Azinphos-methyl (Guthion) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158244	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloroethylene,-trans
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158244, 1,2-Dichloroethylene,-trans	Region 1
Smith River HU, Delilah Creek

LOE ID:

324605

Pollutant:

1,2-Dichloroethylene,-trans

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-trans-dichlorethylene criterion for the protection of human health from consumption of organisms only is 140,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158244, 1,2-Dichloroethylene,-trans	Region 1
Smith River HU, Delilah Creek

LOE ID:

324608

Pollutant:

1,2-Dichloroethylene,-trans

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

California Maximum Contaminant Levels (MCLs) apply to ambient waters under the Basin Plan's 'Chemical Constituents' objective. The CA Primary MCL for trans 1,2-Dichloroethylene is 10 ug/L

Guideline Reference:

California Code of Regulations, Title 22, Division 4, Chapter 15. Domestic Water Quality and Monitoring

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	101714	Region 1
Smith River HU, Delilah Creek

Pollutant:	Azoxystrobin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1a single line(s) of evidence are necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Zero of one samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101714, Azoxystrobin	Region 1
Smith River HU, Delilah Creek

LOE ID:

107357

Pollutant:

Azoxystrobin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158193	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,2-Dichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158193, 1,2-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324614

Pollutant:

1,2-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloropropane criterion for the protection of human health from consumption of organisms only is 39 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158193, 1,2-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324615

Pollutant:

1,2-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 2-Dichloropropane criterion for the protection of human health from the consumption of water and organisms is 0.52 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158279	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3,5-Trimethylbenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158279, 1,3,5-Trimethylbenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

327197

Pollutant:

1,3,5-Trimethylbenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Drinking Water Notification and Response Levels: An Overview

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158172	Region 1
Smith River HU, Delilah Creek

Pollutant:	Benzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158172, Benzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323760

Pollutant:

Benzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Benzene incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.001 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158172, Benzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323763

Pollutant:

Benzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Benzene criterion for the protection of human health from consumption of organisms only is 71 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158288	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3-Dichloropropane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158288, 1,3-Dichloropropane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324617

Pollutant:

1,3-Dichloropropane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	105102	Region 1
Smith River HU, Delilah Creek

Pollutant:	Benzo(a)anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105102, Benzo(a)anthracene	Region 1
Smith River HU, Delilah Creek

LOE ID:

122028

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Benz[a]anthrazene from MacDonald et al., 2000a which states that the probable effect concentration for Benz[a]anthrazene is 1050 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	105103	Region 1
Smith River HU, Delilah Creek

Pollutant:	Benzo(a)pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105103, Benzo(a)pyrene	Region 1
Smith River HU, Delilah Creek

LOE ID:

122048

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Benzo[a]pyrene from MacDonald et al., 2000a which states that the probable effect concentration for Benzo[a]pyrene is 1450 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158201	Region 1
Smith River HU, Delilah Creek

Pollutant:	1,3-Dichloropropene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158201, 1,3-Dichloropropene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324625

Pollutant:

1,3-Dichloropropene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158201, 1,3-Dichloropropene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324621

Pollutant:

1,3-Dichloropropene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 1, 3-dichloropropylene criterion for the protection of human health from the consumption of organisms only is 1,700 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158265	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 113364 has been replaced by LOE 349099 and LOE 107358 has been replaced by LOE 349083 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

323802

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

DECISION ID

158207

Region 1

Smith River HU, Delilah Creek

Pollutant:	2,2'-Dichlorodiethyl ether
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158207, 2,2'-Dichlorodiethyl ether	Region 1
Smith River HU, Delilah Creek

LOE ID:

323804

Pollutant:

2,2'-Dichlorodiethyl ether

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bis(2-chloroethyl)ether. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bis(2-chloroethyl)ether criterion for the protection of human health from the consumption of water and organisms is 0.031 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158207, 2,2'-Dichlorodiethyl ether	Region 1
Smith River HU, Delilah Creek

LOE ID:

323806

Pollutant:

2,2'-Dichlorodiethyl ether

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bis(2-chloroethyl)ether. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bis(2-chloroethyl)ether criterion for the protection of human health from consumption of organisms only is 1.4 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158285	Region 1
Smith River HU, Delilah Creek

Pollutant:	2-Chlorotoluene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158285, 2-Chlorotoluene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324140

Pollutant:

2-Chlorotoluene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to o-chlorotoluene is a concentration of 100 ug/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

eft" valign="top" width="33%">Evaluation Guideline: The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used. Guideline Reference: Water Quality Criteria Report for Bifenthrin Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 121614 Pollutant: Bifenthrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Bifenthrin . Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007). Guideline Reference: Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5 Guideline Reference: Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396. Spatial Representation: Data were collected from 1 station(s). Station Code(s): 103DE5776. Temporal Representation: Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

DECISION ID

158286

Region 1

Smith River HU, Delilah Creek

Pollutant:	4-Chlorotoluene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158286, 4-Chlorotoluene	Region 1
Smith River HU, Delilah Creek

LOE ID:

324143

Pollutant:

4-Chlorotoluene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to p-chlorotoluene is a concentration of 100 ug/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 349083 Pollutant: Bifenthrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used. Guideline Reference: Water Quality Criteria Report for Bifenthrin Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2015-03-11 and 2015-06-24 Environmental Conditions: QAPP Information: Generic SWAMP QAPrP QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 349073 Pollutant: Bifenthrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used. Guideline Reference: Water Quality Criteria Report for Bifenthrin Spatial Representation: The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road). Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Generic SWAMP QAPrP QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 349099 Pollutant: Bifenthrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used. Guideline Reference: Water Quality Criteria Report for Bifenthrin Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Generic SWAMP QAPrP QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158300	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acetone
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158300, Acetone	Region 1
Smith River HU, Delilah Creek

LOE ID:

322839

Pollutant:

Acetone

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA IRIS reference dose (RfD) as a drinking water level, the drinking water health advisory level for acetone is 6300 ug/L.

Guideline Reference:

Compilation of Water Quality Goals

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	102996	Region 1
Smith River HU, Delilah Creek

Pollutant:	Boscalid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None samples exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 102996, Boscalid	Region 1
Smith River HU, Delilah Creek

LOE ID:

115484

Pollutant:

Boscalid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Boscalid is the USEPA Aquatic Life Benchmark of 116 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158270	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acrolein
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322848

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrolein criterion for the protection of human health from the consumption of water and organisms is 320 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322841

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA recommended acrolein criterion for the protection of aquatic life in freshwater is 3 ug/L ( 4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158270, Acrolein	Region 1
Smith River HU, Delilah Creek

LOE ID:

322846

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The acrolein criterion for the protection of human health from consumption of organisms only is 780 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158254	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromacil
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158254, Bromacil	Region 1
Smith River HU, Delilah Creek

LOE ID:

323818

Pollutant:

Bromacil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Bromacil as a drinking water level is a concentration of 0.07 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158254, Bromacil	Region 1
Smith River HU, Delilah Creek

LOE ID:

323816

Pollutant:

Bromacil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Bromacil is the USEPA Aquatic Life Benchmark of 6.8 ug/L for a nonvascular plant (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158283	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158283, Bromobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323820

Pollutant:

Bromobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health AdvisoryNAexposure limit for life-time exposure to Bromobenzen is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158274	Region 1
Smith River HU, Delilah Creek

Pollutant:	Acrylonitrile
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158274, Acrylonitrile	Region 1
Smith River HU, Delilah Creek

LOE ID:

322849

Pollutant:

