Draft 2008 California 303(d)/305(b) Integrated 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
7325
 
Pollutant: Toxicity
Final Listing Decision: Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: List on 303(d) list (TMDL required list)(2006)
Revision Status Revised
Reason for Delisting: State determines water quality standard is being met
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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.

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.
 
RWQCB Board Decision / Staff 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.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 7325
 
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: 4
Number of Exceedances: 4
 
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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
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: U.S. EPA, 2002. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition, October 2002.
 
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
 
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: 29
Number of Exceedances: 0
 
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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
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/600/4-90/027F. August 1993. Washington DC
 
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
 
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: 0
Number of Exceedances: 0
 
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.
 
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):
 
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: 3
Number of Exceedances: 0
 
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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
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: U.S. EPA, 2002. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition, October 2002.
  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.
 
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.
 
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: 6
Number of Exceedances: 1
 
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.
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
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: U.S. EPA, 2002. Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition, October 2002.
 
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.
 
DECISION ID
9490
 
Pollutant: Copper, Dissolved
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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 for 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. Three of seven samples exceeded the CTR freshwater criteria (chronic) and this exceeds 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 met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 9490
 
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: 7
Number of Exceedances: 3
 
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: 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
 
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
16193
 
Pollutant: Indicator Bacteria
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: This pollutant is being considered for placement on the section 303(d) list under section 3.3 of the Listing Policy. Under section 3.3 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 in favor of 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. Five of six samples exceed the Basin Plan single single sample water quality objectives for indicator bacteria in fresh water and this exceeds the allowable frequency listed in Table 3.2 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 met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 16193
 
LOE ID: 26867
 
Pollutant: Indicator Bacteria
LOE Subgroup: Pollutant-Water
Matrix: Water
Fraction: None
 
Beneficial Use: Water Contact Recreation
 
Number of Samples: 6
Number of Exceedances: 5
 
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: 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
 
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
  Basin Plan Amendments to the Water Quality Control Plan Los Angeles Region R4 Basin Plan as of 02/02/2009
 
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): 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
9491
 
Pollutant: Lead
Final Listing Decision: List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision: New Decision
Revision Status Revised
Sources: Source Unknown
Expected TMDL Completion Date: 2021
Impairment from Pollutant or Pollution: Pollutant
 
Weight of Evidence: 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 in favor of 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. Two of six samples exceed the California Toxics Rule Criterion Continuous Concentration for Copper and this exceeds 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 met.
 
RWQCB Board Decision / Staff Recommendation: After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.
 
SWRCB Board Decision / Staff Recommendation:
 
USEPA Decision:
 
 
Lines of Evidence (LOEs) for Decision ID 9491
 
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: 6
Number of Exceedances: 2
 
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: 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
 
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 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): 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