Final California 2024 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)
Water Body ID:	CAR4052100019990202091417
Water Body Type:	River & Stream


DECISION ID	150445	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Ammonia
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2018)
Revision Status	Revised
Reason for Delisting:	Applicable WQS attained; due to restoration activities
TMDL Name:	Los Angeles River Nitrogen (11)
TMDL Project Code:	229
Date TMDL Approved by USEPA:	03/18/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are available in the administrative record to assess this pollutant. 0 of 152 samples exceed the objective. 0 of 81 samples exceed the objective. The fractions of ammonia are equivalent so in total, 0 of 233 samples exceed the objective. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 233 samples exceeded the objective 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:	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 because applicable water quality standards 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 150445, Ammonia	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86136

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

152

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Zero out of 152 samples exceeded the site specific basin plan objective for total ammonia as nitrogen.

Data Reference:

Letter with enclosures from the City of Los Angeles, Bureau of Sanitation, Watershed Protection Division and Regulatory Affairs Division regarding several listed water bodies in the Los Angeles River watershed and Dominguez Channel watershed

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Regional Water Quality Control Plan objective for ammonia is a function of pH, temperature, and the presence of early life stages. Site specific objectives for this waterbody are based upon the presence of early life stages and found in Table 3-4. "Site-Specific 30-day Average Objectives for Ammonia by Waterbody Reach." Site specific objectives are applied as if early life stages are absent.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected in two locations: DCT R-8 and DCT R-7.

Temporal Representation:

Samples were mostly collected weekly from 01/02/08 to 02/24/10.

Environmental Conditions:

QAPP Information:

The samples were collected by the Environmental Monitoring Division of the City of Los Angeles using a quality assurance program for all laboratory analysis. These laboratories are individually certified by the Environmental Laboratory Accreditation Program (ELAP) of the California Department of Health Services.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150445, Ammonia	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253512

Pollutant:

Nitrogen, ammonia (Total Ammonia)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Total Ammonia criterion continuous concentration (expressed as a 30-day average) to protect aquatic life in freshwater is Temperature and pH dependent, and was calculated according to the 30-day average Site Specific Objective for ammonia in freshwater for Los Angeles River Reach 4.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (775463).

Temporal Representation:

Data for this waterbody was collected over the date range 2012-02-07 to 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 150445, Ammonia	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2513

Pollutant:

Ammonia

LOE Subgroup:

Subgroup Missing

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

A TMDL and implementation plan has been approved for this water segment-pollutant combination. The Los Angeles River Nitrogen TMDL was approved by RWQCB on August 19, 2003 and subsequently approved by USEPA on March 18, 2004.

Data Reference:

Placeholder reference 2006 303(d)

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 Missing

QAPP Information Reference(s):


DECISION ID	150305	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Indicator Bacteria
Final Listing Decision:	Do Not Delist from 303(d) list (being addressed with USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Sources:	See TMDL documentation
TMDL Name:	Los Angeles River Pathogens (15)
TMDL Project Code:	238
Date TMDL Approved by USEPA:	03/23/2012
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the CWA section 303(d) List under sections 2.2 and section 4.3 of the Listing Policy. Under section 4.3 of the Policy, a minimum of one line of evidence is needed to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against removing this water segment-pollutant combination from the CWA section 303(d) List. There is sufficient justification to place it in the Being Addressed portion of the CWA 303(d) List because a TMDL has been completed and approved by RWQCB and USEPA, and is expected to result in attainment of the standard. 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. 46 of 75 samples exceeded the statistical threshold value for E. coli and these exceed the allowable frequency listed in Table 4.2 of the Listing Policy. 4. The Los Angeles River Bacteria TMDL was approved by USEPA on 03/23/2012. 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 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 150305, Indicator Bacteria	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

303138

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 15 of the 36 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): LAR_05_SEP (Los Angeles River (Sepulveda Blvd)).

Temporal Representation:

The samples were collected between the days of 2015-11-17 and 2019-12-20 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 150305, Indicator Bacteria	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

303066

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

GeoMean

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 1 of the 1 samples exceeded the geomean water quality threshold for E. coli. This is a six week rolling geomean that is calculated weekly.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The bacteria water quality objective to protect the REC-1 beneficial use for waters where the salinity is equal to or less than 1 part per thousand 95 percent or more of the time applies a rolling six-week geometric mean of E. coli, not to exceed 100 cfu/100 mL (ISWEBE 2018).

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the days of 2015-11-17 and 2019-12-20 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 150305, Indicator Bacteria	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

3914

Pollutant:

Coliform Bacteria

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Water Contact Recreation

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):

Line of Evidence (LOE) for Decision ID 150305, Indicator Bacteria	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

303102

Pollutant:

Escherichia coli (E. coli)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

STV

Beneficial Use:

Water Contact Recreation

Number of Samples:

Number of Exceedances:

Data and Information Type:

PATHOGEN MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 31 of the 39 samples exceeded the Statistical Threshold Value (STV) water quality threshold for E. coli. The STV is based on a 10% exceedance rate that is calculated monthly.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site(s), station(s): LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the days of 2015-11-17 and 2019-12-20 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138554	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	1,1,2-Trichloroethane
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 and 0 of 9 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138554, 1,1,2-Trichloroethane	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

256116

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 18 samples exceeded the water quality threshold for Trichloroethane, 1,1,2-.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138554, 1,1,2-Trichloroethane	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

85954

Pollutant:

1,1,2-Trichloroethane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

All of the samples were below criteria.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recomm. WQ criteria, chronic tox info, is 9,400 ug/L.

Guideline Reference:

Spatial Representation:

The River was sampled between Selpulveda Dr. to Sepulveda Dam.

Temporal Representation:

Two samples were collected in 2007, four samples were collected in 2008, two samples were collected in 2009, and one sample was collected in 2010.

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138535	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138535, 2,4-D (2,4-Dichlorophenoxy acetic acid)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254480

Pollutant:

2,4-D (2,4-Dichlorophenoxy acetic acid)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for dichlorophenoxyacetic acid, 2,4- (2,4-D) is the USEPA Aquatic Life Benchmark of 299.2 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138551	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 0 sample exceeded the CRITERIA. 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 CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138551, Acrolein	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

85955

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

The reporting limits for all 9 of the non-detect samples were greater than the criteria, therefore were not used in this assessment.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recomm. WQ criteria, 4-day avg. is 3 ug/L.

