Water quality: permits.

Assembly Member Papan's water quality legislation directs the State Water Resources Control Board to establish a unified statewide permit system regulating stormwater discharges from large commercial, industrial, and institutional properties. The proposed National Pollutant Discharge Elimination System (NPDES) order would apply to facilities of five acres or more with impervious surfaces that contribute pollutants to federally protected surface waters.

The State Board must publish a draft order by December 31, 2028, or within 18 months after reissuing the current statewide industrial stormwater permit, whichever occurs later. Alongside this draft, the Board must develop a model agreement outlining how permitted facilities can partner with local municipalities on offsite stormwater capture and reuse projects. The order will present multiple compliance pathways for meeting water quality standards, including options for both onsite and offsite stormwater management.

To streamline oversight, facilities would operate under a single NPDES permit incorporating all applicable effluent limitations for industrial stormwater discharges. This consolidation excludes construction-related stormwater permits, which remain separate. The measure builds upon existing federal Clean Water Act requirements while centralizing permit administration at the state level rather than through regional water boards.