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

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Cold Creek (Los Angeles County)
Water Body ID:	CAR4042100020020130153315
Water Body Type:	River & Stream


DECISION ID	137551	Region 4
Cold Creek (Los Angeles County)

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 137551, Alkalinity as CaCO3	Region 4
Cold Creek (Los Angeles County)

LOE ID:

256486

Pollutant:

Alkalinity as CaCO3

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed SWAMP RWB4 Monitoring data for Cold Creek (Los Angeles County) 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:

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

SWAMP Data:

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: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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	137546	Region 4
Cold Creek (Los Angeles County)

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:	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 137546, Nitrate/Nitrite (Nitrite + Nitrate as N)	Region 4
Cold Creek (Los Angeles County)

LOE ID:

243936

Pollutant:

Nitrate/Nitrite (Nitrite + Nitrate as N)

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Municipal & Domestic Supply

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 3 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 Cold Creek (Los Angeles County) of 10 (mg/L).

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station MCW-CIMP 5 (34.078983, -118.699933), located in Cold Creek between Crater Camp Drive and Live Oak Circle Drive..

Temporal Representation:

The water samples were taken between 1/5/2019 - 1/31/2019, 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)


DECISION ID	149511	Region 4
Cold Creek (Los Angeles County)

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 149511, Nitrogen, Nitrate	Region 4
Cold Creek (Los Angeles County)

LOE ID:

302503

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold 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 Cold Creek (Los Angeles County) to determine beneficial use support and results are as follows: 0 of 2 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: MCW-CIMP 5 (Cold Creek between Crater Camp Drive and Live Oak Circle Drive.).

Temporal Representation:

The samples were collected between the dates of 2016-12-16 and 2019-01-12

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 149511, Nitrogen, Nitrate	Region 4
Cold Creek (Los Angeles County)

LOE ID:

302366

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold 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 Water Quality Monitoring in the Malibu Creek Water data for Cold Creek (Los Angeles County) to determine beneficial use support and results are as follows: 0 of 3 samples exceeded the water quality threshold for Nitrate as N.

Data Reference:

Field, Habitat 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 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: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 149511, Nitrogen, Nitrate	Region 4
Cold Creek (Los Angeles County)

LOE ID:

302548

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold 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 Cold Creek (Los Angeles County) 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: MCW-CIMP 5 (Cold Creek between Crater Camp Drive and Live Oak Circle Drive.).

Temporal Representation:

The samples were collected between the dates of 2019-01-31 and 2019-01-31

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 149511, Nitrogen, Nitrate	Region 4
Cold Creek (Los Angeles County)

LOE ID:

302477

Pollutant:

Nitrogen, Nitrate

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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 (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: MCW-CIMP 5 (Cold Creek between Crater Camp Drive and Live Oak Circle Drive.).

Temporal Representation:

The samples were collected between the dates of 2019-01-05 and 2019-01-05

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	151869	Region 4
Cold Creek (Los Angeles County)

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:	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 151869, Oxygen, Dissolved	Region 4
Cold Creek (Los Angeles County)

LOE ID:

308257

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

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 both COLD and SPWN shall not be depressed below 7 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: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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 151869, Oxygen, Dissolved	Region 4
Cold Creek (Los Angeles County)

LOE ID:

308195

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

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 COLD shall not be depressed below 6 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: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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 151869, Oxygen, Dissolved	Region 4
Cold Creek (Los Angeles County)

LOE ID:

308308

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Water Board staff assessed Water Quality Monitoring in the Malibu Creek Water data for Cold Creek (Los Angeles County) to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat 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:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 151869, Oxygen, Dissolved	Region 4
Cold Creek (Los Angeles County)

LOE ID:

307968

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold 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 Water Quality Monitoring in the Malibu Creek Water data for Cold Creek (Los Angeles County) to determine beneficial use support and results are as follows: 2 of 3 samples exceeded the water quality threshold for Oxygen, Dissolved.

Data Reference:

Field, Habitat 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:

Guideline Reference:

Spatial Representation:

The samples were collected at 1 monitoring site: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 151869, Oxygen, Dissolved	Region 4
Cold Creek (Los Angeles County)

LOE ID:

83704

Pollutant:

Oxygen, Dissolved

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 9 minimums of Dissolved Oxygen concentrations had no exceedences.

