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

Supporting Information

Regional Board 1 - North Coast Region

Water Body Name:	Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough
Water Body ID:	CAR1100004020140113044906
Water Body Type:	River & Stream


DECISION ID	161524	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	A Source Unknown
TMDL Priority:	Low
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	The State Water Board’s Water Quality Control Plan for Inland Surface Waters, Enclosed Bays, and Estuaries of California (the “ISWEBE Plan”) was adopted on August 7, 2018, and contains bacteria water quality objectives applicable to the REC-1 beneficial use. This has resulted in a change from assessing fecal coliform to assessing E. coli in fresh water and Enterococcus in saline water. Fecal coliform and freshwater enterococcus lines of evidence used in previous REC-1 beneficial use indicator bacteria decisions in the North Coast Region are not included in the 2026 Integrated Report assessment. The pollutant will again be considered for placement on the CWA section 303(d) List under sections 3.2 of the Listing Policy. In accordance with section 6.1.5.3 of the Listing Policy, data should be representative of the critical timing that the pollutant is expected to impact the waterbody. Lacking constant inputs, indicator bacteria do not persist in the environment for a long period and effects are of relatively short duration. As a result, the historic levels of E. coli in the waterbody may be a poor indicator of current risks to human health, particularly when more recent data are available to sufficiently assess the water quality standard. Historic lines of evidence for data collected prior to October 21, 2012 (i.e., data collected more than 10 years from the 2026 data solicitation cutoff date) were evaluated pursuant to these considerations and, when sufficient recent data were available, the pre-October 21, 2012, data were not used to assess water quality standards attainment because they do not meet the temporal representation requirements of section 6.1.5.3 of the Listing Policy. Data was not available to make a beneficial use support determination, so data collected prior to October 21, 2012, were also used in the assessment. Seven lines of evidence are available in the administrative record to assess this pollutant. ELK RIVER has two LOEs (321890, 357934) and 5 of 13 STVs exceed the E. coli objective. MARTIN SLOUGH has four LOEs (321867, 321892, 357936, 357937) and 9 of 20 STVs exceed the E. coli objective. SWAIN SLOUGH has one LOE (321893) and 0 of 4 STVs exceed the E. coli objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient against placing this water segment-pollutant combination from 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. ELK RIVER has 5 of 13 STVs exceed the E. coli objective and MARTIN SLOUGH has 9 of 20 STVs exceed the E. coli objective, and this exceeds the allowable frequency in Table 4.2 of the Listing Policy. SWAIN SLOUGH has 0 of 4 STVs exceed the E. coli objective, and this is insufficient information to apply the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The listing applies to Martin Slough and the mainstem Elk River.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should not be removed from the section 303(d) list because applicable water quality standards for the pollutant are being exceeded.

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:	The listing applies to Martin Slough and the mainstem Elk River.

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321890

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 3 of the 11 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use where the salinity is less than 1 parts per thousand 95 percent or more of the time applies a statistical threshold value to E. coli of 320 cfu/100 mL, not to be exceeded by more than 10 percent of samples within a calendar month (ISWEBE 2018).

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110EL1278 (Elk River at Hwy 101).

Temporal Representation:

The samples were collected between the days of 2016-02-16 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

357934

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

321890

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110EL1278 (Elk River at Hwy 101).

Temporal Representation:

The samples were collected between the days of 2016-02-16 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

357934

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Two of two samples exceed the water quality objective for the REC-1 beneficial use.

Data Reference:

Data for bacteria in various North Coast Region water bodies

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Elk River at Berta (Site ID E013).

Temporal Representation:

The samples were collected on 9/26/2009 and 10/14/2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.

QAPP Information Reference(s):

The State Board QA officer has determined this data to be of sufficient quality to be used in the integrated report without a QAPP. Data for future cycles will follow an approved QAPP.

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321892

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 1 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110MS6750 (Martin Slough at Campton and Fern Streets).

Temporal Representation:

The samples were collected between the days of 2017-07-25 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidenceleft" valign="top" width="33%">Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Two of two samples exceed the water quality objective for the REC-1 beneficial use.

Data Reference:

Data for bacteria in various North Coast Region water bodies

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Elk River at Berta (Site ID E013).

Temporal Representation:

The samples were collected on 9/26/2009 and 10/14/2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.

QAPP Information Reference(s):

The State Board QA officer has determined this data to be of sufficient quality to be used in the integrated report without a QAPP. Data for future cycles will follow an approved QAPP.

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321892

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 1 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110MS6750 (Martin Slough at Campton and Fern Streets).

Temporal Representation:

The samples were collected between the days of 2017-07-25 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

357936

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Three of four samples exceed the STV objective for the REC-1 beneficial use.

