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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Clark Channel
Water Body ID:	CAR4051500020210324044688
Water Body Type:	River & Stream


DECISION ID	140093	Region 4
Clark Channel

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 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

251910

Pollutant:

Alkalinity as CaCO3

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 Clark Channel to determine beneficial use support and results are as follows: 1 of 1 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:

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 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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

251825

Pollutant:

Alkalinity as CaCO3

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 LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

251870

Pollutant:

Alkalinity as CaCO3

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 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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

256472

Pollutant:

Alkalinity as CaCO3

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 Prop 84-Los Cerrritos Channel Low Impact Dev. data for Clark Channel 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 California Environmental Data Exchange Network 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: LCCLID_ClarkHartwell (LCC LID Clark Channel at Hartwell Park).

Temporal Representation:

The samples were collected between the dates of 2014-08-21 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

251869

Pollutant:

Alkalinity as CaCO3

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:

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

256471

Pollutant:

Alkalinity as CaCO3

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:

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_ClarkCivic (LCC LID Clark Channel at Lakewood Civic Center).

Temporal Representation:

The samples were collected between the dates of 2014-08-21 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140093, Alkalinity as CaCO3	Region 4
Clark Channel

LOE ID:

256473

Pollutant:

Alkalinity as CaCO3

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:

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_DelAmoClark (LCC LID Del Amo Channel at Clark Ave).

Temporal Representation:

The samples were collected between the dates of 2014-08-21 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed


DECISION ID	140085	Region 4
Clark Channel

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

Regional Board Conclusion:	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 140085, Cadmium	Region 4
Clark Channel

LOE ID:

251902

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:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Cadmium. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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 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:

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: LCC-SB8 (Clark).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-11-28 to 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140086	Region 4
Clark Channel

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:	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 140086, Chloride	Region 4
Clark Channel

LOE ID:

251987

Pollutant:

Chloride

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold 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:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The chloride criterion continuous concentration (expressed as a 4-day average) to protect aquatic life in freshwater is 230000 ug/L (230 mg/L)(USEPA National Recommended Water Quality Criteria, 2006).

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140086, Chloride	Region 4
Clark Channel

LOE ID:

251708

Pollutant:

Chloride

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold 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:

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140094	Region 4
Clark Channel

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

Regional Board Conclusion:	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 140094, Chromium	Region 4
Clark Channel

LOE ID:

251839

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:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140094, Chromium	Region 4
Clark Channel

LOE ID:

251860

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:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Chromium.

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140088	Region 4
Clark Channel

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 140088, Iron	Region 4
Clark Channel

LOE ID:

252484

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:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Iron.

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140088, Iron	Region 4
Clark Channel

LOE ID:

252023

Pollutant:

Iron

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 LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Iron.

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140088, Iron	Region 4
Clark Channel

LOE ID:

252443

Pollutant:

Iron

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 LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Iron.

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140088, Iron	Region 4
Clark Channel

LOE ID:

252501

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:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Iron.

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140089	Region 4
Clark Channel

Pollutant:	Lead
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 140089, Lead	Region 4
Clark Channel

LOE ID:

263032

Pollutant:

Lead

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 Prop 84-Los Cerrritos Channel Low Impact Dev. data for Clark Channel to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Lead.

Data Reference:

WQ data from the California Environmental Data Exchange Network assembled for the 2024 Integrated Report in Region 4.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The dissolved lead 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 2.5 ug/L (California Toxics Rule, 2000).

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LCCLID_DelAmoClark (LCC LID Del Amo Channel at Clark Ave).

Temporal Representation:

The samples were collected between the dates of 2014-07-23 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140089, Lead	Region 4
Clark Channel

LOE ID:

252390

Pollutant:

Lead

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 Clark Channel to determine beneficial use support, and the results are as follows: 0 of the 0 samples exceeded the evaluation guideline for Lead. Although a total of 1 samples were collected, 1 of these samples were not included in the assessment because the laboratory data reporting limit(s) was above the water quality threshold and therefore the results could not be quantified with the level of certainty required by the Listing Policy Section 6.1.5.5.