Guideline Reference:

Spatial Representation:

The River was sampled between Selpulveda Dr. to Sepulveda Dam.

Temporal Representation:

Two samples were collected in 2007, four samples were collected in 2008, two samples were collected in 2009, and one sample was collected in 2010.

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138551, Acrolein	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253482

Pollutant:

Acrolein

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Acrolein. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138552	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the guideline 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:	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 because applicable water quality standards 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 138552, Aldrin	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253269

Pollutant:

Aldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

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

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138553	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Alkalinity as CaCO3
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138553, Alkalinity as CaCO3	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251866

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 2 samples exceeded the water quality threshold for Alkalinity as CaCO3.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA recommended alkalinity criterion continuous concentration (CCC) for the protection of aquatic life in freshwater is a minimum value of 20,000 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2016-08-30

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	153907	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	During the 2024 cycle, the 1988 National Recommended Water Quality Criteria used to assess aluminum data was replaced with U.S. EPA’s 2018 Final Recommended Aquatic Life Criteria for Aluminum in Freshwater. Insufficient information is available to determine beneficial use support for this waterbody-pollutant combination with the statistical power and confidence required by the Listing Policy. Beneficial use support will be reassessed in a future cycle, if more data are available

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 153907, Aluminum	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

314857

Pollutant:

Aluminum

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Aluminum.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The aluminum criterion for the protection of aquatic life, is pH, total hardness, and dissolved organic carbon (DOC) dependent. When total hardness or DOC data were not available, default values based on the level III ecoregions developed by U.S EPA were substituted (EPA, 2018). When pH data were not available, the median pH value for the ecoregion, a pH value from a comparable waterbody, or a pH value from a local study in the same waterbody was used as a comparable surrogate.

Guideline Reference:

Final Aquatic Life Ambient Water Quality Criteria for Aluminum. EPA-822-R-18-001. Washington, D.C.: Office of Water, USEPA.

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138510	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 20 and 0 of 2 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138510, Antimony	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251673

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that for antimony toxicity to algae occurs at 610 ug/l. (USEPA, 1986)

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2016-08-30

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138510, Antimony	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253431

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that for antimony toxicity to algae occurs at 610 ug/l. (USEPA, 1986)

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138510, Antimony	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251979

Pollutant:

Antimony

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that for antimony toxicity to algae occurs at 610 ug/l. (USEPA, 1986)

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2016-08-30

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138511	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 19 and 0 of 19 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138511, Arsenic	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253370

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved arsenic criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 150 ug/L. The conversion factor used to convert the total fraction criterion for arsenic to dissolved fraction criterion is 1. Therefore all data was considered to be representative of the dissolved fraction. (California Toxics Rule, 2000)

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138511, Arsenic	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

85956

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

Zero of the 19 samples exceeded the criteria.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The 4-day Criterion Continuous Concentration for Total Arsenic in freshwater is 150 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138511, Arsenic	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251832

Pollutant:

Arsenic

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Arsenic.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138524	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138524, Azinphos-methyl (Guthion)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253653

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Azinphos Methyl. Although a total of 19 samples were collected, 19 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria for azinphos methyl for freshwater aquatic life protection is 0.01 ug/l (instantaneous maximum)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138524, Azinphos-methyl (Guthion)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

85957

Pollutant:

Azinphos-methyl (Guthion)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the nine samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recommended Criteria 4-day Criterion Continuous Concentration for Guthion in freshwater is 0.01 ug/L.

Guideline Reference:

Spatial Representation:

A total of nine samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

A total of nine samples, two sample in 2007, four samples in 2008, two samples in 2009, and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

Samples were collected and analyzed in accordance to the ENVIRONMENTAL MONITORING DIVISION (EMD) BUREAU OF SANITATION DEPARTMENT OF PUBLIC WORKS CITY OF LOS ANGELES submitted QUALITY ASSURANCE MANUAL (QA) dated December 2009. The Quality Assurance Manual documents the QA Program at EMD.

QAPP Information Reference(s):


DECISION ID	151610	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	Benthic Community Effects are being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, additional lines of evidence (LOEs) associating the Benthic Community Effects decision with a water or sediment concentration of pollutants other than benthic-macroinvertebrate bioassessment or habitat assessment LOEs are necessary to place a water body on the 303(d) List for Benthic Community Effects. Three line(s) of evidence evaluating benthic-macroinvertebrate bioassessment data is/are available in the administrative record to assess this indicator. Three of three benthic-macroinvertebrate samples exceed the California Stream Condition Index (CSCI) impairment threshold. A minimum of two benthic-macroinvertebrate samples are needed to assess listing status. However, based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing Benthic Community Effects in this waterbody segment 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. Three of three benthic-macroinvertebrate bioassessment samples had CSCI scores below 0.79. The available information is insufficient to determine whether the waterbody/pollutant combination should be placed on the 303(d) List of impaired waters at this time. 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 151610, Benthic Community Effects	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

305374

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:

Water Board staff assessed data for 412CE0732 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.329548817 to 0.329548817.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are lethal to or that produce significant alterations in population or community ecology or receiving water biota. In addition, the health and life history characteristics of aquatic organisms in waters affected by controllable water quality factors shall not differ significantly from those for the same waters in areas unaffected by controllable water quality factors.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The California Stream Condition Index (CSCI) is a biological scoring tool that helps aquatic resource managers translate complex data about benthic macroinvertebrates found living in a stream into an overall measure of stream health. The CSCI score is calculated by comparing the expected condition with actual (observed) results (Rehn, A.C. et al., 2015). CSCI scores range from 0 (highly degraded) to greater than 1 (equivalent to reference). CSCI scoring of biological condition are as follows (per the scientific paper supporting the development of the CSCI scoring tool): greater than or equal to 0.92 = likely intact condition, 0.91 to 0.80 = possibly altered condition, 0.79 to 0.63 = likely altered condition, less than or equal to 0.62 = very likely altered condition. Sites with scores below 0.79 are considered to have exceeded the water quality objective for the aquatic life beneficial use.

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

Samples were collected from station 412CE0732.

