The amendments for the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (SIP) consist of:
The language of the SIP has been amended to allow Regional Water Quality Control Boards (Regional Water Boards) to use discharger-specific WERs in the National Pollutant Discharge Elimination System (NPDES) permitting process. The development of WERs would still have to use U.S. Environmental Protection Agency (USEPA) guidance or other scientifically defensible protocols, but the approvals of WERs by the State Water Resources Control Board (State Water Board) and USEPA through the adoption of a Regional Water Quality Control Plan provision would not be required. The State Water Board and USEPA would still be involved in the development of the WER through the public review process of the NPDES permit containing the proposed Site-Specific Objective and associated effluent limit.
The language of the SIP has been amended to allow the reasonable potential Step 6 trigger to apply only to situations where ambient background concentrations are greater than the water quality criterion or objective, and the pollutant is detected in the effluent. Language would also be added to require monitoring in situations where ambient background concentrations are greater than the water quality criterion or objective, and the pollutant is not detected in the effluent.
The SIP has been amended to incorporate changes that improves clarity and provides a better understanding of how SIP provisions are to be applied in permits. The changes also reduce inconsistencies in permits written by different Regional Water Boards.
Cal. Code Regs. Tit. 23, § 2914.5
Note: Authority cited: Section 13140, Water Code. Reference: Sections 13142 and 13143, Water Code.