Draft California 2020 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Walnut Creek Wash (Drains from Puddingstone Res)
Water Body ID:	CAR4053100019980918112433
Water Body Type:	River & Stream


DECISION ID	75497	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Toxicity
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Reason for Delisting:	Flaws in original listing
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.6 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. LOE 4270 is a placeholder LOE for a decision made prior to 2006. LOE 25394 contains the original listing data that is not listed in LOE 4270. As such, LOE 4270 has been disassociated from the decision. Five lines of evidence are available in the administrative record to assess the pollutant. One additional line of evidence is available in the current listing cycle. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the 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. Five out of 42 samples exhibit toxicity to Ceriodaphnia. However, four toxic results occurred in samples from 1992-93. In between 2003 and 2007, only one of 38 samples exhibited toxicity, thus significant improvements in survival and reproduction endpoints have been observed in the most recent timeframe. All of these toxicity results were measured in water samples, which are more responsive to changing pollutant loads, and in this case reflect decreasing loads. Based on the improving trend in water quality conditions and only one toxic result in the past four years, it is evident that beneficial uses are being supported. 4. Based on more recent monitoring and available monitoring data, USEPA has determined that Walnut Creek is not impaired for toxicity and a TMDL is not required. 5. Pursuant to section 4.11 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 be removed from the section 303(d) list because applicable water quality standards for the pollutant are not 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.

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

25396

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One of six samples exhibited significant toxicity to Ceriodaphnia. Six grab samples from two sites were used to test toxicity to two species: Fathead Minnow and Ceriodaphnia.

Data Reference:

County Sanitation Districts of Los Angeles County 2003-2006 Toxicity Testing in Walnut Creek data.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan states that there shall be no acute or chronic toxicity in ambient waters outside mixing zones.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Toxicity was defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing (parametric Dunnett's Test or non-parametric Kruskal-Wallis or Wilcoxon Two-sample Test).

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. EPA 600/4-90/27.

Spatial Representation:

Samples were taken at two monitoring stations, site Nos. 1 and 2, in Walnut Creek at Baldwin Park Blvd and Merced Ave.

Temporal Representation:

Monthly toxicity samples from were taken from August 2003 to October 2003.

Environmental Conditions:

QAPP Information:

Data was collected as detailed in Sanitation Districts of Los Angeles County QA/QC Memo.

QAPP Information Reference(s):

County Sanitation Districts of Los Angeles County QA/QC Memo for 2003 Toxicity testing in Walnut Creek.

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

4270

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

28167

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero out of three samples exhibited significant toxicity. Samples were taken from two sites and tested for acute and chronic toxicity to Ceriodaphnia.

Data Reference:

Toxicity Monitoring in Walnut Creek 2005 to 2007.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan states that there shall be no acute or chronic toxicity in ambient waters outside mixing zones.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Toxicity was defined as a reduction of the NOEC below 100% and was considered significant if the effect on the sample exposure was greater than 25%. Chronic toxicity is further expressed as toxic units (TUc), where TUc = 100/NOEC.
The No Observable Effect Concentration (NOEC) is expressed as the maximum percent of receiving water that causes no observable effect on a test organism, as determined by the result of a critical life stage toxicity test. The NOEC is defined, in USEPA, 2002 as the the lowest concentration of toxicant to which organisms are exposed in a life-cycle or partial life-cycle (short-term) test, which causes adverse effects on the test organisms (i.e., where the values for the observed responses are statistically significantly different from the controls).

Guideline Reference:

FINAL Calleguas Creek Watershed Toxicity, Chlorpyrifos and Diazinon TMDL Technical Report. 2005. Submitted to Los Angeles Regional Water Quality Control Board. Prepared by Larry Walker Associates on behalf of the Calleguas Creek Watershed Management Plan. June 21, 2005.

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. EPA 600/4-90/27.

Spatial Representation:

Samples were taken from two monitoring stations, site SGLT506 and SGUT506, in Walnut Creek.

Temporal Representation:

Samples were taken on 07/25/2005, on 07/19/2006, and on 06/11/2007.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and monitoring procedures detailed in San Gabriel River Regional Monitoring Program Quality Assurance Project Plan.