Acrylonitrile

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrylonitrile. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrylonitrile criterion for the protection of human health from the consumption of water and organisms is 0.059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158274, Acrylonitrile	Region 1
Smith River HU, Delilah Creek

LOE ID:

322850

Pollutant:

Acrylonitrile

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrylonitrile. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Acrylonitrile criterion for the protection of human health from consumption of organisms only is 0.66 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158284	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromochloromethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158284, Bromochloromethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

323824

Pollutant:

Bromochloromethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to Bromochloromethane is a concentration of 0.09 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	158289	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aldicarb
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 107311 has been replaced by LOE 348942, LOE 113321 has been replaced by LOE 348950, LOE 107313 has been replaced by LOE 348934, and LOE 107315 has been replaced by LOE 348949 due to a reassessment of data using the USEPA Aquatic Life Benchmark threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

107317

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

DECISION ID

158174

Region 1

Smith River HU, Delilah Creek

Pollutant:	Bromoform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158174, Bromoform	Region 1
Smith River HU, Delilah Creek

LOE ID:

323832

Pollutant:

Bromoform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bromoform criterion for the protection of human health from consumption of organisms only is 360 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158174, Bromoform	Region 1
Smith River HU, Delilah Creek

LOE ID:

323836

Pollutant:

Bromoform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bromoform criterion for the protection of human health from the consumption of water and organisms is 4.3 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

> Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID: 114896 Pollutant: Aldicarb LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Aldicarb. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-10-01 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID: 107312 Pollutant: Aldicarb LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number


DECISION ID	101814	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101814, Cadmium	Region 1
Smith River HU, Delilah Creek

LOE ID:

107366

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101814, Cadmium	Region 1
Smith River HU, Delilah Creek

LOE ID:

115488

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for cadmium 0.005 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Aldicarb. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID: 348950 Pollutant: Aldicarb LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Aldicarb. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic). Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Generic SWAMP QAPrP

DECISION ID

158175

Region 1

Smith River HU, Delilah Creek

Pollutant:	Carbaryl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

109119

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348949

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348934

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-10-01

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107372

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107375

Pollutan33%">Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

348942

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

109121

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (BasinING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Line of Evidence (LOE) for Decision ID 158289, Aldicarb

Region 1

Smith River HU, Delilah Creek

LOE ID:

107314

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for aldicarb incorporated by reference in the Water Quality Control Plan, North Coast Basin is 3 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

322855

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldicarb. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for aldicarb is the USEPA Aquatic Life Benchmark of 0.46 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158289, Aldicarb	Region 1
Smith River HU, Delilah Creek

LOE ID:

322861

Pollutant:

Aldicarb

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to aldicarb as a drinking water level is a concentration of 0.007 mg/L.

Guideline Reference:

2018 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-10-01 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107373 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbaryl. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107377 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbaryl. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 323934 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Carbaryl. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference:

DECISION ID

158291

Region 1

Smith River HU, Delilah Creek

Pollutant:	Aldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

114898

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

107320

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

105770

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107371

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Smith River HU, Delilah Creek

Line of Evidence (LOE) for Decision ID 158175, Carbaryl

Region 1

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

115066

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

LOE ID:

107370

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

323930

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

tr> Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 106332 Pollutant: Aldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 104214 Pollutant: Aldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 322883 Pollutant: Aldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING

DECISION ID

158176

Region 1

Smith River HU, Delilah Creek

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

323939

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Carbofuran. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Cagn="top" width="33%">Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

322875

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criterion for aldrin to protect of human health from the consumption of water and organisms is 0.00013 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158291, Aldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

322870

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Aldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criterion for aldrin criteria for the protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

rbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic). Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID: 323941 Pollutant: Carbofuran LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Carbofuran. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID: 109125 Pollutant: Carbofuran LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Mu


DECISION ID	158164	Region 1
Smith River HU, Delilah Creek

Pollutant:	Allethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158164, Allethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

323151

Pollutant:

Allethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Allethrin is the USEPA Aquatic Life Benchmark of 1.05 ug/L for an invertebrate (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

nicipal & Domestic Supply Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Carbofuran. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-10-01 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID: 107381 Pollutant: Carbofuran LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbofuran. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID: 107379 Pollutant: Carbofuran LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbofuran. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID: 107380 Pollutant: Carbofuran LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbofuran. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158177	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbon Disulfide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158177, Carbon Disulfide	Region 1
Smith River HU, Delilah Creek

LOE ID:

323952

Pollutant:

Carbon Disulfide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Drinking water notification levels are published by the Division of Drinking Water. Notification levels are for chemicals for which there is no drinking water MCL. If a notification level is exceeded, local government notification is required and customer notification is recommended. The notification level for Carbon Disulfide is 0.160 mg/L.

Guideline Reference:

Drinking Water Notification Levels and Response Levels

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	102623	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aluminum
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3 of the Listing Policy. Under section 3 a single line of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 102623, Aluminum	Region 1
Smith River HU, Delilah Creek

LOE ID:

119186

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 102623, Aluminum	Region 1
Smith River HU, Delilah Creek

LOE ID:

107331

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158296	Region 1
Smith River HU, Delilah Creek

Pollutant:	Ametryn
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID:

117135

Pollutant:

Ametryn

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L

Guideline Reference:

DECISION ID

158178

Region 1

Smith River HU, Delilah Creek

Pollutant:	Carbon Tetrachloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158178, Carbon Tetrachloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

323956

Pollutant:

Carbon Tetrachloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The carbon tetrachloride criterion for the protection of human health from consumption of organisms only is 4.4 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158178, Carbon Tetrachloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

323953

Pollutant:

Carbon Tetrachloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Carbon Tetrachloride. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The carbon tetrachloride criterion for the protection of human health from the consumption of water and organisms is 0.25 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

oards.ca.gov/water_issues/programs/tmdl/records/state_board/2012/ref4281.pdf" >2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID: 113340 Pollutant: Ametryn LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Ametryn. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID: 323256 Pollutant: Ametryn LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ametryn. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for lifetime exposure to ametryn as a drinking water level is a concentration of 0.06 mg/L Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID: 323261 Pollutant: Ametryn LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Ametryn. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for ametryn is the USEPA Aquatic Life Benchmark of 3.67 ug/L for nonvascular plants. Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID: 107334 Pollutant: Ametryn LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Ametryn. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-11 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158296, Ametryn	Region 1
Smith River HU, Delilah Creek

LOE ID: 118075 Pollutant: Ametryn LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Ametryn. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for lifetime exposure to Ametryn as a drinking water level is a concentration of 0.06 mg/L Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	103105	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbophenothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None samples exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

109129

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

107383

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

107384

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	104122	Region 1
Smith River HU, Delilah Creek

Pollutant:	Aminomethyl Phosphonic Acid (AMPA)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Three line(s) of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

114920

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

110313

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 104122, Aminomethyl Phosphonic Acid (AMPA)	Region 1
Smith River HU, Delilah Creek

LOE ID:

107342

Pollutant:

Aminomethyl Phosphonic Acid (AMPA)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for AMPA is the USEPA Aquatic Life Benchmark of 249500 ug/L for a fish (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158180	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327111

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327114

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

114635

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:


DECISION ID	104698	Region 1
Smith River HU, Delilah Creek

Pollutant:	Ammonia
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. Zero of four samples exceed the objective for COLD and zero of 6 samples exceed the objective for MUN. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of four samples exceed the objective for COLD and zero of 6 samples exceed the objective for MUN and these samples sizes are insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

bstances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life (North Coast Regional Water Quality Control Board).