Temporal Representation:

Samples were collected from 7/25/2007 to 7/25/2007.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 151610, Benthic Community Effects	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

305373

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:

Water Board staff assessed data for 412CE0616 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.326284154 to 0.326284154.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

Samples were collected from station 412CE0616.

Temporal Representation:

Samples were collected from 7/24/2007 to 7/24/2007.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

Line of Evidence (LOE) for Decision ID 151610, Benthic Community Effects	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

305455

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:

Water Board staff assessed data for 412CE0232 to determine beneficial use support and the results are as follows: 1 of 1 samples exceeded the threshold. CSCI scores were from 0.721486709 to 0.721486709.

Data Reference:

California Stream Condition Index (CSCI) Scores for the 2024 Integrated Report for Region 4.

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Bioassessment in complex environments: designing an index for consistent meaning in different settings

Spatial Representation:

Samples were collected from station 412CE0232.

Temporal Representation:

Samples were collected from 6/1/2006 to 6/1/2006.

Environmental Conditions:

QAPP Information:

Data were collected using Surface Water Ambient Monitoring Program protocols

QAPP Information Reference(s):

This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.


DECISION ID	138512	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138512, Beryllium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253880

Pollutant:

Beryllium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Gold Book states that beryllium chronic toxicity to freshwater aquatic life occur at concentrations as low as 5.3 ug/L.

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138513	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 1, 0 of 64 and 0 of 13 samples exceeded the objective 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:	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 because applicable water quality standards 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 138513, Cadmium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253953

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 63 samples exceeded the water quality threshold for Cadmium.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved cadmium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 2.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-10-06

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138513, Cadmium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86098

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the thirteen samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138513, Cadmium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251853

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138513, Cadmium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251900

Pollutant:

Cadmium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2016-08-30 and 2016-08-30

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138514	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138514, Chlordane	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86099

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 15 samples exceeded the water quality criteria/objective. Chlordane, alpha-chlordane, gamma-chlordane, Heptachlor, Heptachlor Epoxide, cis-and trans Nonachlor and Oxychlordane results were added to assess this waterbody. Results were evaluated against Chlordane value. Data Used to Assess Water Quality References

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-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 CTR CCC for Chlordane is 0.0043 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of 13 samples were collected at sampling location, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138514, Chlordane	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255951

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 0 of the 6 samples exceeded the water quality threshold for Total Chlordane. Although a total of 18 samples were collected, 12 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (775463).

Temporal Representation:

Data for this waterbody was collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138514, Chlordane	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253012

Pollutant:

Chlordane

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 1 of 4 samples exceeded the water quality threshold for Total Chlordane.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The chlordane criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0043 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2018-11-22

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138515	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 10 and 0 of 35 samples exceeded the objective and this does not exceed 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 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 because applicable water quality standards 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 138515, Chloride	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243956

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 8 samples exceed the criterion for Chloride.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Chloride in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 190 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_05_SEP (34.161559, -118.465969), located in Los Angeles River (Sepulveda Blvd).

Temporal Representation:

The water samples were taken between 2/29/2016 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the provisions of the Los Angeles Municipal Separate Storm Sewer System quality control and quality assurance procedures listed in coordinated integrated monitoring plan.

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138515, Chloride	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243952

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 2 samples exceed the criterion for Chloride.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Chloride in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 190 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_04_TUJ (34.140977, -118.379127), located in Los Angeles River (Tujunga Ave).

Temporal Representation:

The water samples were taken between 12/13/2015 - 8/30/2016, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138515, Chloride	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243847

Pollutant:

Chloride

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 data from the Donald C. Tillman Wastewater Reclamation Plant to determine beneficial use support. The results are as follows: 0 out of 35 samples exceed the criterion for Chloride.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region list a site specific objective for Chloride in the Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 190 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station RSW-LATT630(R-7) (34.16174, -118.46641), located in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam).

Temporal Representation:

The water samples were taken between 2/7/2012 - 8/11/2020, per the monitoring requirements listed in the Donald C. Tillman Wastewater Reclamation Plant NPDES Permit monitoring and reporting program.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the Donald C. Tillman Wastewater Reclamation Plant NDPES Permit quality assurance provisions for water quality monitoring.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138516	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138516, Chlorine	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253831

Pollutant:

Chlorine

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Chlorine, Total Residual. Although a total of 417 samples were collected, 417 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: Chlorine residual shall not be present in surface water any concentration that causes impairment of beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA recommended chlorine criterion for the protection of aquatic ife in freshwater is 11 ug/L (4-day average).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138555	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 1, 0 of 18 and 0 of 19 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138555, Chromium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86100

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the nineteen samples exceeded the objective.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138555, Chromium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

251882

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved chromium (III) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is is hardness dependent as described in Table 1 of paragraph (b)(1). The value calculated when using a default hardness of 100 mg/L is 180 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138555, Chromium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253919

Pollutant:

Chromium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138517	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 1 of 105 and 0 of 62 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138517, Cyanide	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86109

Pollutant:

Cyanide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the 62 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (NTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for cyanide is 5.2 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138517, Cyanide	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254253

Pollutant:

Cyanide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

105

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 1 of 105 samples exceeded the water quality threshold for Cyanide.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The cyanide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5.2 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-10-06

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	149698	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 149698, DDT (Dichlorodiphenyltrichloroethane)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254169

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for DDT(p,p'). Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 149698, DDT (Dichlorodiphenyltrichloroethane)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252262

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The DDT(4,4') criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.001 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138556	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 and 0 of 7 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138556, Demeton	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253984

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 0 of the 7 samples exceeded the water quality threshold for Demeton, Total. Although a total of 19 samples were collected, 12 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recommended Water Quality criterion for demeton for freshwater aquatic life protection is 0.1 ug/l (4 day average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site (775463).

Temporal Representation:

Data for this waterbody was collected over the date range 2012-02-07 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138556, Demeton	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86110

Pollutant:

Demeton

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 18 samples for Demeton o and Demeton s exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

USEPA National Recommended Water Quality Criteria lists criterion continuous concentrations for Demeton to protect aquatic life in freshwater at 0.1 ug/L.