Data Reference:

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: LCC-SB8 (Clark).

Temporal Representation:

Data for this waterbody were collected over the date range 2019-11-28 to 2019-11-28

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 140089, Lead	Region 4
Clark Channel

LOE ID:

263096

Pollutant:

Lead

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 Environmental Data Exchange Network 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: LCCLID_ClarkCivic (LCC LID Clark Channel at Lakewood Civic Center).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140089, Lead	Region 4
Clark Channel

LOE ID:

262921

Pollutant:

Lead

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 Environmental Data Exchange Network 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: LCCLID_ClarkHartwell (LCC LID Clark Channel at Hartwell Park).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed


DECISION ID	149510	Region 4
Clark Channel

Pollutant:	Mercury
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 17 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 149510, Mercury	Region 4
Clark Channel

LOE ID:

252638

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 8 samples exceeded the water quality threshold for Mercury.

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 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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2018-02-20 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 149510, Mercury	Region 4
Clark Channel

LOE ID:

252620

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:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 0 of 9 samples exceeded the water quality threshold for Mercury.

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 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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2017-02-17 and 2019-12-04

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140090	Region 4
Clark Channel

Pollutant:	Nickel
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 140090, Nickel	Region 4
Clark Channel

LOE ID:

252624

Pollutant:

Nickel

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140090, Nickel	Region 4
Clark Channel

LOE ID:

252644

Pollutant:

Nickel

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 samples exceeded the water quality threshold for Nickel.

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	149509	Region 4
Clark Channel

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:	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 149509, Nitrogen, Nitrate	Region 4
Clark Channel

LOE ID:

302493

Pollutant:

Nitrogen, Nitrate

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140092	Region 4
Clark Channel

Pollutant:	Zinc
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 140092, Zinc	Region 4
Clark Channel

LOE ID:

268355

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:

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_DelAmoClark (LCC LID Del Amo Channel at Clark Ave).

Temporal Representation:

The samples were collected between the dates of 2014-07-23 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140092, Zinc	Region 4
Clark Channel

LOE ID:

268340

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:

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_ClarkHartwell (LCC LID Clark Channel at Hartwell Park).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140092, Zinc	Region 4
Clark Channel

LOE ID:

252970

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 Clark Channel to determine beneficial use support and results are as follows: 1 of 1 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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140092, Zinc	Region 4
Clark Channel

LOE ID:

252966

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 Clark Channel to determine beneficial use support and results are as follows: 0 of 1 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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140092, Zinc	Region 4
Clark Channel

LOE ID:

268409

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:

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_ClarkCivic (LCC LID Clark Channel at Lakewood Civic Center).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed


DECISION ID	153962	Region 4
Clark Channel

Pollutant:	Aluminum
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
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. 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. 4 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 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. 0 of 2 and 2 of 2 samples exceed the criteria listed in the evaluation guideline in water and this exceeds the allowable frequency listed in Table 3.1 of the Listing Policy for warm freshwater habitat. 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 153962, Aluminum	Region 4
Clark Channel

LOE ID:

314907

Pollutant:

Aluminum

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 LA County MS4 data for Clark Channel 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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 153962, Aluminum	Region 4
Clark Channel

LOE ID:

314685

Pollutant:

Aluminum

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 Clark Channel to determine beneficial use support and results are as follows: 0 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:

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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 153962, Aluminum	Region 4
Clark Channel

LOE ID:

314891

Pollutant:

Aluminum

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 LA County MS4 data for Clark Channel 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:

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 153962, Aluminum	Region 4
Clark Channel

LOE ID:

314904

Pollutant:

Aluminum

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 Clark Channel to determine beneficial use support and results are as follows: 0 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:

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140087	Region 4
Clark Channel

Pollutant:	Copper
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
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 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. 3 of 11 samples exceed the criteria 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 140087, Copper	Region 4
Clark Channel

LOE ID:

251670

Pollutant:

Copper

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 Clark Channel to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Copper.

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

Objective/Criterion Reference:

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

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 140087, Copper	Region 4
Clark Channel

LOE ID:

259092

Pollutant:

Copper

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 Environmental Data Exchange Network 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: LCCLID_DelAmoClark (LCC LID Del Amo Channel at Clark Ave).

Temporal Representation:

The samples were collected between the dates of 2014-07-23 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140087, Copper	Region 4
Clark Channel

LOE ID:

258894

Pollutant:

Copper

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 Prop 84-Los Cerrritos Channel Low Impact Dev. data for Clark Channel to determine beneficial use support and results are as follows: 1 of 3 samples exceeded the water quality threshold for Copper.

Data Reference:

WQ data from the California Environmental Data Exchange Network 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: LCCLID_ClarkHartwell (LCC LID Clark Channel at Hartwell Park).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140087, Copper	Region 4
Clark Channel

LOE ID:

259093

Pollutant:

Copper

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 Environmental Data Exchange Network 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: LCCLID_ClarkCivic (LCC LID Clark Channel at Lakewood Civic Center).

Temporal Representation:

The samples were collected between the dates of 2014-07-24 and 2014-09-04

Environmental Conditions:

QAPP Information:

Kinnetic Laboratories, Inc.. 2020. Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed.

QAPP Information Reference(s):

Implementation of the Coordinated Integrated Monitoring Plan (CIMP) for the Los Cerritos Channel Watershed

Line of Evidence (LOE) for Decision ID 140087, Copper	Region 4
Clark Channel

LOE ID:

252239

Pollutant:

Copper

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 Clark Channel to determine beneficial use support and results are as follows: 1 of 1 samples exceeded the water quality threshold for Copper.

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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2019-11-28 and 2019-11-28

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	150797	Region 4
Clark Channel

Pollutant:	Indicator Bacteria
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
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 3.3 of the Listing Policy. Under section 3.2 a single line of evidence is necessary to assess listing status. One line of evidence is available in the administrative record to assess this pollutant. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification in favor of placing this water segment-pollutant combination on the 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. 13 of 13 samples exceed the statistical threshold value for E. coli and this exceeds the allowable frequency listed in Table 3.2 of the Listing Policy. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are 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 150797, Indicator Bacteria	Region 4
Clark Channel

LOE ID:

303156

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 Clark Channel to determine beneficial use support and the results are as follows: 7 of the 7 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): LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the days of 2018-01-09 and 2019-12-04 .

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 150797, Indicator Bacteria	Region 4
Clark Channel

LOE ID:

303183

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 Clark Channel to determine beneficial use support and the results are as follows: 6 of the 6 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): LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the days of 2018-01-09 and 2019-12-04 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	140091	Region 4
Clark Channel

Pollutant:	Oil and Grease
Final Listing Decision:	List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	New Decision
Revision Status	Revised
Sources:	A Source Unknown
Expected TMDL Completion Date:	2037
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 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. 15 of 15 samples exceed the criteria 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 140091, Oil and Grease	Region 4
Clark Channel

LOE ID:

252796

Pollutant:

Oil and Grease

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 LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 8 of 8 samples exceeded the water quality threshold for OilandGrease; HEM.

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 not contain oils, greases, waxes or other materials in concentrations that result in a visible film or coating on the surface of the water or on objects in the water, that cause nuisance, or that otherwise adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

According to the USEPA Quality Criteria for Water (Gold Book), concentrations of oil at 0.001 mg/L can harm aquatic life. (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: LCC-SB9 (Del Amo).

Temporal Representation:

The samples were collected between the dates of 2017-02-17 and 2019-12-04

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 140091, Oil and Grease	Region 4
Clark Channel

LOE ID:

252795

Pollutant:

Oil and Grease

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 LA County MS4 data for Clark Channel to determine beneficial use support and results are as follows: 7 of 7 samples exceeded the water quality threshold for OilandGrease; HEM.

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:

According to the USEPA Quality Criteria for Water (Gold Book), concentrations of oil at 0.001 mg/L can harm aquatic life. (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: LCC-SB8 (Clark).

Temporal Representation:

The samples were collected between the dates of 2018-02-20 and 2019-12-20

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)