Cal. Code Regs. tit. 23 § 3939.32
On October 4, 2007, the Los Angeles Regional Water Quality Control Board (Los Angeles Water Board) adopted Resolution No. R4-2007-016, amending the Water Quality Control Plan for the Los Angeles Region (Basin Plan). This Basin Plan amendment establishes a Total Maximum Daily Load (TMDL) in the Calleguas Creek Watershed for boron, chloride, sulfate, and TDS (Total Dissolved Solids), constituents commonly referred to as salts. The TMDL:
This TMDL addresses water quality impairments due to elevated levels of salts including boron, chloride, sulfate, and TDS in the Calleguas Creek Watershed as documented in the State of California 303(d) list of impaired water bodies. This TMDL supersedes the chloride TMDL established by the U.S. Environmental Protection Agency in 2002.
This TMDL sets forth waste load allocations for POTWs, permitted storm water dischargers, and other NPDES dischargers, and load allocations for irrigated agricultural dischargers which limit the mass of salts that can be discharged to the Calleguas Creek Watershed. The TMDL includes provisions for optional Special Studies to improve understanding of key aspects related to the achievement of waste load allocations and load allocations for salts. The TMDL establishes a Monitoring Plan for tracking inputs and outputs to the Calleguas Creek Watershed to ensure that the goal of a salts balance in the watershed is being achieved and water quality objectives are being met. The TMDL establishes an Implementation Plan that has four key structural elements to the regional implementation: Regional Salinity Management Conveyance (RSMC), Water Conservation, Water Softeners, and Best Management Practices for Irrigated Agriculture. Subwatershed implementation includes the Renewable Water Resource Management Program (RWRMP) for the Southern Reaches and the Northern Reach Renewable Water Management Plan (NRRWMP).
The TMDL implementation plan is based on construction of a regional brine line and ocean outfall whereby brines from the advanced treatment of degraded groundwater in the Calleguas Creek Watershed are discharged directly to the ocean in compliance with the California Ocean Plan. The TMDL implementation plan also includes increased use of POTW effluent and advanced treated (reverse osmosis) groundwater for recycled water. The proposed TMDL requires the POTWs, permitted storm water dischargers, other NPDES dischargers, and irrigated agricultural dischargers to achieve their allocations in the entire watershed within 15 years. The implementation plan has been developed as a phased plan with interim salt load reduction, to allow for a review of implemented actions to attain water quality.
Cal. Code Regs. Tit. 23, § 3939.32