Data Reference:

Data for Metals, Nuisance, Nutrients, Other Inorganics, and Salinity in Various Region 4 Water Bodies, 2006-2010.

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 5 mg/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 J_LCOLDCRK and J_UCOLDCRK stations.

Temporal Representation:

Samples were collected approximately twice a year from August 2006 to November 2008.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):


DECISION ID	137548	Region 4
Cold Creek (Los Angeles County)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 137548, Temperature, water	Region 4
Cold Creek (Los Angeles County)

LOE ID:

267162

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat 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 Water Quality Control Plan for the Los Angeles Region states that: The natural receiving water temperature of all regional waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Board that such alteration in temperature does not adversely affect beneficial uses.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 137548, Temperature, water	Region 4
Cold Creek (Los Angeles County)

LOE ID:

267228

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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 137548, Temperature, water	Region 4
Cold Creek (Los Angeles County)

LOE ID:

267019

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Fish Spawning

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat 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:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 137548, Temperature, water	Region 4
Cold Creek (Los Angeles County)

LOE ID:

267138

Pollutant:

Temperature, water

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Inland Fishes of California (Moyle 1976) states that for rainbow trout the optimum range for growth and completion of most life stages is 13-21 degrees C (page 129).

Guideline Reference:

Inland Fishes of California

Spatial Representation:

The samples were collected at 1 monitoring site: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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	137549	Region 4
Cold Creek (Los Angeles County)

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:	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 137549, Total Dissolved Solids	Region 4
Cold Creek (Los Angeles County)

LOE ID:

244081

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

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 Tapia Water Reclamation Facility to determine beneficial use support. The results are as follows: Zero out of one samples exceed the criterion for Total Dissolved Solids.

Data Reference:

Field, Habitat 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 Water Quality Control Plan for the Los Angeles Region lists a site specific objective for Total Dissolved Solids in West Fork Cold Creek of 2000 mg/L

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station WQ_CCP (34.0973553, -118.6578959), located in Cold Creek (Los Angeles County).

Temporal Representation:

Water samples were taken on 4/24/2018 for the Water Quality Monitoring in the Malibu Creek Water.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the quality control and quality assurance provisions of the Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 137549, Total Dissolved Solids	Region 4
Cold Creek (Los Angeles County)

LOE ID:

244080

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat 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 Water Quality Control Plan for the Los Angeles Region lists a site specific objective for Total Dissolved Solids in West Fork Cold Creek of 2000 mg/L

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station WQ_CCP (34.0973553, -118.6578959), located in Cold Creek (Los Angeles County).

Temporal Representation:

Water samples were taken on 3/28/2018 for the Water Quality Monitoring in the Malibu Creek Water.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the quality control and quality assurance provisions of the Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 137549, Total Dissolved Solids	Region 4
Cold Creek (Los Angeles County)

LOE ID:

244079

Pollutant:

Total Dissolved Solids

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat 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 Water Quality Control Plan for the Los Angeles Region lists a site specific objective for Total Dissolved Solids in West Fork Cold Creek of 2000 mg/L

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

Station WQ_CCP (34.0973553, -118.6578959), located in Cold Creek (Los Angeles County).

Temporal Representation:

Water samples were taken on 1/19/2018 for the Water Quality Monitoring in the Malibu Creek Water.

Environmental Conditions:

QAPP Information:

The work was performed in accordance with the quality control and quality assurance provisions of the Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed


DECISION ID	137550	Region 4
Cold Creek (Los Angeles County)

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

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

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

State Board Review of Regional Board Conclusion and Recommendation:

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

Line of Evidence (LOE) for Decision ID 137550, Turbidity	Region 4
Cold Creek (Los Angeles County)

LOE ID:

268224

Pollutant:

Turbidity

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Total

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

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 25 NTU or greater can cause a reduction in juvenile salmonid growth due to interference with their ability to find food (Sigler et al. 1984).

Guideline Reference:

Effects of chronic turbidity on density and growth of steelheads and coho salmon. Transactions of the American Fisheries Society 113:142-150

Spatial Representation:

The samples were collected at 1 monitoring site: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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	137547	Region 4
Cold Creek (Los Angeles County)

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:	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 137547, pH	Region 4
Cold Creek (Los Angeles County)

LOE ID:

265092

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

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

SWAMP Data:

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: 404R4S016 (Cold Creek upstream Cold Canyon Rd.).