QAPP Information Reference(s):

San Gabriel River Regional Monitoring Program Quality Assurance Project Plan. San Gabriel River Regional Monitoring Program.

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

25399

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Zero out of 29 samples exhibited significant toxicity. Samples were taken from two sites and tested for toxicity to Ceriodaphnia.

Data Reference:

Technical Report 493: Wet and Dry Weather Toxicity in the San Gabriel River.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan states that there shall be no acute or chronic toxicity in ambient waters outside mixing zones.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Toxicity was defined as a statistically significant effect in the sample exposure compared to the control using EPA recommended hypothesis testing (parametric Dunnett's Test or non-parametric Fisher's Exact Test).

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. EPA 600/4-90/27.

Spatial Representation:

Samples were taken from two monitoring stations, site Nos. 1 and 2, in Walnut Creek at Baldwin Park Blvd and Merced Ave.

Temporal Representation:

Monthly dry-weather samples were taken from March 2005 to August 2006 and three wet-weather samples were taken in December 2004, April 2005, and January 2006.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and monitoring procedures detailed in Southern California Coastal Water Research Project and Nautilus Environmental Quality's Assurance Project Plan.

QAPP Information Reference(s):

Evaluation of Toxicity in the San Gabriel River Watershed Quality Assurance Project Plan

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

25394

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

Four of four samples exhibited significant toxicity. Four samples from one site were used to test toxicity to three species: Fathead Minnow, Ceriodaphnia, and Selanastrum. The samples had no effect on Selanastrum, but had effects on the other species used in the testing. A toxicity identification evaluation (TIE) was conducted for one of the samples and data suggest that an organic constituent was responsible for toxicity.

Data Reference:

Toxicity Study of the Santa Clara River, San Gabriel River, and Calleguas Creek. Final Report. Prepared by Aquatic Toxicology Laboratory, Department of Medicine, School of Veterinary Medicine, University of California Davis.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan states at there shall be no acute or chronic toxicity in ambient waters outside mixing zones.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms, Fourth Edition. EPA 600/4-90/27.

Spatial Representation:

Samples were taken at monitoring station, SG-8, in Walnut Creek at Baldwin Park Blvd.

Temporal Representation:

Quarterly toxicity samples from were taken from June 1992 to March 1993.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and monitoring procedures detailed in University of California Davis' Work/QA Project Plan.

QAPP Information Reference(s):

Toxicity Study of the Santa Clara River, San Gabriel River, and Calleguas Creek Toxicity Work/QA Project Plan

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

28004

Pollutant:

Toxicity

LOE Subgroup:

Narrative Description Data

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Based on additional monitoring and assessment of the available monitoring data, USEPA has determined that Walnut Creek is not impaired for toxicity.

Data Reference:

Letter to National Resources Defense Council, Heal the Bay, and Santa Monica Baykeeper determining no impairment for toxicity in Walnut Creek. USEPA.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA info unavailable.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 75497, Toxicity	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89757

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Sediment

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

TOXICITY TESTING

Data Used to Assess Water Quality:

One sample was collected to evaluate sediment toxicity. The sample exhibited significant toxicity. The toxicity test included survival and growth of Hyalella azteca. One sample can have multiple toxicity test results but will be counted only once.

Data Reference:

Statewide Project Urban Pyrethroid Status 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. Region 4 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Toxicity is defined as a statistically significant effect in the sample exposure compared to the control using EPA-recommended hypothesis testing. For SWAMP data exceedances are counted with the significant effect code SL. SL is defined as the result being significant compared to the negative control based on a statistical test, less than stated the alpha level, AND less than the evaluation threshold.

Guideline Reference:

Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates, Second Edition. U.S. Environmental Protection Agency Office of Research and Development, Duluth, MI , U.S. Environmental Protection Agency Office of Water, Washington, DC EPA-600/R-99/064

Spatial Representation:

The sample was collected at station 405SUP099.

Temporal Representation:

The sample was collected in January 2007.

Environmental Conditions:

QAPP Information:

All data was collected following the Standard Operating Procedures and Data Quality Objectives outlined in the SWAMP QAMP, (Puckett, 2002). QA data are included in submission.

