In response to the federal Clean Water Act, all municipalities are regulated waste dischargers under a National Pollutant Discharge Elimination System (NPDES) Permit administered by the appropriate Regional Water Quality Control Board.
Accordingly, the municipalities are regulated with regard to their jurisdiction over and/or maintenance responsibility for municipal storm drain systems and watercourses that they own or operate. The NPDES Permit is concerned primarily with regulating trash, pollutants of concern and excessive hydrologic runoff which can carry sediment and cause flooding.
Bay Area Stormwater Programs worked with The San Francisco Bay Regional Water Quality Control Board to draft a ground-breaking Bay Area wide Municipal Regional Permit (MRP) that encompasses the permittees of Alameda, Contra Costa, Santa Clara, San Mateo counties, and permittees of the cities of Fairfield - Suisun, and Vallejo. The MRP "levels the playing field" and subjects all permittees to virtually the same requirements, allowing some room for flexibility.
Municipal Regional Stormwater NPDES Permit (MRP)
Provision C.3 in the MRP requires site designs for new developments and redevelopments to minimize the area of new roofs and paving. Where feasible, pervious surfaces should be used instead of paving so that runoff can infiltrate to the underlying soil. Remaining runoff from impervious areas must be captured and used or treated using bio-retention. In some developments, the rates and durations of site runoff must also be controlled.
In addition, project applicants must execute agreements to allow municipalities to verify that stormwater treatment and flow-control facilities are maintained in perpetuity.
The California Regional Water Quality Control Board for the San Francisco Bay Region adopted the MRP in October 2009. The MRP governs discharges from municipal storm drains operated by 76 local government entities, including those in Vallejo.
The C.3 requirements are separate from, and in addition to, requirements for erosion and sediment control and for pollution prevention measures during construction.
Effective December 1, 2012, projects that create or replace 2,500 square feet or more, but less than 10,000 square feet, of impervious surface must implement site design measures to reduce stormwater runoff.