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

114917

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic suWater

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

102647

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

113342

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-10-01 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

107338

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Ammonia as a drinking water level is a concentration of 30 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 104698, Ammonia	Region 1
Smith River HU, Delilah Creek

LOE ID:

107336

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Aquatic Life Ambient Water Quality Criteria for Ammonia - Freshwater 2013

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

122002

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chlordane from MacDonald et al., 2000a which states that the probable effect concentration for Chlordane is 17.6 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

113359

Pollutant:

Chlordane

LOE Subgroup:

DECISION ID

104132

Region 1

Smith River HU, Delilah Creek

Pollutant:	Anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line(s) of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 104132, Anthracene	Region 1
Smith River HU, Delilah Creek

LOE ID:

121506

Pollutant:

Anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Anthrazene from MacDonald et al., 2000a which states that the probable effect concentration for Anthrazene is 845 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

h="67%">Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Total Chlordanes. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The Chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000) Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID: 102585 Pollutant: Chlordane LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Total Chlordanes. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID: 327104 Pollutant: Chlordane LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: The chlordane criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	100825	Region 1
Smith River HU, Delilah Creek

Pollutant:	Arsenic
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Four lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 100825, Arsenic	Region 1
Smith River HU, Delilah Creek

LOE ID:

107347

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for arsenic is 0.010 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 100825, Arsenic	Region 1
Smith River HU, Delilah Creek

LOE ID:

107344

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater for dissolved arsenic is 150 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158181	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

109131

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324061

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2020-01-25 and 2021-10-25

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

324020

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

Temporal Representation:

The samples were collected between the dates of 2020-01-26 and 2021-10-25

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

107387

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158170	Region 1
Smith River HU, Delilah Creek

Pollutant:	Atrazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

323717

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for atrazine is 1 ug/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

323726

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

107350

Pollutant:

Atrazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat


DECISION ID	158182	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorobenzene (mono)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158182, Chlorobenzene (mono)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324111

Pollutant:

Chlorobenzene (mono)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for monochlorobenzene incorporated by reference in the Water Quality Control Plan, North Coast Basin is 70 ug/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158182, Chlorobenzene (mono)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324110

Pollutant:

Chlorobenzene (mono)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlorobenzene criterion for the protection of human health from consumption of organisms only is 21,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

DECISION ID

158183

Region 1

Smith River HU, Delilah Creek

Pollutant:	Chlorodibromomethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158183, Chlorodibromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324560

Pollutant:

Chlorodibromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlorodibromomethane criterion for the protection of human health from consumption of organisms only is 34 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158183, Chlorodibromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324558

Pollutant:

Chlorodibromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibromochloromethane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlorodibromomethane criterion for the protection of human health from the consumption of water and organisms is 0.41 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107351 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use:

DECISION ID

158184

Region 1

Smith River HU, Delilah Creek

Pollutant:	Chloroform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158184, Chloroform	Region 1
Smith River HU, Delilah Creek

LOE ID:

324114

Pollutant:

Chloroform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloroform criteria for the protection of human health from consumption of organisms only is 2000 ug/L (National Recommended Water Quality Criteria).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158184, Chloroform	Region 1
Smith River HU, Delilah Creek

LOE ID:

324118

Pollutant:

Chloroform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA National Recommended Water Quality Criterion for chloroform for the protection of human health from consumption of water and organisms is 60 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek


DECISION ID	158168	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpropham
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158168, Chlorpropham	Region 1
Smith River HU, Delilah Creek

LOE ID:

324146

Pollutant:

Chlorpropham

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA expected safe lifetime exposure limit in drinking water for Chlorpropham, calculated using the IRIS Reference Dose, is 1200 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.2 mg/kg/day as the reference dose.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

d 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 107353 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity." Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-11 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 105026 Pollutant: Atrazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Atrazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Atrazine is the USEPA Aquatic Life Benchmark of < 1 ug/L for a nonvascular plant (acute). The benchmark was derived from a \less-than\" value (for example, <1,500) and may underestimate toxicity." Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158170, Atrazine	Region 1
Smith River HU, Delilah Creek


DECISION ID	158185	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324156

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administra


DECISION ID	158209	Region 1
Smith River HU, Delilah Creek

Pollutant:	Azinphos-methyl (Guthion)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

118928

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

tive Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.

2012 Edition of the Drinking Water Standards and Health Advisories

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Data was collected from 1 station(s) (Station Code(s) 103DE2222).

Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

108269

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

323739

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 158209, Azinphos-methyl (Guthion)	Region 1
Smith River HU, Delilah Creek

118931

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The National Recommended Water Quality Criteria for Azinphos Methyl (Guthion) for the protection of freshwater aquatic life is a maximum of 0.01 ug/l.

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	101714	Region 1
Smith River HU, Delilah Creek

Pollutant:	Azoxystrobin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1a single line(s) of evidence are necessary to assess listing status. One lines of evidence are available in the administrative record to assess this pollutant. Zero of one samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101714, Azoxystrobin	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for Azoxystrobin is the USEPA Aquatic Life Benchmark of 44 ug/L for an invertebrate (chronic).

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

https://www.waterboards.ca.gov/water_issues/programs/tmdl/records/region_1/2018/ref4527.pdf" >Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

109137

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1


DECISION ID	158172	Region 1
Smith River HU, Delilah Creek

Pollutant:	Benzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158172, Benzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323760

Pollutant:

Benzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Benzene incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.001 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158172, Benzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323763

Pollutant:

Benzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Benzene criterion for the protection of human health from consumption of organisms only is 71 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

T: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Smith River HU, Delilah Creek

LOE ID: 104929 Pollutant: Chlorpyrifos LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000). Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID: 324162 Pollutant: Chlorpyrifos LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chlorpyrifos. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data:

DECISION ID

105102

Region 1

Smith River HU, Delilah Creek

Pollutant:	Benzo(a)anthracene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105102, Benzo(a)anthracene	Region 1
Smith River HU, Delilah Creek

LOE ID:

122028

Pollutant:

Benzo(a)anthracene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Benz[a]anthrazene from MacDonald et al., 2000a which states that the probable effect concentration for Benz[a]anthrazene is 1050 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

gn="top" width="67%">SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water health advisory for chlorpyrifos is 2 ug/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID: 112488 Pollutant: Chlorpyrifos LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000). Guideline Reference: Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE2222). Temporal Representation: Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID: 107392 Pollutant: Chlorpyrifos LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Chlorpyrifos. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	105103	Region 1
Smith River HU, Delilah Creek

Pollutant:	Benzo(a)pyrene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105103, Benzo(a)pyrene	Region 1
Smith River HU, Delilah Creek

LOE ID:

122048

Pollutant:

Benzo(a)pyrene

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Benzo[a]pyrene from MacDonald et al., 2000a which states that the probable effect concentration for Benzo[a]pyrene is 1450 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	168240	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpyrifos, methyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107390

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

LOE ID:

109134

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107389

Pollutant:

Chlorpyrifos, methyl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158265	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bifenthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 113364 has been replaced by LOE 349099 and LOE 107358 has been replaced by LOE 349083 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

323802

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Bifenthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

DECISION ID

101562

Region 1

Smith River HU, Delilah Creek

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None samples exceed the objectives.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101562, Chromium	Region 1
Smith River HU, Delilah Creek

LOE ID:

107395

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101562, Chromium	Region 1
Smith River HU, Delilah Creek

LOE ID:

115895

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for chromium 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	105110	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105110, Chrysene (C1-C4)	Region 1
Smith River HU, Delilah Creek

LOE ID:

121780

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chrysene from MacDonald et al., 2000a which states that the probable effect concentration for Chrysene is 1290 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	168241	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cinerin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 107398 has been replaced by LOE 349150, LOE 109145 has been replaced by LOE 349149, LOE 116111 has been replaced by LOE 349115, and LOE 116111 has been replaced by LOE 349157 due to a reassessment of data using the USEPA Aquatic Life Benchmark threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349157

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L eft" valign="top" width="33%">Evaluation Guideline:

The chronic criterion for bifenthrin is 0.1 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of bifenthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Bifenthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

121614

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for bifenthrin is the median lethal concentration (LC50) of 0.43 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.43 ug/g is the geometric mean of LC50 values for bifenthrin from Amweg et al. (2005) and Amweg and Weston (2007).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349149

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349150

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349115

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek

Line of Evidence (LOE) for Decision ID 158265, Bifenthrin	Region 1
Smith River HU, Delilah Creek


DECISION ID	102996	Region 1
Smith River HU, Delilah Creek

Pollutant:	Boscalid
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None samples exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 102996, Boscalid	Region 1
Smith River HU, Delilah Creek

LOE ID:

115484

Pollutant:

Boscalid

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Boscalid is the USEPA Aquatic Life Benchmark of 116 ug/L for a fish (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158317	Region 1
Smith River HU, Delilah Creek

Pollutant:	Coumaphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324390

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

115453

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

117810

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

104169

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE2222).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158189	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cumene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158189, Cumene	Region 1
Smith River HU, Delilah Creek

LOE ID:

325109

Pollutant:

Cumene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA expected safe lifetime exposure limit in drinking water for Isopropylbenzene, calculated using the IRIS Reference Dose, is 0.7 mg/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.1 mg/kg/day as the reference dose.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158254	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromacil
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158254, Bromacil	Region 1
Smith River HU, Delilah Creek

LOE ID:

323818

Pollutant:

Bromacil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for lifetime exposure to Bromacil as a drinking water level is a concentration of 0.07 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158254, Bromacil	Region 1
Smith River HU, Delilah Creek

LOE ID:

323816

Pollutant:

Bromacil

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Bromacil is the USEPA Aquatic Life Benchmark of 6.8 ug/L for a nonvascular plant (acute).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158273	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cyanazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

324407

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life EC50 for Cyanazine is 4.8 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

115402

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

113414

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

115403

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

DECISION ID

158283

Region 1

Smith River HU, Delilah Creek

Pollutant:	Bromobenzene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158283, Bromobenzene	Region 1
Smith River HU, Delilah Creek

LOE ID:

323820

Pollutant:

Bromobenzene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health AdvisoryNAexposure limit for life-time exposure to Bromobenzen is a concentration of 0.06 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158284	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromochloromethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158284, Bromochloromethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

323824

Pollutant:

Bromochloromethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure to Bromochloromethane is a concentration of 0.09 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

r> Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 115405 Pollutant: Cyanazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 2 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality standard for Cyanazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-03-11 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 324400 Pollutant: Cyanazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Cyanazine. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water lifetime health advisory for cyanazine is 1 ug/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158174	Region 1
Smith River HU, Delilah Creek

Pollutant:	Bromoform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158174, Bromoform	Region 1
Smith River HU, Delilah Creek

LOE ID:

323832

Pollutant:

Bromoform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bromoform criterion for the protection of human health from consumption of organisms only is 360 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158174, Bromoform	Region 1
Smith River HU, Delilah Creek

LOE ID:

323836

Pollutant:

Bromoform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The bromoform criterion for the protection of human health from the consumption of water and organisms is 4.3 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	158305	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 116907 has been replaced by LOE 349208 and LOE 111271 has been replaced by LOE 349219 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349206

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The chronic criterion for cyfluthrin is 0.2 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cyfluthrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349219

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349208

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

324414

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

121962

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cyfluthrin is the median lethal concentration (LC50) of 1.1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.1 ug/g is the geometric mean of LC50 values for cyfluthrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	101814	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cadmium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101814, Cadmium	Region 1
Smith River HU, Delilah Creek

LOE ID:

107366

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101814, Cadmium	Region 1
Smith River HU, Delilah Creek

LOE ID:

115488

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for cadmium 0.005 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158307	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 110271 has been replaced by LOE 349925 and LOE 112955 has been replaced by LOE 349911 due to a reassessment of data using the UC Davis Aquatic Life Criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

349944

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The chronic criterion for lambda-cyhalothrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of lambda-cyhalothrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

349911

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda

DECISION ID	158175	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbaryl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

109119

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Region 1

Smith River HU, Delilah Creek

LOE ID:

349925

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

121542

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for lambda-cyhalothrin is the median lethal concentration (LC50) of 0.44 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.44 ug/g is the geometric mean of LC50 values for lambda-cyhalothrin from Amweg et al. (2005).

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

325115

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

://www.waterboards.ca.gov/water_issues/programs/tmdl/records/state_board/2016/ref4321.pdf" >National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-10-01 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107372 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbaryl. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE2222) Temporal Representation: The samples were collected between the dates of 2015-03-23 and 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107375 Pollutan


DECISION ID	158266	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 104322 has been replaced by LOE 349290 and LOE 108782 has been replaced by LOE 349289 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349290

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

109121

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin>

Evaluation Guideline:

The chronic criterion for cypermethrin is 0.3 ng/L (expressed as a 4-day average). If the freely dissolved concentrations of cypermethrin were reported or could be calculated then these values were used for this assessment. In the absence of freely dissolved concentrations, total concentrations were used.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349289

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

2012 Edition of the Drinking Water Standards and Health Advisories

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin

Region 1 &nbs Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-10-01

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107373

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

107377

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID:

323934

Pollutant:

Carbaryl

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Smith River HU, Delilah Creek

LOE ID:

324449

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349282

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

347619

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cypermethrin is the median lethal concentration (LC50) of 0.3 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.3 ug/g is the geometric mean of LC50 values for cypermethrin from Maund et al., (2002).

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

gov/water_issues/programs/tmdl/records/region_1/2018/ref4527.pdf" >Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 ug/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107371 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbaryl. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 107370 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Dissolved Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Carbaryl. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA national ambient water quality criterion for freshwater aquatic life criterion continuous concentration expressed as a 4 day average for carbaryl is 2.1 µg/L. Guideline Reference: National Recommended Water Quality Criteria. United States Environmental Protection Agency. Office of Water. Current as of 08/03/2016. Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158175, Carbaryl	Region 1
Smith River HU, Delilah Creek

LOE ID: 323930 Pollutant: Carbaryl LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Carbaryl. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA Health Advisory for carbaryl as a drinking water level with a one in a million cancer risk is 0.04 mg/L. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158176	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbofuran
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

323939

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Carbofuran. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Carbofuran is the USEPA Aquatic Life Benchmark of 0.75 ug/L for an invertibrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

323941

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

109125

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:


DECISION ID	161342	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104261

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115899

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115900

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-10-01

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

107381

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

107379

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158176, Carbofuran	Region 1
Smith River HU, Delilah Creek

LOE ID:

107380

Pollutant:

Carbofuran

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The California Maximum Contaminant Level for Carbofuran incorporated by reference in the Water Quality Control Plan, North Coast Basin is 0.018 mg/L (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158177	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbon Disulfide
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158177, Carbon Disulfide	Region 1
Smith River HU, Delilah Creek

LOE ID:

323952

Pollutant:

Carbon Disulfide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Drinking Water Notification Levels and Response Levels

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

lign="left" valign="top" width="33%">Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324460

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324457

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

122183

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Sum DDD from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDD is 28 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

112525

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158178	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbon Tetrachloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158178, Carbon Tetrachloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

323956

Pollutant:

Carbon Tetrachloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The carbon tetrachloride criterion for the protection of human health from consumption of organisms only is 4.4 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158178, Carbon Tetrachloride	Region 1
Smith River HU, Delilah Creek

LOE ID:

323953

Pollutant:

Carbon Tetrachloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Carbon Tetrachloride. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The carbon tetrachloride criterion for the protection of human health from the consumption of water and organisms is 0.25 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .


DECISION ID	161331	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115726

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

114387

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

122182<


DECISION ID	103105	Region 1
Smith River HU, Delilah Creek

Pollutant:	Carbophenothion
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Three lines of evidence are available in the administrative record to assess this pollutant. None samples exceed the objectives. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

109129

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

107383

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 103105, Carbophenothion	Region 1
Smith River HU, Delilah Creek

LOE ID:

107384

Pollutant:

Carbophenothion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

/td>

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324470

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324466

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115728

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

114400

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158180	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlordane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327111

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327114

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

114635

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

102647

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

122002

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chlordane from MacDonald et al., 2000a which states that the probable effect concentration for Chlordane is 17.6 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

113359

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlordane criterion continuous concentration expressed as a 4-day average for the protection of aquatic life in california waters is 0.0043 ug/L (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

102585

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from the consumption of water and organisms is 0.00057 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158180, Chlordane	Region 1
Smith River HU, Delilah Creek

LOE ID:

327104

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Total Chlordane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlordane criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	161320	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324478

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washingt


DECISION ID	158181	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chloride
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

Spatialon, D.C.: Environmental Protection Agency

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

324482

DDT (Dichlorodiphenyltrichloroethane)

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

324477

DDT (Dichlorodiphenyltrichloroethane)

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Water Quality Control Plan (Basin Plan) for the North Coast Region

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2020-01-25 and 2021-10-25

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

Benthic, Field, Habitat, Tissue, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Water Quality Control Plan (Basin Plan) for the North Coast Region

The samples were collected at 1 monitoring site: 103DE7500 (Delilah Creek at NW Westbrook Lane).

The samples were collected between the dates of 2020-01-26 and 2021-10-25

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 158181, Chloride	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

dth="33%">LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

105824

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

DECISION ID

158182

Region 1

Smith River HU, Delilah Creek

Pollutant:	Chlorobenzene (mono)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158182, Chlorobenzene (mono)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324111

Pollutant:

Chlorobenzene (mono)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158182, Chlorobenzene (mono)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324110

Pollutant:

Chlorobenzene (mono)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlorobenzene criterion for the protection of human health from consumption of organisms only is 21,000 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

tate_board/2003/ref476.pdf" >Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 115562 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 108693 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 115112 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 121643 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDT (Dichlorodiphenyltrichloroethane) . Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Sum DDT from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDT is 62.9 ug/kg. (dw = Dry Weight) Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31 Spatial Representation: Data were collected from 1 station(s). Station Code(s): 103DE5776. Temporal Representation: Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 115110 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 109175 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality:

DECISION ID

158183

Region 1

Smith River HU, Delilah Creek

Pollutant:	Chlorodibromomethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158183, Chlorodibromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324560

Pollutant:

Chlorodibromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chlorodibromomethane criterion for the protection of human health from consumption of organisms only is 34 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158183, Chlorodibromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324558

Pollutant:

Chlorodibromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dibromochloromethane. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The chlorodibromomethane criterion for the protection of human health from the consumption of water and organisms is 0.41 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

="left" valign="top" width="67%">Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for DDT (Dichlorodiphenyltrichloroethane). Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The Total DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 104217 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 115416 Pollutant: DDT (Dichlorodiphenyltrichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for DDT (Dichlorodiphenyltrichloroethane). Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The Total DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	158184	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chloroform
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158184, Chloroform	Region 1
Smith River HU, Delilah Creek

LOE ID:

324114

Pollutant:

Chloroform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Chloroform criteria for the protection of human health from consumption of organisms only is 2000 ug/L (National Recommended Water Quality Criteria).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158184, Chloroform	Region 1
Smith River HU, Delilah Creek

LOE ID:

324118

Pollutant:

Chloroform

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA National Recommended Water Quality Criterion for chloroform for the protection of human health from consumption of water and organisms is 60 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158168	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpropham
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158168, Chlorpropham	Region 1
Smith River HU, Delilah Creek

LOE ID:

324146

Pollutant:

Chlorpropham

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .


DECISION ID	168242	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

113423

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Lifetime Health advisory level for Dacthal is 0.07 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

115413

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Lifetime Health advisory level for Dacthal is 0.07 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

115411

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Dacthal is the USEPA Aquatic Life Benchmark of > 11000 ug/L for a nonvascular plant (acute) and vascular plant (acute). The benchmark was derived from a \greater-than\" value (for example, > 265,000) and may overestimate toxicity."

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

109170

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158185	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpyrifos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324156

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administra


DECISION ID	158306	Region 1
Smith River HU, Delilah Creek

Pollutant:	Deltamethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 109177 & 105890 has been replaced by LOE 349392 and LOE 115418 & 110894 has been replaced by LOE 349389 due to a reassessment of data using the USEPA Aquatic Life Benchmark threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158306, Deltamethrin	Region 1
Smith River HU, Delilah Creek

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158306, Deltamethrin	Region 1
Smith River HU, Delilah Creek

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158306, Deltamethrin	Region 1
Smith River HU, Delilah Creek

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Generic SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158306, Deltamethrin	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for deltamethrin is the median lethal concentration (LC50) of 0.79 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 0.79 ug/g is the geometric mean of LC50 values for deltamethrin (Amweg et al., 2005).

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Data were collected from 1 station(s). Station Code(s): 103DE5776 (Delilah Creek at Sarina Road).

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158306, Deltamethrin	Region 1
Smith River HU, Delilah Creek

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Deltamethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for deltamethrin is the USEPA Aquatic Life Benchmark of 0.000026 ug/L for an invertebrate (chronic).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

tive Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

115124

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

102518

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

121550

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for chlorpyrifos is the median lethal concentration (LC50) of 1.77 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Amweg and Weston, 2007).

Guideline Reference:

Whole-sediment toxicity identification evaluation tools for pyrethroid insecticides: I. piperonyl butoxide addition. Environ. Toxicol. Chem. 26:2389-2396.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

109137

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water health advisory for chlorpyrifos is 2 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1


DECISION ID	158309	Region 1
Smith River HU, Delilah Creek

Pollutant:	Demeton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158309, Demeton	Region 1
Smith River HU, Delilah Creek

LOE ID:

324516

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA expected safe lifetime exposure limit in drinking water for Demeton, calculated using the IRIS Reference Dose, is 0.3 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.0T: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Smith River HU, Delilah Creek

LOE ID:

104929

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorpyrifos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater criterion continuous concentration to protect aquatic organisms is 0.014 ug/L (Siepmann and Finlayson 2000).