QAPP Information Reference(s):


DECISION ID	77230	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Benthic Community Effects
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2012
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for the section 303(d) list under section 3.9 of the Listing Policy. Under section 4.9, waters are listed when a bioassessment shows diminished numbers of species or other metrics (compared to a reference site) and it is associated with another pollutant. Two lines of evidence are available in the administrative record to assess this pollutant. Benthic macroinvertebrates as measured by Southern California IBI (index of biological integrity) in Walnut Creek were very poor in 2003, 2004, 2006, 2007 and 2008 indicating impairment of benthic community structure. 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. There is at least 2 bioassessment sample (Index of Biological Integrity score) to satisfy Section 3.9. This water body is also listed for bacteria and pH impairments. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are met. State Board Review and Conclusion: State Water Board staff used a situation-specific weight of evidence approach to evaluate the Los Angeles Water Board benthic macroinvertebrate¿bioassessment listing. State Water Board staff determined that it is necessary to include these listings because additional data analyses and multiple line of evidence show that benthic macroinvertebrate populations are impacted by a wide range of stressors. Using this approach staff followed a three-step process for evaluation of all available water quality data including the chemistry, bioassessment data, and toxicity. In the first step, staff reviewed the Los Angeles Water Board data evaluation for bioassessment listing. In the second step, staff reviewed all other available bioassessment data because State Water Board staff learned that some data had not been considered for this listing decision by the Regional Water Board. In step 3 staff reviewed the chemistry water quality data available for Indicator bacteria, lead, zinc, copper, mercury, and oil and grease to determine the water quality condition in this water body segment. In step 1 and 2, State Water Board staff evaluated the bioassessment data using the Southern California index of biological integrity (IBI). Staff reviewed the line of evidence prepared by the Los Angeles Water Board and additional bioassessment data. Benthic macroinvertebrate as measured by Southern California IBI in Walnut Creek were poor in 2003 and 2004 indicating impairment of benthic community structure. In step 3, the chemistry data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease were evaluated by State Water Board staff. Data for toxicity and pH were evaluated in a previous listing cycle. pH showed impairment to the warm freshwater habitat and it resulted in listing this water body in 1996. In this step State Water Board staff evaluated the most recent available data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease. The data for fecal coliform show that 5 of 6 samples exceeded the water quality objective. The data for lead show that 1 of 7 samples exceeded the water quality objective. The data for zinc show that 1 of 7 samples exceeded the water quality objective. The data for copper show that 1 of 7 samples exceeded the water quality objective. The data for mercury show that 2 of 7 samples exceeded the water quality objective. The data for oil and grease show that 1 of 6 samples exceeded the water quality objective. The weight of evidence of the data and information indicate that the beneficial use of the water is not supported. In 2010, the State Board Review and Conclusion was as follows: State Water Board staff used a situation-specific weight of evidence approach to evaluate the Los Angeles Water Board benthic macroinvertebrate¿bioassessment listing. State Water Board staff determined that it is necessary to include these listings because additional data analyses and multiple line of evidence show that benthic macroinvertebrate populations are impacted by a wide range of stressors. Using this approach staff followed a three-step process for evaluation of all available water quality data including the chemistry, bioassessment data, and toxicity. In the first step, staff reviewed the Los Angeles Water Board data evaluation for bioassessment listing. In the second step, staff reviewed all other available bioassessment data because State Water Board staff learned that some data had not been considered for this listing decision by the Regional Water Board. In step 3 staff reviewed the chemistry water quality data available for Indicator bacteria, lead, zinc, copper, mercury, and oil and grease to determine the water quality condition in this water body segment. In step 1 and 2, State Water Board staff evaluated the bioassessment data using the Southern California index of biological integrity (IBI). Staff reviewed the line of evidence prepared by the Los Angeles Water Board and additional bioassessment data. Benthic macroinvertebrate as measured by Southern California IBI in Walnut Creek were poor in 2003 and 2004 indicating impairment of benthic community structure. In step 3, the chemistry data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease were evaluated by State Water Board staff. Data for toxicity and pH were evaluated in a previous listing cycle. pH showed impairment to the warm freshwater habitat and it resulted in listing this water body in 1996. In this step State Water Board staff evaluated the most recent available data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease. The data for fecal coliform show that 5 of 6 samples exceeded the water quality objective. The data for lead show that 1 of 7 samples exceeded the water quality objective. The data for zinc show that 1 of 7 samples exceeded the water quality objective. The data for copper show that 1 of 7 samples exceeded the water quality objective. The data for mercury show that 2 of 7 samples exceeded the water quality objective. The data for oil and grease show that 1 of 6 samples exceeded the water quality objective. The weight of evidence of the data and information indicate that the beneficial use of the water is not supported. New data indicate that there continues to be an impact to the biological community in this water body. The water quality chemistry and bioassessment data provide a substantial basis that benthic macroinvertebrate populations are impacted by a wide range of anthropogenic stressors. Based on the available data and information, staff recommend to not delist for benthic macroinvertebrate-bioassessment.

