About Us


Central San is a special district responsible for the collection and treatment of wastewater in a 146 square mile area of central Contra Costa County. Our mission is to protect public health and the environment.

What is a Special District?

Central San is one of 49 special districts in Contra Costa County, and one of 3,400 special districts in California.

Special districts are local public/government agencies established by residents of a community to provide a service not provided by the county or city.

Special districts are either enterprise districts that bill customers directly or through property taxes (such as Central San) or non-enterprise districts that are funded by voter-approved taxes or assessments (e.g., recreation or fire districts).

Special districts hold regularly scheduled public meetings where citizens are invited to ask questions, voice their concerns, and provide feedback. At Central San these meetings, and the District, are governed by a five-member Board of Directors.

For further information on special districts, visit the California Special Districts Association website.