Guideline Reference:

Spatial Representation:

A total of nine samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

A total of nine samples, two sample in 2007, four samples in 2008, two samples in 2009, and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138519	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138519, Diazinon	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254564

Pollutant:

Diazinon

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 1 of the 12 samples exceeded the water quality threshold for Diazinon. Although a total of 34 samples were collected, 22 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The freshwater chronic value for diazinon is 0.10 ug/L (4 day average)(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

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:

The samples were collected at 1 monitoring site (775463).

Temporal Representation:

Data for this waterbody was collected over the date range 2012-05-08 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138520	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138520, Dieldrin	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254318

Pollutant:

Dieldrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dieldrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138521	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138521, Endosulfan sulfate	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254654

Pollutant:

Endosulfan sulfate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA National Recommended Water Quality Criteria toxicity threshold for endosulfan sulfate for freshwater aquatic life protection is 0.056 ug/l (24 hour average)

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138522	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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)(2018)
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 18 samples exceeded the CRITERIA. 0 of 15 samples exceeded the CRITERIA. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 0 of 15 and 0 of 18 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138522, Endrin	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254809

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endrin criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.036 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138522, Endrin	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86112

Pollutant:

Endrin

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 15 samples exceeded the water quality evaluation guideline. Results of Endrin and Endrin aldehyde were added to assess the waterboady.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.036 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of 13 samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138523	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138523, Glyphosate	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252137

Pollutant:

Glyphosate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for glyphosate is the USEPA Aquatic Life Benchmark of 11,900 ug/L for a vascular plant (acute).

Guideline Reference:

OPP Aquatic Life Benchmarks

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138525	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138525, Heptachlor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86119

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 15 samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.0038 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of 15 samples were collected at sampling locations, LA RIVER R-7 and R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138525, Heptachlor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254733

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138525, Heptachlor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252206

Pollutant:

Heptachlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The heptachlor criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138526	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138526, Heptachlor epoxide	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86120

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the fifteen samples exceeded the water quality criteria/objective.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Region 4 Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxic Rule criteria fresh aquatic life protection continuous concentration (4-day average)is 0.0038 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of ten samples were collected at sampling locations, LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Fifteen samples from 2006 - 2008 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

Samples were collected and analyzed in accordance to the Monitoring Division (EMD) Bureau of Sanitation Department of Public Works - Quality Assurance Manual (QA), dated December 2009.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138526, Heptachlor epoxide	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254924

Pollutant:

Heptachlor epoxide

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Heptachlor Epoxide. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The heptachlor epoxide criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0038 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138527	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138527, Iron	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252049

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations are intended protect freshwater aquatic organisms from chronic exposures and are expressed as 4-day average concentrations. The evaluation guideline for Iron is 1,000 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138527, Iron	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252464

Pollutant:

Iron

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138528	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138528, Lindane/gamma Hexachlorocyclohexane (gamma-HCH)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254816

Pollutant:

Lindane/gamma Hexachlorocyclohexane (gamma-HCH)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The gamma-BHC (Lindane, gamma-HCH) criterion maximum concentration to protect aquatic life in freshwater is 0.95 ug/L. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138529	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138529, Malathion	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86122

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the nine samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Freshwater Aquatic Life Protection Recommended Criteria for Maximum (Instantaneous) is 0.1 ug/L (U.S. Environmental Protection Agency, Quality Criteria for Water (1976) [The Red Book]. http://www.epa.gov/waterscience/criteria/redbook.pdf.)

Guideline Reference:

Spatial Representation:

A total of nine samples were collected at sampling location, LA River R-7 and LA RIVER R-8.

Temporal Representation:

A total of nine samples, two sample in 2007, and four samples in 2008, two samples in 2009, and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138529, Malathion	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255243

Pollutant:

Malathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Malathion. Although a total of 19 samples were collected, 19 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Aquatic life should not be affected unacceptably if the 4-day average concentration of malathion does not exceed 0.028 ug/L (UC Davis Aquatic Life Criteria).

Guideline Reference:

Aquatic life water quality criteria derived via the UC Davis method: l. Organophosphate insecticides. Reviews of Environmental Contamination and Toxicology 216:1-48.

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	150111	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 78 and 0 of 62 samples exceeded the criteria 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:	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 because applicable water quality standards 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 150111, Mercury	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86123

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the 62 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentrations (4-day average concentrations) for freshwater aquatic organisms exposure to elemental mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected monthly during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 150111, Mercury	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255141

Pollutant:

Mercury

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 78 samples exceeded the water quality threshold for Mercury.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

National Recommended Water Quality Criteria Continuous Concentration (4-day average concentrations) for freshwater aquatic organisms exposure to total mercury is 0.77 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138530	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 13 samples exceeded the CRITERIA. 0 of 18 samples exceeded the CRITERIA. 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 13 and 0 of 18 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138530, Methoxychlor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255124

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA national ambient water quality criterion for freshwater aquatic life Criterion Continuous Concentration (CCC) expressed as a 4-day average for methoxychlor is 0.03 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138530, Methoxychlor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86132

Pollutant:

Methoxychlor

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 13 samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan states "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses"

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Nationally Recommended Criteria for fresh aquatic life protection continuous concentration (4-day average)is 0.03 ug/L.

Guideline Reference:

Spatial Representation:

A total of 13 samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138531	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 0 of 0 samples exceeded the CRITERIA. 0 of 15 samples exceeded the CRITERIA. 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 and 0 of 15 samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138531, Mirex	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86134

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 15 samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Region 4 Basin Plan objective state that "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Nationally Recommended Criteria for fresh aquatic life protection continuous concentration (4-day average)is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

A total of 13 samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138531, Mirex	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255251

Pollutant:

Mirex

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Mirex. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA national recommended criterion continuous concentration for mirex for the protection of freshwater aquatic life is 0.001 µg/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138532	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138532, Naphthalene	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255060

Pollutant:

Naphthalene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant, animal, or aquatic life.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA recommended naphthalene criterion for the protection of freshwater aquatic life is 620 ug/l. (EPA 440/5-80-059)

Guideline Reference:

Ambient Water Quality Criteria for Naphthalene

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-18

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138533	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 19 and 0 of 19 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138533, Nickel	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252663

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved nickel criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 52 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138533, Nickel	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86135

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the 19 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138533, Nickel	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255051

Pollutant:

Nickel

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138534	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Two lines of evidence are 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 CWA 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. 0 of 16 and 0 of 193 samples exceeded the objective 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:	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 because applicable water quality standards 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 138534, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243953

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 8 samples exceed the criterion for Nitrate + Nitrite as N.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Nitrate + Nitrite as N in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 8 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_04_TUJ (34.140977, -118.379127), located in Los Angeles River (Tujunga Ave).