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:	In 2010, the State Board Review and Conclusion was as follows: State Water Board staff used a situation-specific weight of evidence approach to evaluate the Los Angeles Water Board benthic macroinvertebrate¿bioassessment listing. State Water Board staff determined that it is necessary to include these listings because additional data analyses and multiple line of evidence show that benthic macroinvertebrate populations are impacted by a wide range of stressors. Using this approach staff followed a three-step process for evaluation of all available water quality data including the chemistry, bioassessment data, and toxicity. In the first step, staff reviewed the Los Angeles Water Board data evaluation for bioassessment listing. In the second step, staff reviewed all other available bioassessment data because State Water Board staff learned that some data had not been considered for this listing decision by the Regional Water Board. In step 3 staff reviewed the chemistry water quality data available for Indicator bacteria, lead, zinc, copper, mercury, and oil and grease to determine the water quality condition in this water body segment. In step 1 and 2, State Water Board staff evaluated the bioassessment data using the Southern California index of biological integrity (IBI). Staff reviewed the line of evidence prepared by the Los Angeles Water Board and additional bioassessment data. Benthic macroinvertebrate as measured by Southern California IBI in Walnut Creek were poor in 2003 and 2004 indicating impairment of benthic community structure. In step 3, the chemistry data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease were evaluated by State Water Board staff. Data for toxicity and pH were evaluated in a previous listing cycle. pH showed impairment to the warm freshwater habitat and it resulted in listing this water body in 1996. In this step State Water Board staff evaluated the most recent available data for indicator bacteria, lead, zinc, copper, mercury, and oil and grease. The data for fecal coliform show that 5 of 6 samples exceeded the water quality objective. The data for lead show that 1 of 7 samples exceeded the water quality objective. The data for zinc show that 1 of 7 samples exceeded the water quality objective. The data for copper show that 1 of 7 samples exceeded the water quality objective. The data for mercury show that 2 of 7 samples exceeded the water quality objective. The data for oil and grease show that 1 of 6 samples exceeded the water quality objective. The weight of evidence of the data and information indicate that the beneficial use of the water is not supported. New data indicate that there continues to be an impact to the biological community in this water body. The water quality chemistry and bioassessment data provide a substantial basis that benthic macroinvertebrate populations are impacted by a wide range of anthropogenic stressors. Based on the available data and information, staff recommend to not delist for benthic macroinvertebrate-bioassessment.

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

Line of Evidence (LOE) for Decision ID 77230, Benthic Community Effects	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89579

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Three samples were collected from Walnut Creek Wash over three years. Three of the three samples collected had IBI scores below 40. The scores were 9 (2006), 17 (2007), and 5 (2008).

Data Reference:

Bioassessment Monitoring Report in Los Angeles County, 2006-2008.

SWAMP Data:

Non-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 or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked. For the Southern California IBI, sites with scores below 40 are considered to have impaired conditions.

Guideline Reference:

Development of a Benthic Index of Biotic Integrity (B-IBI) for Wadeable Streams in Northern Coastal California and its Application to Regional 305(b) Assessment

Spatial Representation:

The samples were collected from Walnut Channel upstream of San Gabriel River, station 5(SGLT-506).

Temporal Representation:

The samples were collected in 2006, 2007 and 2008.

Environmental Conditions:

QAPP Information:

Qaulity assurance is good. Los Angeles County Department of Public Works (LACDPW) contracted Weston Solutions, Inc. to perform biological assessments. Sampling and analysis followed the protocols described in the California Stream Bioassessment Procedure (CSBP) (Harrington, 2003), and also incorporated the Southern California Index of Biotic Integrity (IBI) (Ode et al., 2005).

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 77230, Benthic Community Effects	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

30227

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Cold Freshwater Habitat | Preservation of Rare & Endangered Species | Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

The IBI scores at this site ranked in the ¿very poor¿ range (7 in 2003 and 6 in 2004).

Data Reference:

Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 4, San Gabriel River Watershed Management Area, pp4.1 - 4.36.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Los Angeles RWQCB Basin Plan Objectives for Toxicity which states ¿All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or 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 appropraite methods as specified by the State or Regional Board.¿

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked according to very good (80-56), good (41-55), fair (27-40), poor (14-26) and very poor (0-13) habitat conditions. Sites with scores below 26 are considered to have impaired conditions.

Guideline Reference:

Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 4, San Gabriel River Watershed Management Area, pp4.1 - 4.36.

Guideline Reference:

Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 3, Methods, pp3.1 - 3.28

Guideline Reference:

A Quantitative Tool for Assessing the Integrity of Southern Coastal California Streams. Appendix 7-B Environmental Management Vol. 35, No. 4, pp. 493-504.

Spatial Representation:

One site in Walnut Creek was sampled, downstream of N. Baldwin Park Blvd, at N 34º 03.674¿ W 117º 59.847¿.

Temporal Representation:

Sites were sampled in October of 2003 and October of 2004.

Environmental Conditions:

Benthic macroinvertebrate populations and IBI scores may also be affected by a wide range of anthropogenic stressors.

QAPP Information:

Data was collected in compliance with California Stream Bioassessment Procedure.

QAPP Information Reference(s):

Los Angeles County 1994-2005 Integrated Receiving Water Impacts Report. Section 3, Methods, pp3.1 - 3.28

QAPP Information Reference(s):

California Stream Bioassessment Procedure (Protocol Brief for Biological and Physical/Habitat Assessment in Wadeable Streams) California Department of Fish and Game Water Pollution Control Laboratory Aquatic Bioassessment Laboratory Revision Date - December, 2003


DECISION ID	90133	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90133, Bifenthrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89580

Pollutant:

Bifenthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm 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 data for Walnut Creek Wash (Drains from Puddingstone Res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for Bifenthrin.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan for the Los Angeles Region (LARWQCB 2004): 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.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	90371	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Chlordane
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 2 samples exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 2 samples exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90371, Chlordane	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89582

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero of 1 samples collected exceeded the criteria for chlordane concentration (Sum of trans-Chlordane, cis-Chlordane, cis-Nonachlor, trans-Nonachlor, and Oxychlordane).

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. Waters shall not contain substances in concentrations that result in the deposition of material that causes nuisance or adversely affects beneficial uses. (Water Quality Control Plan for the Coastal Watersheds of Los Angeles And Ventura Counties).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Probable Effect Concentration for Chlordane in freshwater sediments is 17.6 ug/kg(MacDonald et al. 2000).

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 at the following station 405SUP099 (Walnut Creek @ Cloverleaf).

Temporal Representation:

The samples were collected on 1/8/2007.

Environmental Conditions:

QAPP Information:

The SWAMP QAPP (2008) was followed.

QAPP Information Reference(s):

Surface Water Ambient Monitoring Program Quality Assurance Program Plan

Line of Evidence (LOE) for Decision ID 90371, Chlordane	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89581

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for chlordane is 17.6 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	90190	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Chlorpyrifos
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 0 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90190, Chlorpyrifos	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89614

Pollutant:

Chlorpyrifos

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One sample result was not used in the assessment because the laboratory method detection limit was above the guideline and the result was non-detect, therefore the results could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

There is no chlorpyrifos evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: the freshwater criterion continuous concentration to protect aquatic organisms is 0.015 ug/L (Siepmann and Finlayson 2000, with minor corrections to significant figures as described in Beaulaurier et al., 2005).

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 (with minor corrections to significant figures as described in Beaulaurier et al., 2005).

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	71409	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Copper
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)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. 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 section 303(d) list in the Water Quality Limited Segments category. 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. One of six samples exceeded the CTR freshwater criteria (chronic) and this does not exceed the allowable frequency listed in Table 3.1 of the Listing Policy. 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:	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:

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

Line of Evidence (LOE) for Decision ID 71409, Copper	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

9025

Pollutant:

Copper, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Preservation of Rare & Endangered Species | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Los Angeles County Department of Public Works monitoring reports (2006-2007), submitted electronically

Data Reference:

2006-2007 Monitoring Data (MS4 Data) for Tributaries of the San Gabriel River Watershed- CI 6948 for order no. 01-182 NPDES No. CAS004001 Municipal Storm Water and Urban Runoff Discharges within the County of Los Angeles, and the Incorporated Cities therein, Except the City of Long Beach.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

CTR Dissolved Copper Criterion for continuous concentration (CCC) and maximum concentration (CMC) in water for the protection of aquatic life is expressed as a function of the total hardness of the water body. The aquatic life criteria will vary depending of total hardness reported at the sampling site. The CMC is the highest concentration of a pollutant to which aquatic life can be exposed for a short period of time without deleterious effects and the CCC is the highest concentration to which aquatic life can be exposed for an extended period of time (four days) without deleterious effects. This criterion is linked and applicable for the protection of aquatic life Beneficial Uses.

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:

One station: TS13, at the confluence of Walnut Creek and Big Dalton Wash

Temporal Representation:

Composite samples, approximately six per year (four wet-weather events and two dry-weather events), from October 2006 through April 2007.

Environmental Conditions:

QAPP Information:

Data collected for compliance with NPDES Permit No. CAS004001 Monitoring and Reporting Program.

QAPP Information Reference(s):

Monitoring and Reporting Program - CI 6948 for order no. 01-182 NPDES No. CAS004001 Municipal Storm Water and Urban Runoff Discharges within the County of Los Angeles, and the incorporated cities, except the City of Long Beach


DECISION ID	90191	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Cyfluthrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90191, Cyfluthrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89615

Pollutant:

Cyfluthrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	90312	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Cyhalothrin, Lambda
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90312, Cyhalothrin, Lambda	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89616

Pollutant:

Cyhalothrin, Lambda

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	90250	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Cypermethrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 90250, Cypermethrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89617

Pollutant:

Cypermethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	100472	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	DDD (Dichlorodiphenyldichloroethane)
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 100472, DDD (Dichlorodiphenyldichloroethane)	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89654

Pollutant:

DDD (Dichlorodiphenyldichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm 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 data for Walnut Creek Wash (Drains from Puddingstone Res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDD.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for sum of DDD is 28.0 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96160	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	DDE (Dichlorodiphenyldichloroethylene)
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96160, DDE (Dichlorodiphenyldichloroethylene)	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89655

Pollutant:

DDE (Dichlorodiphenyldichloroethylene)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm 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 data for Walnut Creek Wash (Drains from Puddingstone Res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDE.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for sum of DDE is 31.3 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96695	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	DDT (Dichlorodiphenyltrichloroethane)
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 and 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96695, DDT (Dichlorodiphenyltrichloroethane)	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89656

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm 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 data for Walnut Creek Wash (Drains from Puddingstone Res) to determine beneficial use support and results are as follows: 0 of 1 samples exceed the criterion for DDT.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for sum of DDT is 62.9 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)

Line of Evidence (LOE) for Decision ID 96695, DDT (Dichlorodiphenyltrichloroethane)	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89725

Pollutant:

Total DDT (sum of 4,4'- and 2,4'- isomers of DDT, DDE, and DDD)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for total DDTs is 572 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96696	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Deltamethrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96696, Deltamethrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89657

Pollutant:

Deltamethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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 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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96867	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Diazinon
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96867, Diazinon	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89658

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

There is no diazinon evaluation guideline specific to "sediment, interstitial water" (pore water). The following evaluation guideline was used to evaluate an exceedance in water quality standards: 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:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96846	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96846, Dieldrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89689

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for dieldrin is 61.8 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96847	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Endrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96847, Endrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89690

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for endrin is 207 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96848	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Esfenvalerate/Fenvalerate
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exhibited sediment toxicity. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96848, Esfenvalerate/Fenvalerate	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89691

Pollutant:

Esfenvalerate/Fenvalerate

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for esfenvalerate/fenvalerate is the median lethal concentration (LC50) of 1.5 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1.5 ug/g is the geometric mean of LC50 values for esfenvalerate/fenvalerate 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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96849	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Fenpropathrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least two lines of evidence are necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96849, Fenpropathrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89692

Pollutant:

Fenpropathrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for fenpropathrin is the median lethal concentration (LC50) of 1 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 1 ug/g is the geometric mean of LC50 values for fenpropathrin 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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	95954	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Fipronil
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 0 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 95954, Fipronil	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89693

Pollutant:

Fipronil

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

One of one sample result was non-detect. It was not used in the assessment because after the laboratory method detection limit value was organic carbon normalized the result was above the guideline, therefore the result could not be quantified with the level of certainty required by the Listing Policy.

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for fipronil is the median lethal concentration (LC50) of 0.13 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Effect of sediment-associated pyrethroids, fipronil, and metabolites on Chironomus tentans growth rate, body mass, condition index, immobilization, and survival. Environ. Toxicol. Chem. 27(12):2582-2590.

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	95955	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Fipronil Sulfide
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 0 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 95955, Fipronil Sulfide	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89721

Pollutant:

Fipronil Sulfide

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for fipronil sulfide is the median lethal concentration (LC50) of 0.16 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	95956	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Fipronil Sulfone
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 0 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 95956, Fipronil Sulfone	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89722

Pollutant:

Fipronil Sulfone

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for fipronil sulfone is the median lethal concentration (LC50) of 0.12 ug/g and is normalized by the percentage of organic carbon in the sediment sample (Maul et al. 2008).

Guideline Reference:

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	72214	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Lead
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)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the 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. One line of evidence is available in the administrative record to assess this pollutant. 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 section 303(d) list in the Water Quality Limited Segments category. 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. One of six samples exceeded the California Toxics Rule Criterion Continuous Concentration for Lead and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 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:	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:

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

Line of Evidence (LOE) for Decision ID 72214, Lead	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

9027

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Aquatic Life Use:

Preservation of Rare & Endangered Species | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fixed station physical/chemical (conventional plus toxic pollutants)

Data Used to Assess Water Quality:

Los Angeles County Department of Public Works monitoring reports (2006-2007), submitted electronically

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One station: TS13, at the confluence of Walnut Creek and Big Dalton Wash

Temporal Representation:

Composite samples were taken approximately six per year (four wet-weather events and two dry-weather events), from October 2006 through April 2007.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and monitoring procedures detailed in County of Los Angeles MS4 Permit (NPDES No. CAS004001) Monitoring and Reporting Program.

QAPP Information Reference(s):


DECISION ID	95957	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Lindane/gamma Hexachlorocyclohexane (gamma-HCH)
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 95957, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89723

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

In freshwater sediments the probable effect concentration (predictive of sediment toxicity for sediment-dwelling organisms) for Lindane (gamma-HCH) is 4.99 ug/Kg dry weight (MacDonald et al. 2000).

Guideline Reference:

Development and evaluation of consensus-based sediment quality guidelines for freshwater ecosystems. Environmental Contamination and Toxicology. 39: 20-31

Spatial Representation:

Data for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	96017	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Permethrin
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)(2016)
Revision Status	Original
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 3.6 of the Listing Policy. Under section 3.6 at least one line of evidence is necessary to assess listing status for pollutants sediment, and pollutant concentrations in sediment must be associated with sediment toxicity to justify adding that pollutant to the CWA section 303(d) List. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 1 sample exceeded the GUIDELINE. Based on the readily available data and information, the weight of evidence indicates that there is INSUFFICIENT justification FOR 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. 0 of 1 sample exceeded the GUIDELINE and this sample size is INSUFFICIENT to determine beneficial use support, with the power and confidence of the Listing Policy. There is not an associated sediment toxicity data as required by Section 3.6 of the Listing Policy. 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.

Line of Evidence (LOE) for Decision ID 96017, Permethrin	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

89724

Pollutant:

Permethrin

LOE Subgroup:

Pollutant-Sediment

Matrix:

Sediment

Fraction:

Total

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Statewide Project Urban Pyrethroid Status Monitoring

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for permethrin is the median lethal concentration (LC50) of 8.9 ug/g and is normalized by the percentage of organic carbon in the sediment sample. The LC50 8.9 ug/g is the geometric mean of LC50 values for permethrin 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 for this line of evidence for Walnut Creek Wash (Drains from Puddingstone Res) was collected at 1 monitoring site [ Walnut Creek @ Cloverleaf station (405SUP099).]

Temporal Representation:

Data was collected on a single day 1/8/2007.

Environmental Conditions:

Staff is not aware of any special conditions that might affect interpretation of the data.

QAPP Information:

SWAMP data collected before September 2008 followed the QAMP (2002).

QAPP Information Reference(s):

Quality Assurance Management Plan for the State of California's Surface Water Ambient Monitoring Program. Sacramento, CA. State Water Resources Control Board. SWAMP. December 2002 (1st version)


DECISION ID	76326	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	Indicator Bacteria
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2027
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	303(d) listing decisions made prior to 2006 were not held in an assessment database and are not available in the administrative record. Even though fecal coliform is no longer the applicable indicator bacteria for fresh waters in the Los Angeles Region, studies show (Noble et al., 2003) that 80 to 90% of fecal coliform are E coli in the Los Angeles Region, and therefore the fecal coliform data used to list this waterbody is a reasonable stand in for E coli until E coli data is available. This conservative approach will limit the potential for delisting this waterbody which data has shown to be impaired for fecal indicating bacteria.

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.

Line of Evidence (LOE) for Decision ID 76326, Indicator Bacteria	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

26867

Pollutant:

Indicator Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

Other Agencies/Organizations provided monitoring data

Data Used to Assess Water Quality:

Five of six samples exceeded the Basin Plan single sample water quality objectives for indicator bacteria in fresh water and one of one sample exceeded the Basin Plan geometric mean water quality objective. Water quality samples were taken and analyzed for indicator bacteria in accordance with the Municipal Separate Storm Sewer System (MS4) permit monitoring and testing parameters.

Data Reference:

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan bacteria objectives state that to protect water contact recreation in fresh waters individual samples shall not exceed the following limits: fecal coliform density shall not exceed 400/100 ml; and E. coli density shall not exceed 235/100 ml. The bacteria objectives also establish that the geometric means of individual samples shall not exceed the following limits: the fecal coliform density shall not exceed 200/100 ml; and the E. coli density shall not exceed 126/100 ml, as a geometric mean. The bacteria objectives are found in Attachment A of Regional Board Resolution No. 2001-018.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The Los Angeles County Department of Public Works conducted sampling at the mass emmission monitoring station TS13 located at the confluence of Walnut Creek and Big Dalton Wash.

Temporal Representation:

Grab samples were taken approximately six per year (four wet-weather events and two dry-weather events), from October 2006 through April 2007.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with the sampling and monitoring procedures detailed in County of Los Angeles MS4 Permit (NPDES No. CAS004001) Monitoring and Reporting Program.

QAPP Information Reference(s):


DECISION ID	69885	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

Pollutant:	pH
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Sources:	A Source Unknown
Expected TMDL Completion Date:	2007
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	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.

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:

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

Line of Evidence (LOE) for Decision ID 69885, pH	Region 4
Walnut Creek Wash (Drains from Puddingstone Res)

LOE ID:

4269

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Unspecified--This LOE is a placeholder to support a 303(d) listing decision made prior to 2006.

Data Reference:

Placeholder reference pre-2006 303(d)

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Unspecified

Objective/Criterion Reference:

Placeholder reference pre-2006 303(d)

Evaluation Guideline:

Unspecified

Guideline Reference:

Placeholder reference pre-2006 303(d)

Spatial Representation:

Unspecified

Temporal Representation:

Unspecified

Environmental Conditions:

Unspecified

QAPP Information:

Unspecified

QAPP Information Reference(s):