Final California 2010 Integrated Report (303(d) List/305(b) Report)

Supporting Information

Regional Board 4 - Los Angeles Region

Water Body Name:	Lake Calabasas
Water Body ID:	CAL4052100019990203084034
Water Body Type:	Lake & Reservoir


DECISION ID	7032	Region 4
Lake Calabasas

Pollutant:	DDT (tissue)
Final Listing Decision:	Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2006)
Revision Status	Revised
Reason for Delisting:	Flaws in original listing
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	This pollutant is being considered for removal from the section 303(d) list under section 4.1 of the Listing Policy. Under this section 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. Line of evidence (LOE) 4137 is a placeholder LOE for a decision made prior to 2006. LOE 28192 contains the original listing data that is not listed in LOE 4137. As such, LOE 4137 has been disassociated from the decision. The original listing for DDT in tissue is based on data collected through the Toxic Substance Monitoring Program and used maximum tissue residue level (MTRL) guidelines rather than a valid assessment guideline (i.e., OEHHA guidelines). Based on the readily available data and information, the weight of evidence indicates that there is sufficient justification for removing this water segment-pollutant combination from the section 303(d) list. This conclusion is based on the staff findings that: 1. The data used satisfies the data quality requirements of section 6.1.4 of the Policy. 2. The data used satisfies the data quantity requirements of section 6.1.5 of the Policy. 3. Zero of two samples exceeded the more appropriate OEHHA fish tissue screening values for DDT and this does not exceed the allowable frequency listed in Table 4.1 of the Listing Policy. 4. Pursuant to section 4.11 of the Listing Policy, no additional data and information are available indicating that standards are not met.

Regional Board Decision Recommendation:	After review of the available data and information, RWQCB staff concludes that the water body-pollutant combination should be removed from the section 303(d) list because applicable water quality standards for the pollutant are not being exceeded and the original listing was faulty.

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 7032, DDT (tissue)	Region 4
Lake Calabasas

LOE ID:

28192

Pollutant:

DDT (Dichlorodiphenyltrichloroethane)

LOE Subgroup:

Pollutant-Tissue

Matrix:

Tissue

Fraction:

Not Recorded

Beneficial Use:

Commercial or recreational collection of fish, shellfish, or organisms

Number of Samples:

Number of Exceedances:

Data and Information Type:

Fish tissue analysis

Data Used to Assess Water Quality:

Zero of two samples exceeded the OEHHA screening value for DDT. Two fish tissue samples, of Large Mouth Bass, were taken as part of State Water Resources Control Board's Toxic Substance Monitoring Program.

Data Reference:

Toxic Substances Monitoring Program data for years 1992-2002 and Coastal Fish Contamination Program for years 1 and 2. State Water Resources Control Board

Toxic Substances Monitoring Program 1991 Data Report. State Water Resources Control Board

SWAMP Data:

Non-SWAMP

Water Quality Objective/Criterion:

The Basin Plan states that, "[t]oxic pollutants shall not be present at levels that will bioaccumulate in aquatic life to levels which are harmful to aquatic life or human health."

Objective/Criterion Reference:

Water Quality Control Plan Los Angeles Region R4 Basin Plan

Evaluation Guideline:

OEHHA lists a fish screening value of 100 ug/kg for total DDT to protect the consumption of fish and shellfish.

Guideline Reference:

Prevalence of Selected Target Chemical Contaminants in Sport Fish From Two California Lakes: Public health designed screening study. Sacramento, CA: Office of Environmental Health Hazard Assessment

Spatial Representation:

Fish samples were collected at sampling station 405.21.03, located at Park Serranto off Park Grenada in Calabasas (Lat: 34 deg 09'10", Long: 118 deg 38'20").

Temporal Representation:

Two tissue samples were collected on 04/20/1991 and on 04/22/1992.

Environmental Conditions:

QAPP Information:

QA Info. not available.

QAPP Information Reference(s):


DECISION ID	7034	Region 4
Lake Calabasas

Pollutant:	Odor
Final Listing Decision:	Do Not Delist from 303(d) list (TMDL required list)
Last Listing Cycle's Final Listing Decision:	List on 303(d) list (TMDL required list)(2006)
Revision Status	Original
Sources:	Nonpoint Source
Expected TMDL Completion Date:	2019
Impairment from Pollutant or Pollution:	Pollutant

Regional Board Conclusion:	303(d) listing decisions made prior to 2006 were not held in an assessment database. The Regional Boards will update this decision when new data and information become available and are assessed.

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):	USEPA approved the listing of this water body as a water quality limited segment requiring a TMDL for this pollutant.

Line of Evidence (LOE) for Decision ID 7034, Odor	Region 4
Lake Calabasas

LOE ID:

4139

Pollutant:

Odor

LOE Subgroup:

Pollutant-Water

Matrix:

Water