Guideline Reference:

Water quality criteria for diazinon and chlorpyrifos. Administrative Report 00-3. Rancho Cordova, CA: Pesticide Investigations Unit, Office of Spills and Response. CA Department of Fish and Game

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324162

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158309, Demeton	Region 1
Smith River HU, Delilah Creek

LOE ID:

115421

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158309, Demeton	Region 1
Smith River HU, Delilah Creek

LOE ID:

115420

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158309, Demeton	Region 1
Smith River HU, Delilah Creek

LOE ID:

109180

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158309, Demeton	Region 1
Smith River HU, Delilah Creek

LOE ID:

324499

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to Demeton is 0.1 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek

Line of Evidence (LOE) for Decision ID 158185, Chlorpyrifos	Region 1
Smith River HU, Delilah Creek


DECISION ID	158192	Region 1
Smith River HU, Delilah Creek

Pollutant:	Diazinon
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

109193

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA reference dose (RfD) as a drinking water level, the drinking water health advisory level for Diazinon is 1.4 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

115423

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

115427

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA reference dose (RfD) as a drinking water level, the drinking water health advisory level for Diazinon is 1.4 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

324530

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA


DECISION ID	168240	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chlorpyrifos, methyl
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

The samples were collected at 1 monitoring site(s) (103DE5776)

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168240, Chlorpyrifos, methyl	Region 1
Smith River HU, Delilah Creek

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Water Quality Control Plan (Basin Plan) for the North Coast Region

The evaluation guideline for Chlorpyrifos Methyl is the USEPA Aquatic Life Benchmark of 0.085 ug/L for an invertebrate (acute).

The samples were collected at 1 monitoring site(s) (103DE2222)

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

115434

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA reference dose (RfD) as a drinking water level, the drinking water health advisory level for Diazinon is 1.4 µg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

115428

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

121655

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for diazinon is the median lethal concentration (LC50) of 11 ug/


DECISION ID	101562	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chromium
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. None samples exceed the objectives.. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to Section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 101562, Chromium	Region 1
Smith River HU, Delilah Creek

LOE ID:

107395

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 101562, Chromium	Region 1
Smith River HU, Delilah Creek

LOE ID:

115895

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of chemical constituents in excess of the limits specified in California Code of Regulations, Title 22, Chapter 15. The maximum contaminant level listed in Table 64431-A for chromium 0.05 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	105110	Region 1
Smith River HU, Delilah Creek

Pollutant:	Chrysene (C1-C4)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line(s) of evidence are necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. None of the samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. None of the one samples exceeded the objective and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 105110, Chrysene (C1-C4)	Region 1
Smith River HU, Delilah Creek

LOE ID:

121780

Pollutant:

Chrysene (C1-C4)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Chrysene from MacDonald et al., 2000a which states that the probable effect concentration for Chrysene is 1290 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 11 ug/g is the geometric mean of LC50 values for diazinon from Ding et al. (2011).

Guideline Reference:

Toxicity of Sediment-Associated Pesticides to Chironomus dilutus and Hyalella azteca. Arch. Environ. Contam. Toxicol. 61:83¿92.

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

109187

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.1 ug/L, expressed as a continuous concentration (Finlayson, 2004).

Guideline Reference:

Water quality for diazinon. Memorandum to J. Karkoski, Central Valley RWQCB. Rancho Cordova, CA: Pesticide Investigation Unit, CA Department of Fish and Game

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158192, Diazinon	Region 1
Smith River HU, Delilah Creek

LOE ID:

324542

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Based on USEPA reference dose (RfD) as a drinking water level, the drinking water health advisory level for Diazinon is 1 ug/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158194	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dichlorobromomethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158194, Dichlorobromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

323828

Pollutant:

Dichlorobromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dichlorobromomethane criteria for the protection of human health from consumption of organisms only is 46 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158194, Dichlorobromomethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

323826

Pollutant:

Dichlorobromomethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dichlorobromomethane criterion for the protection of human health from the consumption of water and organisms is 0.56 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	168241	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cinerin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 107398 has been replaced by LOE 349150, LOE 109145 has been replaced by LOE 349149, LOE 116111 has been replaced by LOE 349115, and LOE 116111 has been replaced by LOE 349157 due to a reassessment of data using the USEPA Aquatic Life Benchmark threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349157

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L


DECISION ID	158195	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dichlorodifluoromethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158195, Dichlorodifluoromethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

324585

Pollutant:

Dichlorodifluoromethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

USEPA's Drinking Water Health advisory for life-time exposure is a concentration for dichlorofluoromethane of 1 mg/L

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349149

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349150

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

lign="top" width="33%">Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 168241, Cinerin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349115

Pollutant:

Cinerin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for cinerin is the USEPA Aquatic Life Benchmark of 0.04 ug/L for freshwater invertebrates (chronic) and is the sum of cinerin-1 and cinerin-2.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158196	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dichloromethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158196, Dichloromethane	Region 1
Smith River HU, Delilah Creek

LOE ID:

325439

Pollutant:

Dichloromethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The dichloromethane (methylene chloride) criterion for the protection of human health from the consumption of water and organisms is 4.7 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1


DECISION ID	158317	Region 1
Smith River HU, Delilah Creek

Pollutant:	Coumaphos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324390

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumap


DECISION ID	158197	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dichlorvos
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158197, Dichlorvos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324626

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dichlorvos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for dichlorvos is the USEPA Aquatic Life Benchmark of 0.0058 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158197, Dichlorvos	Region 1
Smith River HU, Delilah Creek

LOE ID:

324628

Pollutant:

Dichlorvos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA IRIS one-in-a-million cancer risk estimate from oral exposure for dichlorvos is 0.1 ug/L.

Guideline Reference:

IRIS Database Calculations (summary)

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

hos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

115453

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

117810

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158317, Coumaphos	Region 1
Smith River HU, Delilah Creek

LOE ID:

104169

Pollutant:

Coumaphos

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Coumaphos. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Coumaphos is the USEPA Aquatic Life Benchmark of 0.0337 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE2222).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):


DECISION ID	158198	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dieldrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

102793

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

115871

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1


DECISION ID	158189	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cumene
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158189, Cumene	Region 1
Smith River HU, Delilah Creek

LOE ID:

325109

Pollutant:

Cumene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

style="background-color:#CCCCCC; PADDING-RIGHT: 2%; PADDING-LEFT: 0%; FONT-WEIGHT: bold; PADDING-BOTTOM: 3px; WIDTH: 100%; text-align: left; PADDING-TOP: 3px; font-smooth: always">Smith River HU, Delilah Creek

LOE ID: 115436 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Dieldrin. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect aquatic life in freshwater as criterion continuous concentration (expressed as a 4-day average) is 0.056 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2015-06-24 and 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 109196 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Dieldrin. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect aquatic life in freshwater as criterion continuous concentration (expressed as a 4-day average) is 0.056 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 121511 Pollutant: Dieldrin LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for Dieldrin . Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Dieldrin from MacDonald et al., 2000a which states that the probable effect concentration for Dieldrin is 61.8 ug/kg dw. (dw = Dry Weight) Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31 Spatial Representation: Data were collected from 1 station(s). Station Code(s): 103DE5776. Temporal Representation: Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 102344 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 324660 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Dieldrin. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect aquatic life in freshwater as criterion continuous concentration (expressed as a 4-day average) is 0.056 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 107461 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 324658 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protection of human health from consumption of organisms only is 0.00014 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158198, Dieldrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 324661 Pollutant: Dieldrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Dieldrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for dieldrin to protect human health from the consumption of water and organisms is 0.00014 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158271	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dimethoate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158271, Dimethoate	Region 1
Smith River HU, Delilah Creek

LOE ID:

324692

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The California Department of Health Services notification level for dimethoate is 1 ug/L.

Guideline Reference:

CDPH Archived Advisory Levels for Drinking Water. Archived Advisory Levels are currently considered Notification Levels.

