State law requires that construction projects that impact more than 10,000 square feet of impervious area or auto service facilities, gas stations, restaurants, and uncovered parking lots that impact more than 5,000 square feet, treat their stormwater onsite. In addition, construction projects that impact more than 2,500 square feet must install one or more site design measures to treat some of the stormwater onsite. For projects that create and replace one acre or more of impervious area, stormwater will need to be treated and runoff flow controls will also be needed. The City of San Pablo is a member of the Contra Costa Clean Water Program which consists of all the jurisdictions in the County. The Program has developed guidance for developers in meeting these requirements. Please visit the Contra Costa Clean Water Program or call the City at (510) 215-3064 for more information.