Cal. Code Regs. tit. 23 § 3929.14
The Central Coast Regional Water Quality Control Board (Central Coast Water Board) periodically revises and amends the Water Quality Control Plan for the Central Coastal Basin (Basin Plan). The Central Coast Water Board has determined the Basin Plan requires amendment to incorporate total maximum daily loads (TMDLs) and an implementation strategy for nitrogen compounds and orthophosphate in streams of the Pajaro River basin. TMDLs are a requirement of the federal Clean Water Act. Waterbodies assigned TMDLs by this action include the Pajaro River, Watsonville Slough, Llagas, San Juan, and Furlong creeks, and other tributary surface waterbodies as identified in the Basin Plan amendment.
The Central Coast Water Board adopted this Basin Plan amendment by Resolution No. R3-2015-0004 at the July 30, 2015 board meeting. Further, this action by the Central Coast Water Board was subsequently approved by the State Water Resources Control Board by Resolution No. 2016-0018 on April 5, 2016.
The Central Coast Water Board's goal for establishing these TMDLs in the Pajaro River basin is to rectify water quality impairments related to nitrate, un-ionized ammonia, and orthophosphate, thereby providing support for the designated beneficial uses of municipal and domestic water supply, cold and warm fresh water habitat, groundwater recharge, agricultural water supply, and to support water quality standards attainment with regard to the Basin Plan's general toxicity water quality objective for un-ionized ammonia, and the Basin Plan's water quality objective for biostimulatory substances.
Responsibility for achieving pollutant load reductions falls upon several entities as described in Attachment A to Resolution No. R3-2015-0004 (Basin Plan amendment). The Central Coast Water Board is relying on existing regulatory measures in the river basin to ensure TMDL implementation is carried out by implementing parties. These regulatory measures include NPDES stormwater permits, NPDES wastewater permits, and the Conditional Waiver of Waste Discharge Requirements for Discharges from Irrigated Lands (Order No. R3-2012-0011, as modified by Order WQ-2013-0101). Further, this Basin Plan amendment utilizes an implicit margin of safety to account for uncertainties.
Interim and final implementation milestones of 10, 15, and 25 years are established for showing progress towards, and attainment of relevant water quality standards. The Central Coast Water Board will track progress towards achieving the TMDLs through review of implementation actions and monitoring conducted by the implementing parties.
Cal. Code Regs. Tit. 23, § 3929.14