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158271, Dimethoate	Region 1
Smith River HU, Delilah Creek

LOE ID:

109199

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158271, Dimethoate	Region 1
Smith River HU, Delilah Creek

LOE ID:

115440

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

DECISION ID

158273

Region 1

Smith River HU, Delilah Creek

Pollutant:	Cyanazine
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

324407

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Waters shall not contain toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. (Basin Plan, 2018)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the aquatic life EC50 for Cyanazine is 4.8 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

115402

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

113414

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158271, Dimethoate	Region 1
Smith River HU, Delilah Creek

LOE ID:

324681

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158271, Dimethoate	Region 1
Smith River HU, Delilah Creek

LOE ID:

115439

Pollutant:

Dimethoate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Dimethoate is the USEPA Aquatic Life Benchmark of 0.5 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

33%">Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Cyanazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID: 115403 Pollutant: Cyanazine LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality standard for Cyanazine. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

DECISION ID

158199

Region 1

Smith River HU, Delilah Creek

Pollutant:	Disulfoton
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID:

107302

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-03-11 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID:

117799

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for disulfoton is 0.7 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID:

115443

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for disulfoton is 0.7 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID:

106548

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, r>

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

115405

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158273, Cyanazine	Region 1
Smith River HU, Delilah Creek

LOE ID:

324400

Pollutant:

Cyanazine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for cyanazine is 1 ug/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .


DECISION ID	158305	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cyfluthrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 116907 has been replaced by LOE 349208 and LOE 111271 has been replaced by LOE 349219 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349206

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

plant, animal, or aquatic life. (Basin Plan).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic).

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID:

115442

Pollutant:

Disulfoton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA drinking water lifetime health advisory for disulfoton is 0.7 µg/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158199, Disulfoton

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349219

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349208

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

324414

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cyfluthrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Cyfluthrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158305, Cyfluthrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

121962

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

ign: right; PADDING-TOP: 3px; font-smooth: always">Region 1

Smith River HU, Delilah Creek

LOE ID: 107301 Pollutant: Disulfoton LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic). Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE2222). Temporal Representation: Date for this waterbody was collected over the date range 2015-03-23 to 2015-03-23 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID: 324705 Pollutant: Disulfoton LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Disulfoton. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

DECISION ID

158307

Region 1

Smith River HU, Delilah Creek

Pollutant:	Cyhalothrin, Lambda
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 110271 has been replaced by LOE 349925 and LOE 112955 has been replaced by LOE 349911 due to a reassessment of data using the UC Davis Aquatic Life Criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

349944

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

349911

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

349925

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

121542

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Use and Toxicity of Pyrethroid Pesticides in the Central Valley, California, USA. Environmental Toxicology and Chemistry, 24:966-972, with erratum 24:No. 5

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158307, Cyhalothrin, Lambda	Region 1
Smith River HU, Delilah Creek

LOE ID:

325115

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lambda-cyhalothrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Water Quality Criteria Report for Lambda-cyhalothrin

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

r> Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations which are toxic to, or which produce detrimental physiological responses in, human, plant, animal, or aquatic life. (Basin Plan). Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Disulfoton is the USEPA Aquatic Life Benchmark of 0.01 ug/L for an invertebrate (chronic). Guideline Reference: OPP Aquatic Life Benchmarks Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 158199, Disulfoton	Region 1
Smith River HU, Delilah Creek

LOE ID: 324712 Pollutant: Disulfoton LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Disulfoton. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Basin: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The USEPA drinking water lifetime health advisory for disulfoton is 0.7 ug/L. The Lifetime HA is based on exposure of a 70-kg adult consuming 2 liters of a water a day. Guideline Reference: 2012 Edition of the Drinking Water Standards and Health Advisories Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP


DECISION ID	158266	Region 1
Smith River HU, Delilah Creek

Pollutant:	Cypermethrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	LOE 104322 has been replaced by LOE 349290 and LOE 108782 has been replaced by LOE 349289 due to a reassessment of data using the chronic criterion threshold. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349290

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349289

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin

Region 1 &nbs


DECISION ID	168243	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dyfonate (Fonofos or Fonophos)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168243, Dyfonate (Fonofos or Fonophos)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104285

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the freshwater aquatic life MATC for fonofos is 0.45 ug/L.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE2222)

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168243, Dyfonate (Fonofos or Fonophos)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104804

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the freshwater aquatic life MATC for fonofos is 0.45 ug/L.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168243, Dyfonate (Fonofos or Fonophos)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104286

Pollutant:

Dyfonate (Fonofos or Fonophos)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

According to the USEPA Office of Pesticide Programs Ecotoxicity database, the freshwater aquatic life MATC for fonofos is 0.45 ug/L.

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-03-11 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Smith River HU, Delilah Creek

LOE ID:

324449

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

349282

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cypermethrin. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE2222 (Delilah Creek Drainage Ditch at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2015-03-23 and 2015-03-23

Environmental Conditions:

QAPP Information:

Generic SWAMP QAPrP

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158266, Cypermethrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

347619

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Partitioning, bioavailability, and toxicity of the pyrethroid insecticide cypermethrin in sediments. Environmental Toxicology and Chemistry 21:9-15

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	161342	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104261

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115899

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115900

DECISION ID

158205

Region 1

Smith River HU, Delilah Creek

Pollutant:	EPTC (Eptam, s-ethyl dipropylthiocarbamate)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of this Regional Board decision, SWRCB staff recommend the decision be approved by the State Board.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158205, EPTC (Eptam, s-ethyl dipropylthiocarbamate)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324826

Pollutant:

EPTC (Eptam, s-ethyl dipropylthiocarbamate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA expected safe lifetime exposure limit in drinking water for EPTC, calculated using the IRIS Reference Dose, is 180 ug/L. This was calculated assuming 70 kg body weight, 2 liters/day water consumption, 20% relative source contribution from drinking water, and 0.025 mg/kg/day as the reference dose.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158205, EPTC (Eptam, s-ethyl dipropylthiocarbamate)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324829

Pollutant:

EPTC (Eptam, s-ethyl dipropylthiocarbamate)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for EPTC (eptam, s-ethyl dipropylthiocarbamate) is the USEPA Aquatic Life Benchmark of 40 ug/L for a fish (chronic).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

lign="left" valign="top" width="33%">Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 324460 Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 324457 Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Municipal & Domestic Supply Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1 SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDD criterion for the protection of human health from the consumption of water and organisms is 0.00083 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road). Temporal Representation: The samples were collected between the dates of 2017-06-07 and 2017-06-07 Environmental Conditions: QAPP Information: QAPP for Surface Water Ambient Monitoring Program (SWAMP) QAPP Information Reference(s): SWAMP QAPrP

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 122183 Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Sediment Matrix: Sediment Fraction: Total Beneficial Use: Cold Freshwater Habitat Number of Samples: 1 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and the results are as follows: 0 of the 1 samples exceeded the evaluation guideline for DDD (Dichlorodiphenyldichloroethane) . Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region) Objective/Criterion Reference: Water Quality Control Plan (Basin Plan) for the North Coast Region Evaluation Guideline: The evaluation guideline for Sum DDD from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDD is 28 ug/kg. (dw = Dry Weight) Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31 Spatial Representation: Data were collected from 1 station(s). Station Code(s): 103DE5776. Temporal Representation: Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161342, DDD (Dichlorodiphenyldichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID: 112525 Pollutant: DDD (Dichlorodiphenyldichloroethane) LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 0 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDD(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: The 4,4'-DDD criterion for the protection of human health from consumption of organisms only is 0.00084 ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: Data was collected from 1 station(s) (Station Code(s) 103DE5776). Temporal Representation: Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	168244	Region 1
Smith River HU, Delilah Creek

Pollutant:	Endosulfan
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168244, Endosulfan	Region 1
Smith River HU, Delilah Creek

LOE ID:

117837

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan, Total criterion for the protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168244, Endosulfan	Region 1
Smith River HU, Delilah Creek

