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. 2006-0003-DWQ, Statewide General Waste Discharge Requirements for Sanitary Sewer Systems (Statewide WDRs) on May 2, 2006. The Statewide WDRs establishes minimum requirements to prevent SSOs. All federal and state agencies, municipalities, counties, districts, and other public entities that own, operate, acquire, or assume responsibility for sanitary sewer systems greater than one mile in length and that collect and/or convey untreated or partially treated wastewater to a publicly owned treatment facility in the State of California are required to apply for coverage under the Statewide WDRs.

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:

Executive Officer Reports

Reports summarizing SSOs in the San Diego Region are available in the Executive Officer's Reports for the following months:

Permits and Related Documents

Additional Resources


To Report a Spill in the San Diego Region call 619-516-1990.

For questions about WDR's and SSO Reporting, see contact info.

WDRs Contact:

SSO Reporting Contact: