Municipal Stormwater Program

Phase I

The federal Clean Water Act (CWA) was amended in 1987 to address urban stormwater runoff pollution of the nation’s waters. In 1990, US EPA promulgated rules establishing Phase 1 of the National Pollutant Discharge Elimination System (NPDES) stormwater program. The Phase 1 program for Municipal Separate Storm Sewer System (MS4s) requires operators that serve populations of 100,000 or greater to implement a stormwater management program as a means to control polluted discharges from these MS4s.

The Water Board issued county-wide municipal stormwater permits in the early 1990s to operators of MS4s serving populations over 100,000 (Phase 1). On October 14, 2009, the Water Board re-issued these county-wide municipal stormwater permits as one Municipal Regional Stormwater NPDES Permit to regulate stormwater discharges from municipalities and local agencies in Alameda, Contra Costa, San Mateo, and Santa Clara counties, and the cities of Fairfield, Suisun City, and Vallejo.



Phase II

In 1999, the Phase II Rule automatically covered all small MS4s (not covered by the Phase I program) located in urbanized areas as defined by the Bureau of the Census. The State Water Resources Control Board issued a General Permit for Discharge of Storm Water from Small MS4s. The following municipalities are covered under this General Permit:
  • Marin County and its Cities
  • Napa County and its Cities
  • City and County of San Francisco
  • Solano County and the City of Benicia
  • Sonoma County and the Cities of Petaluma and Sonoma


Staff Contacts:


Selina Louie 510-622-2383
(Alameda County, Contra Costa County)

Sue Ma 510-622-2386
(San Mateo County, Santa Clara County)

Jolanta Uchman 510-622-2432
(City of Fairfield, City of Suisun City, City of Vallejo, Vallejo Sanitation and Flood Control District, Solano County)

Marla Lafer 510-622-2348
(Marin County)

Fred Hetzel 510-622-2357
(Napa County, San Francisco City and County)

Abigail Smith 510-622-2413
(Sonoma County)