Temporal Representation:

The water samples were taken between 12/13/2015 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138534, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243856

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

193

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed data from the Donald C. Tillman Wastewater Reclamation Plant to determine beneficial use support. The results are as follows: 0 out of 193 samples exceed the criterion for Nitrate + Nitrite as N.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region list a site specific objective for Nitrate + Nitrite as N in the Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 8 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station RSW-LATT630(R-7) (34.16174, -118.46641), located in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam).

Temporal Representation:

The water samples were taken between 4/3/2012 - 10/13/2020, per the monitoring requirements listed in the Donald C. Tillman Wastewater Reclamation Plant NPDES Permit monitoring and reporting program.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the Donald C. Tillman Wastewater Reclamation Plant NDPES Permit quality assurance provisions for water quality monitoring.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138534, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243957

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Nitrate + Nitrite as N in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 8 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_05_SEP (34.161559, -118.465969), located in Los Angeles River (Sepulveda Blvd).

Temporal Representation:

The water samples were taken between 2/29/2016 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	149699	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 262 samples exceeded the OBJECTIVE 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:	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 because applicable water quality standards 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 149699, Nitrogen, Nitrate	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

302502

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 17 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2019-12-20

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 149699, Nitrogen, Nitrate	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

302570

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

237

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 237 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-14 and 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 149699, Nitrogen, Nitrate	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

302489

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-34) states that: Waters shall not exceed 10 mg/L as nitrate-nitrogen (NO3-N).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_05_SEP (Los Angeles River (Sepulveda Blvd)).

Temporal Representation:

The samples were collected between the dates of 2016-02-29 and 2019-12-20

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138536	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 22 samples exceeded the GUIDELINE 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:	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 because applicable water quality standards 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 138536, Organophosphate Pesticides	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255699

Pollutant:

Organophosphate Pesticides

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and the results are as follows: 0 of the 22 samples exceeded the water quality threshold for Organophosphorus Pesticides. Although a total of 34 samples were collected, 12 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The evaluation guideline for the protection of aquatic life from the additive effects of the organophosphate pesticides chlorpyrifos and diazinon is one toxic unit equivalent. A toxic unit equivalent is equal to the sum of chlorpyrifos and diazinon from a single sample, each having their reported concentration divided their respective evaluation guideline prior to being summed. If this results in a value greater than one, the sample is considered to be in exceedance of the water quality standard. (Bailey et al., 1997).

Guideline Reference:

Joint acute toxicity of Diazinon and Chlorpyrifos to Ceriodaphnia dubia.

Spatial Representation:

The samples were collected at 1 monitoring site (775463).

Temporal Representation:

Data for this waterbody was collected over the date range 2012-05-08 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	151917	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Two lines of evidence are 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 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. 2 of 595 samples exceeded the OBJECTIVE and this does not exceed 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 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 because applicable water quality standards 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 151917, Oxygen, Dissolved	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

307858

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

237

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 2 of 237 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-39) states that: The dissolved oxygen content of all surface waters designated as WARM shall not be depressed below 5 mg/L as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-14 and 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 151917, Oxygen, Dissolved	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86144

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

358

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 358 averages of Dissolved Oxygen concentration had 0 exceedences.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Dissolved Oxygen Water Quality Objective of all surface waters designated as Warm Fresh Water Aquatic Habitat shall not be depressed below 5mg/l.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R-7 and R-8 monitoring locations.

Temporal Representation:

Samples were collected approximately once a week from January 2005 to May 2010.

Environmental Conditions:

QAPP Information:

The quality assurance manual for the Environmental Monitoring Division Bureau of Sanitation, Department of Public Works, City of Los Angeles was provided. Toxicity testing methods and requirements are in the NPDES permit CA0056227.

QAPP Information Reference(s):


DECISION ID	138541	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138541, PCBs (Polychlorinated biphenyls)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86145

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the 15 samples exceeded the water quality evaluation guideline. Results of PCB 1016, PCB 1221, PCB 1232, PCB 1242, PCB 1248, PCB 1254, and PCB 1260 were added when assessing this waterbody

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Criteria Continuous Concentration (4-day Average) criteria is 0.014 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of 13 samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138541, PCBs (Polychlorinated biphenyls)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255638

Pollutant:

PCBs (Polychlorinated biphenyls)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for PCBs (Polychlorinated biphenyls). Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The PCB, total aroclors criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.014 ug/L. This value corresponds to the sum of aroclors 1242, 1254, 1221, 1232, 1248, 1260, and 1016 (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138538	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138538, Parathion	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255489

Pollutant:

Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Parathion, Ethyl. Although a total of 19 samples were collected, 19 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA recommended freshwater aquatic life ambient water quality chronic criteria for parathion is 0.013 ug/L.

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-09-09

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138539	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 0 and 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138539, Pentachlorophenol (PCP)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255624

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pentachlorophenol criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is pH dependent. The criterion using a default pH value of 7.8 (when pH data is not present) is 15 ug/L. (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-18

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138539, Pentachlorophenol (PCP)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86146

Pollutant:

Pentachlorophenol (PCP)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

The reporting limits for all 21 of the non-detect samples were greater than the criteria, therefore were not used in this assessment.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The California Toxic Rule, 4-day avg. at pH 7.8 is 15 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

The River was sampled between Selpulveda Dr. to Sepulveda Dam, and above the Sepulveda Flood Control Basin.

Temporal Representation:

Two samples were collected in 2006, four samples were collected in 2007, six samples were collected in 2008, two samples were collected in 2009, and one sample was collected in 2010.

