Amending the Water Quality Control Plan for the Central Coastal Basin to Adopt Total Maximum Daily Loads for Nitrogen Compounds and Orthophosphate in Streams of

Amending the Water Quality Control Plan for the Central Coastal Basin to Adopt Total Maximum Daily Loads for Nitrogen Compounds and Orthophosphate in Streams of

The Central Coast Regional Water Quality Control 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 SWRCB by Resolution No. 2016-0018 on April 5, 2016. The Central Coast Water Board's goal for establishing this Basin Plan amendment is to rectify water quality impairments related to nitrate, un-ionized ammonia, and orthophosphate, thereby providing support for the designated beneficial uses of surface waters in the river basin. Responsibility for achieving pollutant load reduction falls upon several entities as described in Resolution No. R3-2015-0004. The Central Coast Water Board is relying on existing regulatory measures int he 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 TMDL through review of implementation actions and monitoring conducted by the implementing parties. If existing efforts are not expected to achieve the TMDLs, the Executive Officer or the Central Coast Water Board may require changes to existing monitoring, reporting, or implementation efforts pursuant to CA Water Code Sections 13263, 13267, or 13383.

San Luis Obispo