Cal. Code Regs. tit. 23 § 3939.45
On December 6, 2012, the Los Angeles Regional Water Quality Control Board adopted Resolution No. R12-011, amending the Water Quality Control Plan for the Los Angeles Region (Basin Plan) by establishing a Total Maximum Daily Load (TMDL) for Algae, Nutrients, and Eutrophic Conditions in the Ventura River including the Estuary and its Tributaries. The TMDL includes numeric targets for dissolved oxygen and pH equal to their numeric water quality objectives in the Basin Plan. The TMDL also includes numeric targets for algal and phytoplankton biomass and percent cover as numeric interpretations of the water quality condition that will demonstrate attainment of the narrative water quality objective for biostimulatory substances in the Basin Plan. The method to develop these numeric targets is based on the California Nutrient Numeric Endpoints (NNE) approach, developed by U.S. EPA Region 9 and the State and Regional Water Quality Control Boards. The TMDL includes waste load allocations (WLAs) and load allocations (LAs) for discharges from the Ojai Valley Waste Water Treatment Plant (WWTP), the Ventura County Municipal Separate Storm Sewer (MS4), the Caltrans MS4, agriculture sources, horse/intensive livestock activities, grazing activities, general industrial and construction stormwater permittees, onsite wastewater treatment systems, and other National Pollution Discharge Elimination System (NPDES) permittees in the Ventura River watershed in order to attain numeric targets.
The regulatory mechanisms used to implement the WLAs include the Ojai Valley WWTP NPDES permit, the Ventura County MS4 permit, the Caltrans MS4 permit, the general industrial storm water permits, the general construction storm water permits, and other NPDES permits. The regulatory mechanisms used to implement the LAs include Basin Plan discharge prohibitions, waste discharge requirements (WDRs), and waivers of WDRs or other regulatory mechanisms in accordance with the State Nonpoint Source Implementation and Enforcement Policy (NPS Policy). The TMDL allows for an implementation schedule of up to 6-12 years to meet the WLAs and LAs, depending on the source. Discharge monitoring to demonstrate compliance with WLAs and LAs shall be included in the regulatory mechanisms for each source, and ambient monitoring to assess watershed-wide waterbody conditions shall be conducted either individually or cooperatively among all dischargers.
Cal. Code Regs. Tit. 23, § 3939.45