Environmental Conditions:

There was no special environmental condition reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138542	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 1 of 105 and 4 of 52 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138542, Selenium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255848

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

105

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 1 of 105 samples exceeded the water quality threshold for Selenium.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The selenium criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-10-06

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138542, Selenium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86148

Pollutant:

Selenium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

Four of 52 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion continuous concentrations (4-day average) to protect aquatic life in freshwater. The CTR for selenium is 5.0 ug/L.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected monthly during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138543	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 and 0 of 9 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138543, Silver	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255979

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved silver criterion maximum concentration (CMC) to protect aquatic life in freshwater is hardnesss dependent. The criterion when calculated using a default hardness of 100 mg/L is 3.4 ug/L. This criterion was divided by 2 in order to better represent a CMC value as specified in footnote (g) of Table (b)(1) of the California Toxics Rule, 2000.

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138543, Silver	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86158

Pollutant:

Silver

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the nine samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

California Toxics Rule (CTR) lists criterion maximum concentrations for silver to protect aquatic life in freshwater (1-hour average). The silver criterion in freshwater is hardness dependent for each sample and varies based on the ambient hardness during sampling. Section (b)(1) in CTR contains the hardness dependent formula for the metals criterion. If no hardness data were available, a value of 100 mg/L was used.

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected annual or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138544	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 3 of 35 samples exceeded the objective and this does not exceed 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 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 because applicable water quality standards 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 138544, Sulfates	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243857

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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 data from the Donald C. Tillman Wastewater Reclamation Plant to determine beneficial use support. The results are as follows: 3 out of 35 samples exceed the criterion for Sulfate.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region list a site specific objective for Sulfate in the Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 300 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station RSW-LATT630(R-7) (34.16174, -118.46641), located in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam).

Temporal Representation:

The water samples were taken between 2/7/2012 - 8/11/2020, per the monitoring requirements listed in the Donald C. Tillman Wastewater Reclamation Plant NPDES Permit monitoring and reporting program.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the Donald C. Tillman Wastewater Reclamation Plant NDPES Permit quality assurance provisions for water quality monitoring.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138544, Sulfates	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243958

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 8 samples exceed the criterion for Sulfate.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Sulfate in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 300 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_05_SEP (34.161559, -118.465969), located in Los Angeles River (Sepulveda Blvd).

Temporal Representation:

The water samples were taken between 2/29/2016 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138544, Sulfates	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243954

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 8 samples exceed the criterion for Sulfate.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Sulfate in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 300 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_04_TUJ (34.140977, -118.379127), located in Los Angeles River (Tujunga Ave).

Temporal Representation:

The water samples were taken between 2/29/2016 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138545	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. Temperature is a fractionless pollutant, and the fractions "none" and "not recorded" are equivalent. The lines of evidence have been summed and compared to Table 3.2 Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 99 of 77 samples exceeded the objective and this does not exceed 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 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 because applicable water quality standards 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 138545, Temperature, water	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86159

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

358

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 358 averages of temperature had 10 exceedence.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

At no time shall warm freshwater habitat-designated waters be raised above 80 degrees Fahrenheit as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R-7 and R-8 monitoring locations.

Temporal Representation:

Samples were collected approximately once a week from January 2005 to May 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138545, Temperature, water	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255944

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

417

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 89 of 417 samples exceeded the water quality threshold for Temperature.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region (page 3-45) states that: For waters designated WARM, water temperature shall not be altered by more than 5 °F above the natural temperature. At no time shall these WARM-designated waters be raised above 80 °F as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138546	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the criteria 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:	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 because applicable water quality standards 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 138546, Thallium	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255752

Pollutant:

Thallium

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The USEPA Quality Criteria for Water (Gold Book) states that thallium chronic toxicity to one species of fish occurs at concentrations as low as 20 ug/L after 2,600 hours of exposure. (USEPA, 1986)

Guideline Reference:

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

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138547	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 3 of 45 samples exceeded the objective and this does not exceed 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 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 because applicable water quality standards 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 138547, Total Dissolved Solids	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243858

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region list a site specific objective for Total Dissolved Solids in the Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 950 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station RSW-LATT630(R-7) (34.16174, -118.46641), located in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam).

Temporal Representation:

The water samples were taken between 2/7/2012 - 8/11/2020, per the monitoring requirements listed in the Donald C. Tillman Wastewater Reclamation Plant NPDES Permit monitoring and reporting program.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the Donald C. Tillman Wastewater Reclamation Plant NDPES Permit quality assurance provisions for water quality monitoring.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138547, Total Dissolved Solids	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243959

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 8 samples exceed the criterion for Total Dissolved Solids.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Total Dissolved Solids in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 950 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_05_SEP (34.161559, -118.465969), located in Los Angeles River (Sepulveda Blvd).

Temporal Representation:

The water samples were taken between 2/29/2016 - 12/20/2019, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138547, Total Dissolved Solids	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

243955

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 data from the Los Angeles County MS4 Permit to determine beneficial use support. The results are as follows: 0 out of 2 samples exceed the criterion for Total Dissolved Solids.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region gives a site specific objective for Total Dissolved Solids in Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) of 950 mg/L.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station LAR_04_TUJ (34.140977, -118.379127), located in Los Angeles River (Tujunga Ave).

Temporal Representation:

The water samples were taken between 12/13/2015 - 8/30/2016, per the monitoring requirements listed in the Los Angeles County Municipal Separate Storm Sewer Permit.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138548	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 138548, Toxaphene	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86160

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the fifteen samples exceeded the criteria.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Criteria Continuous Concentration (4-day Average) is 0.0002 ug/L

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

A total of 15 samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

Thirteen samples from 2006 - 2010 were collected. Four samples in 2006, four samples in 2007, two samples in 2008, two samples in 2009 and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 138548, Toxaphene	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

256214

Pollutant:

Toxaphene

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Toxaphene. Although a total of 18 samples were collected, 18 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The toxaphene criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.0002 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

Data for this waterbody were collected over the date range 2012-02-07 to 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138549	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 2 of 39 samples exceeded the OBJECTIVE and this does not exceed 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 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 because applicable water quality standards 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 138549, Turbidity	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

256201

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 35 samples exceeded the water quality threshold for Turbidity.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Turbidities of 40 NTU or greater can cause a reduced foraging efficiency and a shift in prey selection in piscivorous fish (largemouth bass) due to interference with their ability to find prey (Shoup, D.E. and Wahl D.H., 2009).

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138549, Turbidity	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252813

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 2 of 4 samples exceeded the water quality threshold for Turbidity.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Water Quality Control Plan for the Los Angeles Region states that: Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

The Effects of Turbidity on Prey Selection by Piscivorous Largemouth Bass

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2016-08-30

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	138550	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 21, 3 of 72 and 0 of 19 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253086

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 7 samples exceeded the water quality threshold for Zinc.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved zinc criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is hardness dependent. The criterion when calculated using a default hardness of 100 mg/L is 120 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_05_SEP (Los Angeles River (Sepulveda Blvd)).

Temporal Representation:

The samples were collected between the dates of 2016-02-29 and 2019-12-20

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253058

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 3 of 6 samples exceeded the water quality threshold for Zinc.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2016-07-20 and 2019-11-27

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253072

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 14 samples exceeded the water quality threshold for Zinc.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2019-12-20

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

256172

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 63 samples exceeded the water quality threshold for Zinc.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-10-06

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

253075

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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 LA County MS4 data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Zinc.

Data Reference:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_05_SEP (Los Angeles River (Sepulveda Blvd)).

Temporal Representation:

The samples were collected between the dates of 2016-07-20 and 2018-05-14

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138550, Zinc	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86162

Pollutant:

Zinc

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

None of the 19 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected once or twice a year during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	138518	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 19 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138518, alpha-Endosulfan (Endosulfan 1)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

252319

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the MS4 database assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan I (alpha-endosulfan) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LAR_04_TUJ (Los Angeles River (Tujunga Ave)).

Temporal Representation:

The samples were collected between the dates of 2015-12-13 and 2015-12-13

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)

Line of Evidence (LOE) for Decision ID 138518, alpha-Endosulfan (Endosulfan 1)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254329

Pollutant:

alpha-Endosulfan (Endosulfan 1)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan I (alpha-endosulfan) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138537	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.1 of the Listing Policy. Under section 3.1 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List 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. 0 of 18 samples exceeded the CRITERIA 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:	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 because applicable water quality standards 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 138537, beta-Endosulfan (Endosulfan 2)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

254424

Pollutant:

beta-Endosulfan (Endosulfan 2)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

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:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The endosulfan II (beta-endosulfan) criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 0.056 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-07 and 2020-08-11

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program


DECISION ID	138540	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

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

Regional Board Conclusion:	This pollutant is being considered for placement on the CWA section 303(d) List under section 3.2 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the CWA section 303(d) List. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. 43 of 358 and 13 of 237 samples exceeded the OBJECTIVE and this does not exceed 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 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 because applicable water quality standards 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 138540, pH	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

255669

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

237

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed eSMR_Donald C. Tillman WWRP data for Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam) to determine beneficial use support and results are as follows: 13 of 237 samples exceeded the water quality threshold for pH.

Data Reference:

WQ data from the California Integrated Water Quality System (CIWQS) assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Water Quality Control Plan, Los Angeles Basin: the pH for inland surface waters, bays, or estuaries shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: 775463 (RSW-LATT630(R-7)).

Temporal Representation:

The samples were collected between the dates of 2012-02-14 and 2020-10-13

Environmental Conditions:

QAPP Information:

Los Angeles & San Gabriel Rivers Watershed Council. 2010. Los Angeles River Watershed-Wide Monitoring Program.

QAPP Information Reference(s):

Los Angeles River Watershed-Wide Monitoring Program

Line of Evidence (LOE) for Decision ID 138540, pH	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86147

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

358

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 358 averages of pH had 43 exceedences.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The pH of all inland surface waters shall not be depressed below 6.5 or raised above 8.5 as a result of waste discharges.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Samples were collected from the R-7 and R-8 monitoring locations.

Temporal Representation:

Samples were collected approximately once a week from January 2005 to May 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	71687	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Scum/Foam-unnatural
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:	Applicable WQS attained; due to restoration activities
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 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this water body condition. A nitrogen TMDL has been developed and approved by USEPA and an approved implementation plan is expected to result in attainment of the nitrogen standard. Qualitative information on scum/foam-unnatural alone is not sufficient to support placement on the section 303(d) list (Listing Policy section 3.7). It is expected that this TMDL will address the pollutant(s) contributing to or causing these conditions. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of removing this water segment-pollutant combination from the section 303(d) list.

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 71687, Scum/Foam-unnatural	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2514

Pollutant:

Scum/Foam-unnatural

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Data Reference:

Placeholder reference 2006 303(d)

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 Missing

QAPP Information Reference(s):


DECISION ID	71685	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Taste and odor
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:	Pollution

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this water body condition. A nitrogen TMDL has been developed and approved by USEPA and an approved implementation plan is expected to result in attainment of the nitrogen standard. Qualitative information on taste and odor alone is not sufficient to support placement on the section 303(d) list (Listing Policy section 3.7). It is expected that this TMDL will address the pollutant(s) contributing to or causing this condition.

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 71685, Taste and odor	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2515

Pollutant:

Taste and odor

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

Data Reference:

Placeholder reference 2006 303(d)

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 Missing

QAPP Information Reference(s):


DECISION ID	69398	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Copper
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
TMDL Name:	Los Angeles River Metals (13)
TMDL Project Code:	237
Date TMDL Approved by USEPA:	12/22/2005
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 4 of the 62 samples exceeded the CRITERIA. 0 of the 0 samples exceeded the CRITERIA. 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 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. 4 of 62 and 0 of 0 samples exceeded the CRITERIA and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 69398, Copper	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2519

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

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 listing decision made by USEPA for 2006.

Data Reference:

Placeholder reference 2006 303(d)

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 Missing

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 69398, Copper	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86108

Pollutant:

Copper

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

Four of the 62 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected monthly during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	72417	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Lead
Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	Delist from 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Reason for Delisting:	Applicable WQS attained; reason for recovery unspecified
TMDL Name:	Los Angeles River Metals (13)
TMDL Project Code:	237
Date TMDL Approved by USEPA:	12/22/2005
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the CWA section 303(d) List under section 4.1 of the Listing Policy. Under this section a single line of evidence is necessary to assess listing status. 2 lines of evidence are available in the administrative record to assess this pollutant. 3 of the 46 samples exceeded the CRITERIA. 0 of the 0 samples exceeded the CRITERIA. 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 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. 3 of 46 and 0 of 0 samples exceeded the CRITERIA and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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 72417, Lead	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2518

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

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 2006 303(d)

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 Missing

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 72417, Lead	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86121

Pollutant:

Lead

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Warm Freshwater 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:

Three of the 46 samples exceeded the numeric threshold.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Surface waters shall not contain concentrations of chemical constituents in amounts that adversely affect any designated beneficial use.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Code of Federal Regulations 40 part 131.38 Establishment of numeric criteria for priority toxic pollutants for the State of California. 7/1/2011 Edition

Spatial Representation:

Samples were collected from stations LA RIVER R-7 and LA RIVER R-8.

Temporal Representation:

Samples were collected monthly during the years 2007 through 2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	96981	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Methyl Parathion
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 3.1 of the Listing Policy. Under section 3.1 a single line of evidence are necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 0 of 9 samples exceeded the CRITERIA. 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 9 samples exceeded the CRITERIA and this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. A minimum of 16 samples is needed to determine if a beneficial use is fully supported using table 3.1. 4. Pursuant to SECTION 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 96981, Methyl Parathion	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86133

Pollutant:

Methyl Parathion

LOE Subgroup:

Pollutant-Water

Matrix:

Water

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:

None of the nine samples exceeded the water quality evaluation guideline.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Los Angeles Region Basin Plan objective is "No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The Department of Fish and Game instantaneous criteria for Methyl parathion; parathion, methyl is 0.08 ug/L.

Guideline Reference:

Hazard Assessment of the Insecticide Methyl Parathion to Aquatic Organisms in the Sacramento River System

Spatial Representation:

A total of three samples were collected at sampling locations, LA River R-7 and LA RIVER R-8.

Temporal Representation:

A total of nine samples, two sample in 2007, and four samples in 2008, two samples in 2009, and one sample in 2010 were collected.

Environmental Conditions:

There was no special environmental conditions reported.

QAPP Information:

QAPP Information Reference(s):


DECISION ID	100455	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Toxicity
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:	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 a single line of evidence is necessary to assess listing status. 1 line of evidence is available in the administrative record to assess this pollutant. 21 of 48 samples exceeded the GUIDELINE. 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 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. 21 of 48 samples exceeded the GUIDELINE 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 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 placed on the section 303(d) list because applicable water quality standards are exceeded and a pollutant contributes to or causes the problem.

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 100455, Toxicity	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

86161

Pollutant:

Toxicity

LOE Subgroup:

Toxicity

Matrix:

Water

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:

Forty-eight samples were collected to evaluate water toxicity. Twenty-one of the 48 samples exhibited significant toxicity. The toxicity tests included acute and chronic toxicity. The species and methods used can be found in the NPDES permit CA0056227.

Data Reference:

Data from the Donald C. Tillman Water Reclamation Plant NPDES Permit no. CA0056227, Jan 2006-May 2010

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, animal, or aquatic life.

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. The t-test is used to determine if there is a statistically significant decrease in organism response in the sample as compared to the control.

Guideline Reference:

Short-term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms. Fourth Edition. Office of Water, U.S. Environmental Protection Agency. Washington, D.C. EPA-821-R-02-013

Spatial Representation:

The samples were collected at Los Angeles River Reach 4 sites R7 and R8.

Temporal Representation:

The samples were collected from 2006-2010.

Environmental Conditions:

QAPP Information:

QAPP Information Reference(s):


DECISION ID	77439	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Nutrients (Algae)
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Nonpoint Source \| Point Source
TMDL Name:	Los Angeles River Nitrogen (11)
TMDL Project Code:	229
Date TMDL Approved by USEPA:	03/18/2004
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for listing under section 2.2 of the Listing Policy. Under this section of the Policy, a minimum of one line of evidence is needed to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. A TMDL has been developed and approved by USEPA and an approved implementation plan is expected to result in attainment of the standard. The Los Angeles River Nitrogen TMDL was approved by RWQCB on August 19, 2003 and subsequently approved by USEPA on March 18, 2004. This TMDL will address this water body condition. 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 in the Water Quality Limited Segments Being Addressed portion of the section 303(d) list.

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 77439, Nutrients (Algae)	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2517

Pollutant:

Nutrients

LOE Subgroup:

Pollutant-Water

Matrix:

Not Specified

Fraction:

None

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 2006 303(d)

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 Missing

QAPP Information Reference(s):


DECISION ID	68053	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

Pollutant:	Trash
Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (being addressed by USEPA approved TMDL)(2016)
Revision Status	Original
Sources:	Nonpoint Source \| Surface Runoff \| Urban Runoff/Storm Sewers
TMDL Name:	Los Angeles River Trash (12)
TMDL Project Code:	365
Date TMDL Approved by USEPA:	07/24/2008
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal on the section 303(d) list under sections 2.2 of the Listing Policy. Under 2.2 of the Policy, a minimum of one line of evidence is needed to assess listing status. Two lines of evidence are 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 removing this water segment-pollutant combination from the section 303(d) list. There is sufficient justification to place it in the Being Addressed portion of the 303(d) list because a TMDL has been completed and adopted by the Los Angeles RWQCB and approved by USEPA, and is expected to result in attainment of the standard.

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 68053, Trash	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

28080

Pollutant:

Trash

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

A TMDL has been approved for this water segment-pollutant combination. The Trash TMDL for the Los Angeles River Watershed was adopted by the Los Angeles RWQCB on August 09, 2007 and subsequently approved by USEPA. The TMDL was been integrated into the Basin Plan as Attachment A of Regional Board Resolution No. 2007-012.

Data Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Temporal Representation:

Environmental Conditions:

QAPP Information:

QA information unavailable.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 68053, Trash	Region 4
Los Angeles River Reach 4 (Sepulveda Dr. to Sepulveda Dam)

LOE ID:

2516

Pollutant:

Trash

LOE Subgroup:

Narrative Description Data

Matrix:

Not Specified

Fraction:

None

Beneficial Use:

Warm Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Not Specified

Data Used to Assess Water Quality:

The Los Angeles River Trash TMDL was completed by the Regional Board on September 19, 2001 (USEPA, 2002) to address impairments caused by trash. However, on July 19, 2006 the State Board rescinded approval of this TMDL and remanded it back to the Regional Board based on court ruling City of Arcadia v. State Water Resources Control Board (D043877).

Data Reference:

Placeholder reference 2006 303(d)

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 Missing

QAPP Information Reference(s):