Cal. Code Regs. tit. 23 § 3979.4
On October 29, 2010, the Santa Ana Regional Water Quality Control Board (Santa Ana Water Board) adopted Resolution No. R8-2010-0039, amending the Water Quality Control Plan for the Santa Ana Region. The State Water Resources Control Board (State Water Board) approved the amendment under Resolution No. 2012-0006 on February 7, 2012.
Resolution No. R8-2010-0039 establishes a second set of TDS and nitrate-nitrogen objectives for the San Jacinto Upper Pressure Management Zone. This second, less stringent set of objectives is based on the finding that water quality consistent with "maximum benefit to the people of the State" will be maintained (the "maximum benefit" objectives), provided that specific water and wastewater projects and programs are implemented by the principal agency that oversees water supply and wastewater collection and treatment -- Eastern Municipal Water District. These project and program commitments, and compliance dates, are delineated in the Implementation Plan and include requirements for implementing salt reduction programs when management zone TDS and/or nitrate-nitrogen reach specified concentration trigger points. Finally, with regard to the implementation of the "maximum benefit" objectives, if the Regional Board determines that Eastern Municipal Water District has not complied with the specified requirements for implementation of projects/programs, the Regional Board, at a duly noticed public meeting, would make the determination that the lowering of water quality is not of "maximum benefit" to the people of the state and by default, the established TDS and nitrate-nitrogen historical "antidegradation" Basin Plan objectives, which are based on historical quality conditions, would apply. In this situation, the Regional Board will require mitigation for TDS and nitrate-nitrogen discharges in excess of waste discharge limitations based on the antidegradation objectives.
Cal. Code Regs. Tit. 23, § 3979.4