San Diego Region - Sanitary Sewer Overflows

Sanitary sewer systems convey wastewater from homes, businesses, and industries to municipal wastewater treatment plants. Sanitary sewer overflows (SSOs) are spills of untreated or partially treated wastewater from sanitary sewer systems. SSOs typically contain high levels of pathogens, toxicants, nutrients, and other pollutants that threaten public and environmental health, and impair the recreational uses and aesthetic enjoyment of our waters.

The State Water Resource Control Board (State Board) adopted Order No. 2022-0103-DWQ, Statewide Waste Discharge Requirements General Order for Sanitary Sewer Systems (Statewide WDRs) on December 6, 2022. The Statewide WDRs became effective on June 5, 2023. The Statewide WDRs establishes minimum requirements to prevent SSOs. The Statewide WDRs regulates public agencies that own/operate sanitary sewer systems greater than one mile in length, and gives the Regional Water Boards discretion to regulate sanitary sewer systems of any size that are owned/operated by public agencies, federal agencies, or private entities.  Agencies enrolled in the Statewide WDRs are required to develop and implement sewer system management plans and report all sanitary sewer spills to the State Water Board’s online California Integrated Water Quality System (CIWQS) Sanitary Sewer System Database.

The San Diego Water Board adopted Order No. R9-2007-0005, Waste Discharge Requirements for Sewage Collection Agencies in the San Diego Region (San Diego Region WDRs) on February 14, 2007. The San Diego Region WDRs strictly prohibit SSOs from sanitary sewer systems. The San Diego Region WDRs supplement the Statewide WDRs and apply to all sewage collection agencies in the San Diego Region enrolled under the Statewide WDRs.

Online SSO Database

SSOs are reported by sewage collection agencies to the San Diego Water Board using the California Integrated Water Quality System (CIWQS), the State Water Board's regulatory and water quality information management system. The State Water Board website also includes an interactive geographic interactive system (GIS) mapping tool which can be used to spatially display SSOs reported to the CIWQS SSO database. Below are links related to the CIWQS SSO database and State Board GIS mapping tool:

Permits and Related Documents

Additional Resources


To Report a Spill in the San Diego Region call:

The San Diego Water Board Front Desk at 619-516-1990.

For questions about WDRs and SSO Reporting, contact .

James Chhor
(619) 521-5899