LOE ID:

117839

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for total endosulfan, which is the sum of alpha endosulfan and beta endosulfan, to protect aquatic life in freshwater as criterion continuous concentration (expressed as a 4-day average) is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168244, Endosulfan	Region 1
Smith River HU, Delilah Creek

LOE ID:

115483

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168244, Endosulfan	Region 1
Smith River HU, Delilah Creek

LOE ID:

115480

Pollutant:

Endosulfan

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Endosulfan, Total criterion for the protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	161331	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115726

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

114387

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

122182

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Sum DDE from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDE is 31.3 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324470

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water


DECISION ID	158202	Region 1
Smith River HU, Delilah Creek

Pollutant:	Endosulfan sulfate
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

Commercial or recreational collection of fish, shellfish, or organisms

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

The established numeric criteria for endosulfan sulfate to protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

SpatiAmbient Monitoring Program for the 2026 Integrated Report in Region 1

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

324466

DDE (Dichlorodiphenyldichloroethylene)

Commercial or recreational collection of fish, shellfish, or organisms

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

The 4,4'-DDE criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

The samples were collected between the dates of 2017-06-07 and 2017-06-07

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

115728

DDE (Dichlorodiphenyldichloroethylene)

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161331, DDE (Dichlorodiphenyldichloroethylene)	Region 1
Smith River HU, Delilah Creek

114400

DDE (Dichlorodiphenyldichloroethylene)

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDE(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

The 4,4'-DDE criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

al Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

LOE ID:

117834

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for endosulfan sulfate to protect of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

LOE ID:

324784

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for endosulfan sulfate to protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

LOE ID:

324786

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for endosulfan sulfate to protect of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

LOE ID:

115476

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for endosulfan sulfate to protection of human health from consumption of organisms only is 240 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158202, Endosulfan sulfate	Region 1
Smith River HU, Delilah Creek

LOE ID:

115478

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The established numeric criteria for endosulfan sulfate to protect of human health from the consumption of water and organisms is 110 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program


DECISION ID	161320	Region 1
Smith River HU, Delilah Creek

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324478

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324482

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

324477

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

DECISION ID

158203

Region 1

Smith River HU, Delilah Creek

Pollutant:	Endrin
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

115489

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for endrin to protect human health from consumption of organisms only is 0.81ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:dth="33%">LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Field, Habitat, Toxicity, WQ from the Surface Water Ambient Monitoring Program for the 2026 Integrated Report in Region 1

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 103DE5776 (Delilah Creek at Sarina Road).

Temporal Representation:

The samples were collected between the dates of 2017-06-07 and 2017-06-07

Environmental Conditions:

QAPP Information:

QAPP for Surface Water Ambient Monitoring Program (SWAMP)

QAPP Information Reference(s):

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

105824

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

104779

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for endrin to protect aquatic life in freshwater as criterion continuous concentration (expressed as a 4-day average) is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

104785

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115562

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

108693

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 3 samples were collected, 3 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2013-08-07 to 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115112

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

121643

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The evaluation guideline for Sum DDT from MacDonald et al., 2000a which states that the probable effect concentration for Sum DDT is 62.9 ug/kg. (dw = Dry Weight)

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data were collected from 1 station(s). Station Code(s): 103DE5776.

Temporal Representation:

Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operatalign="top" width="33%">Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for endrin to protect of human health from the consumption of water and organisms is 0.76 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1
Smith River HU, Delilah Creek

LOE ID:

121742

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. There shall be no bioaccumulation of pesticide concentrations found in bottom sediments or aquatic life. (Water Quality Control Plan for the North Coast Region)

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115110

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

109175

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

104217

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB1 Irrigated Lands Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the objective and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The 4,4'-DDT criterion for the protection of human health from the consumption of water and organisms is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Data was collected from 1 station(s) (Station Code(s) 103DE5776).

Temporal Representation:

Date for this waterbody was collected over the date range 2015-06-24 to 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 161320, DDT (Dichlorodiphenyltrichloroethane)	Region 1
Smith River HU, Delilah Creek

LOE ID:

115416

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

The Total DDT criterion for the protection of human health from consumption of organisms only is 0.00059 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

> Evaluation Guideline: The evaluation guideline for Endrin from MacDonald et al., 2000a which states that the probable effect concentration for Endrin is 207 ug/kg. (dw = Dry Weight) Guideline Reference: Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31 Spatial Representation: Data were collected from 1 station(s). Station Code(s): 103DE5776. Temporal Representation: Data for this waterbody were collected over the date range 2015-06-24 to 2015-06-24 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1
Smith River HU, Delilah Creek

LOE ID: 117845 Pollutant: Endrin LOE Subgroup: Pollutant-Water Matrix: Water Fraction: Total Beneficial Use: Commercial or recreational collection of fish, shellfish, or organisms Number of Samples: 3 Number of Exceedances: 0 Data and Information Type: PHYSICAL/CHEMICAL MONITORING Data Used to Assess Water Quality: Water Board staff assessed SWAMP RWB1 Monitoring data for Smith River HU, Delilah Creek to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality standard for Endrin. Data Reference: Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring . SWAMP Data: SWAMP Water Quality Objective/Criterion: Water Quality Control Plan, North Coast Region (NCRWQCB 2018): All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in human, plant, animal, or aquatic life. The established numeric criteria for endrin to protect human health from consumption of organisms only is 0.81ug/L (California Toxics Rule, 2000). Objective/Criterion Reference: Water Quality Standards 2000. Establishment of numeric criteria for priority toxic pollutants for the State of California: Rules and regulations. Federal Register Vol. 65, No. 97. Washington, D.C.: Environmental Protection Agency Evaluation Guideline: Guideline Reference: Spatial Representation: The samples were collected at 1 monitoring site(s) (103DE5776) Temporal Representation: The samples were collected between the dates of 2013-08-07 and 2013-11-05 Environmental Conditions: QAPP Information: Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program QAPP Information Reference(s): Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 158203, Endrin	Region 1


DECISION ID	168242	Region 1
Smith River HU, Delilah Creek

Pollutant:	Dacthal
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list. The readily available data and information is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating.

State Board Review of Regional Board Conclusion and Recommendation:

State Board Decision Recommendation:	After review of the available data and information, SWRCB staff concludes that the water body-pollutant combination should not be placed on the section 303(d) list because it cannot be determined if applicable water quality standards are not being exceeded.

Listing Extent:

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

113423

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Lifetime Health advisory level for Dacthal is 0.07 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2013-08-07 and 2013-11-05

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

115413

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses (Water Quality Control Plan, North Coast Basin).

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

The USEPA Lifetime Health advisory level for Dacthal is 0.07 mg/L.

Guideline Reference:

2012 Edition of the Drinking Water Standards and Health Advisories

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

115411

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Irrigated Lands Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference:

Quality Assurance Program Plans, Quality Assurance Project Plans, and Standard Operating Procedures for the SWAMP program

Spatial Representation:

The samples were collected at 1 monitoring site(s) (103DE5776)

Temporal Representation:

The samples were collected between the dates of 2015-06-24 and 2015-06-24

Environmental Conditions:

QAPP Information:

Quality Assurance Program Plan and Standard Operating Procedures for SWAMP program

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 168242, Dacthal	Region 1
Smith River HU, Delilah Creek

LOE ID:

109170

Pollutant:

Dacthal

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Water Quality Assessment Data for the 2018 solicitation cycle submitted through CEDEN for SWAMP RWB1 Monitoring .

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan (Basin Plan) for the North Coast Region

Evaluation Guideline:

Guideline Reference: