Cal. Code Regs. tit. 23 § 3939.17
On July 7, 2005, the Los Angeles Regional Water Quality Control Board adopted Resolution No. R4-2005-010, amending the Water Quality Control Plan for the Los Angeles Region by establishing a Total Maximum Daily Load (TMDL) for organochlorine (OC) pesticides, polychlorinated biphenyls (PCBs), and siltation in Calleguas Creek, its tributaries, and Mugu Lagoon. The TMDL set numeric concentration-based targets for OC pesticides and PCBs in water, sediment, and/or fish tissue to ensure protection of designated beneficial uses. The specific pollutants addressed are aldrin, chlordane, dacthal, dichlorodiphenyldicloroethane (DDD), dichlorodiphenyldicloroethelyene (DDE), dichlorodiphenyltrichloroethane (DDT), dieldrin, endosulfan I, endosulfan II, endrin, hexachlorocyclohexane (alpha, beta, delta, and gamma BHC), heptachlor, heptachlor epoxide, PCBs, and toxaphene.
Water column targets are derived from California Toxics Rule (CTR) water quality chronic criteria for protection of aquatic life. Fish tissue targets are derived from CTR human health criteria for consumption of organisms. Sediment targets are derived from National Oceanographic and Atmospheric Administration sediment quality guidelines for fresh and marine waters. This TMDL further requires an annual reduction in the import of silt of 5,200 tons per year to Mugu Lagoon and preservation of 1,400 acres of existing aquatic habitat in Mugu Lagoon. Targets will be met by limiting discharges from point and nonpoint sources of pollutants.
Interim and final wasteload allocations assigned to point source dischargers will be implemented through National Pollution Discharge Elimination System (NPDES) permits. The TMDL establishes wasteload allocations for five major wastewater treatment plants (Hill Canyon Waste Water Treatment Plant, Simi Valley Water Quality Control Plant, Ventura County (Moorpark) Water Treatment Plant, Camarillo Water Reclamation Plant, and Camrosa Water Reclamation Plant), storm water permittees (California Department of Transportation, general construction, general industrial, and municipal permittees), and to minor point sources.
Interim and final load allocations for nonpoint sources will be implemented through the State's Nonpoint Source Pollution Control Program. Sediment-based load allocations will be measured as an in-stream annual average at the base of each sub-watershed. A Conditional Waiver for Irrigated Lands and/or Agricultural Water Quality Management Plans will be developed to implement load allocations for agricultural dischargers, taking into account TMDL-required studies to assess the effectiveness of Management Practices for reduction of pollutants from agricultural operations.
Special studies and/or monitoring will be conducted as part of this TMDL. The Los Angeles Regional Water Quality Control Board has committed to reconsidering the TMDL, if necessary, based on the collected data or other relevant information. Final wasteload and load allocations must be achieved within 20 years of the effective date of the TMDL.
Cal. Code Regs. Tit. 23, § 3939.17