Stormwater Discharge Permit
The Federal Clean Water Act regulates how municipalities release stormwater into local waterways, including the requirement to obtain Stormwater Discharge Permits.
In the San Francisco Bay Area, the Regional Water Quality Control Board issues these five-year permits to cities, counties and flood control districts. The most recent Stormwater Discharge Permit was issued in May 2022 to municipalities in five Bay Area counties (Alameda, Contra Costa, San Mateo, Santa Clara and Solano Counties).
Each permit specifies best management practices (BMPs) to reduce or eliminate stormwater pollution. The current Stormwater Discharge Permit imposes the following pollution reduction requirements:
- Litter: Reduce trash discharge from storm drains by 90% by 2023 and 100% by June 2025.
- PCBs and Mercury: Reduce mercury by 50% by 2028 and PCBs in stormwater by 90% by 2030.
- Construction Sites: Reduce erosion and control sediment at construction sites.
- New Developments: Divert stormwater water through a bio-filtration system prior to discharge to the storm drain.