Temporal Representation:

The samples were collected between the dates of 2020-07-15 and 2020-07-15

Environmental Conditions:

QAPP Information:

SWRCB. 2018. This is a placeholder reference for data that was collected after QAPP requirements were developed, but exempt from the requirements.

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 137547, pH	Region 4
Cold Creek (Los Angeles County)

LOE ID:

265302

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Data Reference:

Field, Habitat 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:

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: WQ_CCP (Cold Creek Preserve).

Temporal Representation:

The samples were collected between the dates of 2018-01-29 and 2018-04-24

Environmental Conditions:

QAPP Information:

Los Angeles Regional Water Quality Control Board. 2016. Coordinated Integrated Monitoring Program for Malibu Creek Watershed.

QAPP Information Reference(s):

Coordinated Integrated Monitoring Program for Malibu Creek Watershed

Line of Evidence (LOE) for Decision ID 137547, pH	Region 4
Cold Creek (Los Angeles County)

LOE ID:

83705

Pollutant:

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Dissolved

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Numeric data generated from 7 minimums and maximums had no exceedences.

Data Reference:

Data for Metals, Nuisance, Nutrients, Other Inorganics, and Salinity in Various Region 4 Water Bodies, 2006-2010.

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 J_LCOLDCRK and J_UCOLDCRK stations.

Temporal Representation:

Samples were collected approximately twice per semi-annual period from August 2006 to November 2008.

Environmental Conditions:

QAPP Information:

NPDES quality assurance.

QAPP Information Reference(s):


DECISION ID	150285	Region 4
Cold Creek (Los Angeles County)

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 3.2 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 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. 25 of 51 samples exceeded the geometric mean for E. coli and 10 of 21 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:

Line of Evidence (LOE) for Decision ID 150285, Indicator Bacteria	Region 4
Cold Creek (Los Angeles County)

LOE ID:

303082

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 Cold Creek (Los Angeles County) to determine beneficial use support and the results are as follows: 25 of the 51 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): MCW-CIMP 5 (Cold Creek between Crater Camp Drive and Live Oak Circle Drive.).

Temporal Representation:

The samples were collected between the days of 2016-12-27 and 2019-06-25 .

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 150285, Indicator Bacteria	Region 4
Cold Creek (Los Angeles County)

LOE ID:

303185

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 Cold Creek (Los Angeles County) to determine beneficial use support and the results are as follows: 10 of the 21 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): MCW-CIMP 5 (Cold Creek between Crater Camp Drive and Live Oak Circle Drive.).

Temporal Representation:

The samples were collected between the days of 2016-12-27 and 2019-06-25 .

Environmental Conditions:

QAPP Information:

Municipal Separate Storm Sewer System (MS4)

QAPP Information Reference(s):

Municipal Separate Storm Sewer System (MS4)


DECISION ID	98334	Region 4
Cold Creek (Los Angeles County)

Pollutant:	Benthic Community Effects
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:	Benthic Community Effects is being considered for placement on the CWA section 303(d) List under sections 3.9 of the Listing Policy. Under section 3.9, an additional line of evidence associating the Benthic Community Effects with a water or sediment concentration of pollutants is necessary to assess listing status. Two of the seven samples collected had IBI scores below 40 but there are no impairments for associated pollutant. 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 water 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. Two of the seven samples collected had IBI scores below 40 however, as required under section 3.9 of the Listing Policy, pollutant(s) could not be directly associated with the Benthic Community Effects. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met. The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).

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:	The CSCI is applicable statewide, accounts for a much wider range of natural variability, and provides equivalent scoring thresholds in all regions of the state. The CSCI will be used in the future for water quality assessment purposes statewide over the regional indices of biologic integrity (IBIs).

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 98334, Benthic Community Effects	Region 4
Cold Creek (Los Angeles County)

LOE ID:

83700

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Two of the seven samples collected had IBI scores below 40. The samples were collected at three different sites. The scores were, 47 (fall 2006) and 59 (spring 2009) for site CC11; 31 (fall 2006) and 27 (spring 2009) for site CC2; and 73 (fall 2006), 74 (spring 2008) and 79 (spring 2009) for site CC3.

Data Reference:

Data for abundance calculations, taxa list and IBI scores in Malibu Creek Watershed, 2006-2009.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

All waters shall be maintained free of toxic substances in concentrations that are toxic to, or that produce detrimental physiological responses in, human, plant or animal, or aquatic life. Compliance with this objective will be determined by use of indicator organisms, analysis of species diversity, population density, growth anomalies, bioassays of appropriate duration or other appropriate methods as specified by the State or Regional Board. Region 4 Basin Plan.

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

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

Guideline Reference:

Revised approach to toxicity test acceptability criteria using a statistical performance assessment. Environmental Toxicology and Chemistry, vol. 16, No. 6, pp 1322¿1329

Spatial Representation:

Samples were collected at station CC11 Cold Creek Middle. Cold Canyon Road, CC2 Cold Creek, Piuma Rd. at the Backbone Trail, and CC3 Cold Creek, Stunt Rd. at Cold Creek Preserve.

Temporal Representation:

The samples were collected in the fall 2006, and the spring of 2008 and 2009.

Environmental Conditions:

QAPP Information:

Data was collected in compliance with California Stream Bioassessment Procedure. Collection procedures were audited by California Department of Fish and Game in 2006.

QAPP Information Reference(s):

Line of Evidence (LOE) for Decision ID 98334, Benthic Community Effects	Region 4
Cold Creek (Los Angeles County)

LOE ID:

83703

Pollutant:

Benthic-Macroinvertebrate Bioassessments

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Three samples were collected from Cold Creek over three years. The three samples collected had IBI scores above 40. The scores were 53 (2006), 52 (2007), and 55 (2008).

Data Reference:

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

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:

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

Spatial Representation:

The samples were collected from Cold Creek station number 17.

Temporal Representation:

The samples were collected in 2006, 2007 and 2008.

Environmental Conditions:

QAPP Information:

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

QAPP Information Reference(s):


DECISION ID	76871	Region 4
Cold Creek (Los Angeles County)

Pollutant:	Invasive Species
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:	Pollution

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.10 of the Listing Policy. Under section 3.10, waters are listed when a declining trend in water quality is substantiated. Two lines of evidence are available in the administrative record to assess this pollutant. Zero of 2 sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and 0 out of 4 sites sampled showed medium or high densities of mud snail in 2008. One site exhibited a low density of mudsnails in 2008. At high numbers, mud snails can completely cover a stream bed and damage local stream ecosystems. The colonies outcompete native aquatic invertebrates that the watershed¿s fish and amphibians rely on for food, disrupting the entire food web. In Cold Creek the mudsnails have not reached high densities. Benthic macroinvertebrates as measured by Southern California IBI (index of biological integrity) in Cold Creek were poor or good in 2005 indicating impairment of benthic community structure. Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification against placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Data was collected over a three years time frame and a baseline condition of zero abundance of the invasive species was used. 3. Zero of two sites showed an increase in density of mud snails over a three years of sampling and zero of four sites sampled showed medium or high densities of mud snail in 2008. 4. Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. 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 76871, Invasive Species	Region 4
Cold Creek (Los Angeles County)

LOE ID:

30173

Pollutant:

Invasive Species

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning | Preservation of Rare & Endangered Species | Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

Two sites sampled in 2005 IBI scores were calculated at 27, category ¿poor¿ and 60, category ¿good¿

Data Reference:

Malibu Bioassessment Winter 2005

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

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

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

The IBI is a multi-metric assessment that employs biological metrics that respond to a habitat or water quality impairment. Each of the biological metrics measured at a site are converted to an IBI score then summed. These cumulative scores are then ranked as very good (80-100), good (60-79), fair (40-49), poor (20-39) and very poor (0-19) habitat conditions. Sites with scores below 39 are considered to have impaired conditions.

Guideline Reference:

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

Spatial Representation:

Two sites in Cold Creek were sampled, CC2 and CC3.

Temporal Representation:

Sites were sampled in winter of 2005.

Environmental Conditions:

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

QAPP Information:

Data was collected in compliance with California Stream Bioassessment Procedure. Collection procedures were audited by California Department of Fish and Game in 2006.

QAPP Information Reference(s):

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

QAPP Information Reference(s):

California Stream Bioassessment Procedure Biological and Physical Habitat Field Audit

Line of Evidence (LOE) for Decision ID 76871, Invasive Species	Region 4
Cold Creek (Los Angeles County)

LOE ID:

28707

Pollutant:

Invasive Species

LOE Subgroup:

Population/Community Degradation

Matrix:

Water

Fraction:

None

Beneficial Use:

Cold Freshwater Habitat

Aquatic Life Use:

Fish Spawning | Preservation of Rare & Endangered Species | Wetland Habitat | Wildlife Habitat

Number of Samples:

Number of Exceedances:

Data and Information Type:

Benthic macroinvertebrate surveys

Data Used to Assess Water Quality:

A total of zero of two sites showed an increase in density of mud snails over the three years of sampling (2006, 2007, 2008) and zero of four sites sampled showed medium or high densities of mud snail in 2008.

Data Reference:

New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

Presence of high densities and increasing densities. While quantitative and predictive research continues, due to its ability to attain extremely high densities, the impacts of the mudsnails on aquatic ecosystems where it occurs in the western U.S. are large and include: decreased densities of native macroinvertebrates and reduced food resources; decreased whole-stream algal production; poor food source in that mudsnails are much more difficult to digest, with their hard shells and operculum than are the thin-shelled, native pulmonate snails that do not have opercula or than soft-bodied, aquatic insect larvae.

Guideline Reference:

The New Zealand Mudsnail Invades the Western United States. Aquatic Nuisance Species Digest Volume 4 No. 4.

Spatial Representation:

Four sites were sampled in the following locations in Cold Creek: Stunt Rd. at the lower gated entrance in Cold Creek Reserve; the public access off Stunt Rd. DS of lower entrance; Cold Canyon Rd. M.M. 1.36 Cold Creek Midway D; and Piuma Rd and Crater Camp Rd at the Backbone Trail.

Temporal Representation:

The Stunt Road and Cold Canyon Road sites were sampled in July of 2006, July of 2007 and October of 2008. The other three sites were sampled in July of 2007 and October of 2008.

Environmental Conditions:

QAPP Information:

Data was collected as detailed in the Santa Monica Bay Restoration Commission and Santa Monica Baykeeper New Zealand Mudsnail Surveys.

QAPP Information Reference(s):

New Zealand Mudsnail Surveys July 2006, July 2007 and October 2008 Santa Monica Mountains. Santa Monica Bay Restoration Commission / Santa Monica Baykeeper.


DECISION ID	70914	Region 4
Cold Creek (Los Angeles County)

Pollutant:	Sulfates
Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	Do Not List on 303(d) list (TMDL required list)(2016)
Revision Status	Original
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.2 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. An insufficient total number of samples were taken and an insufficient number of samples exceed the MCL guideline for Sulfate. Based on the readily available data and information, the weight of evidence indicates that there is insufficient justification in favor of placing this water segment-pollutant combination on the section 303(d) list in the Water Quality Limited Segments category. This conclusion is based on the staff findings that: 1.The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2.The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3.Two of two samples exceeded the MCL guidelineand this sample size is insufficient to determine, with the power and confidence of the Listing Policy, the applicable beneficial use support rating. 4.Pursuant to section 3.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	This is a decision previously approved by the State Water Resources Control Board and the USEPA. No new data were assessed by the Regional Board for the current. 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 70914, Sulfates	Region 4
Cold Creek (Los Angeles County)

LOE ID:

2256

Pollutant:

Sulfates

LOE Subgroup:

Pollutant-Water

Matrix:

Water

Fraction:

Not Recorded

Beneficial Use:

Municipal & Domestic Supply

Number of Samples:

Number of Exceedances:

Data and Information Type:

PHYSICAL/CHEMICAL MONITORING

Data Used to Assess Water Quality:

Two of 2 samples exceeding the MCL guideline (SWAMP, 2004).

Data Reference:

Placeholder reference 2006 303(d)

SWAMP Data:

SWAMP

Water Quality Objective/Criterion:

CCR- Title 22 Table 64449-B Secondary Maximum Contaminant Levels for sulfate of 250 mg/l.

Objective/Criterion Reference:

Placeholder reference 2006 303(d)

Evaluation Guideline:

Guideline Reference:

Spatial Representation:

One sampling station at Malibu Creek 34.0429 -118.6842.

Temporal Representation:

Samples were collected March 2003 through March 2004.

Environmental Conditions:

Malibu Creek Watershed: 404.21.

QAPP Information:

SWAMP Quality Assurance Plan.

QAPP Information Reference(s):