Data Reference:

Data for bacteria in various North Coast Region water bodies

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Martin Slough at Campton and Fern (Site ID E007)

Temporal Representation:

The samples were collected from 9/15/2008 to 10/14/2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.

QAPP Information Reference(s):

The State Board QA officer has determined this data to be of sufficient quality to be used in the integrated report without a QAPP. Data for future cycles will follow an approved QAPP.

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321893

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Region 1

Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

357936

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Three of four samples exceed the STV objective for the REC-1 beneficial use.

Data Reference:

Data for bacteria in various North Coast Region water bodies

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Martin Slough at Campton and Fern (Site ID E007)

Temporal Representation:

The samples were collected from 9/15/2008 to 10/14/2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.

QAPP Information Reference(s):

The State Board QA officer has determined this data to be of sufficient quality to be used in the integrated report without a QAPP. Data for future cycles will follow an approved QAPP.

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321893

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 0 of the 4 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110SS9000 (Swain Slough at Elk River Road).

Temporal Representation:

The samples were collected between the days of 2017-07-25 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

321867

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Coastal Pathogen TMDL data for Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough to determine beneficial use support and the results are as follows: 3 of the 10 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ from the RWQCB1 TMDL for the 2026 Integrated Report in Region 1

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): 110MS1481 (Martin Slough at Pine Hill Road).

Temporal Representation:

The samples were collected between the days of 2016-02-16 and 2018-01-10 .

Environmental Conditions:

QAPP Information:

QAPP for RWQCB1_RussianRiver

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402682

QAPP Information Reference(s):

North Coast Regional Water Quality Control Board - QA Doc (2015) - RWQCB1 Russian River TMDL - 402683

Line of Evidence (LOE) for Decision ID 161524, Indicator Bacteria	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

LOE ID:

357937

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Two of two samples exceed the STV objective for the REC-1 beneficial use.

Data Reference:

Data for bacteria in various North Coast Region water bodies

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Inland Surface Waters, Enclosed Bays, and Estuaries Plan. Part 1: Trash Provisions; Part 2: Tribal Subsistence Beneficial Uses and Mercury Provisions; Part 3: Bacteria Provisions and Variance Policy

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at Martin Slough at Fairway (Site ID E012).

Temporal Representation:

The samples were collected from 9/15/2008 to 10/14/2009.

Environmental Conditions:

QAPP Information:

The samples were collected under the Redwood Community Action Agency's Humboldt Bay First Flush Quality Assurance Project Plan.

QAPP Information Reference(s):

The State Board QA officer has determined this data to be of sufficient quality to be used in the integrated report without a QAPP. Data for future cycles will follow an approved QAPP.

n="top" width="33%">SWAMP Data:


DECISION ID	168440	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Sediment
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Sources:	Logging Road Construction/Maintenance \| Road Construction \| Silviculture
TMDL Name:	Upper Elk River and Upper Little South Fork Elk River Sediment TMDL
TMDL Project Code:	93
Date TMDL Approved by USEPA:	04/04/2018
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	Regional Board Conclusion: The pollutant name has been changed from "sedimentation/siltation" to "sediment". The pollutant was considered for placement on the section 303(d) list in a previous assessment cycle. No new information was reviewed for this current assessment cycle, however there is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. The previous conclusion remains unchanged, and is as follows: The "Eureka Plain HU, Elk River" water body has been split into three water bodies for the current Integrated Report cycle: (1) Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough, (2) Eureka Plain HU, Elk River Watershed, Upper Elk River, and (3) Eureka Plain HU, Elk River Watershed, Upper Little South Fork Elk River. LOE 47457 is a copy of placeholder LOE 3667 from the 2006 Listing cycle. There are no new data for this water segment-pollutant combination for the current Integrated Report cycle. Regional Water Board conclusion: This pollutant was considered for placement on the section 303(d) List in a previous Integrated Report cycle. No new information was reviewed for this current Integrated Report cycle. Therefore, the previous conclusion remains unchanged, and is as follows: 303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed. This listing applies to the entire waterbody. This listing applies to the entire waterbody.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current cycle. The decision has not changed.

State Board Review of Regional Board Conclusion and Recommendation:	This listing applies to the entire waterbody.

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

Listing Extent:	This listing applies to the entire waterbody.


DECISION ID	157844	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Alkalinity as CaCO3
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:


DECISION ID	157840	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Oxygen, Dissolved
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:


DECISION ID	163012	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Specific Conductivity
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:


DECISION ID	157842	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Temperature, water
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:


DECISION ID	157843	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough

Pollutant:	Turbidity
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:


DECISION ID	157841	Region 1
Eureka Plain HU, Elk River Watershed, Lower Elk River and Martin Slough