Final California 2010 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	16623	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:	New Decision
Revision Status	Revised
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for placement on the section 303(d) list under section 3.10 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 watersheds 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:	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:

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 16623, 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:

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:

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.

Line of Evidence (LOE) for Decision ID 16623, 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:

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

California Stream Bioassessment Procedure Biological and Physical Habitat Field Audit


DECISION ID	6796	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)(2006)
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 guideline. More data is needed to determine if the water quality standard is exceeded. 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:	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.

USEPA Action (if applicable):

Line of Evidence (LOE) for Decision ID 6796, 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):