Sewer System Management Plan

To provide a consistent, statewide regulatory approach to address the issue of sanitary sewer overflow (SSO), the State Water Resources Control Board (State Water Board) adopted Statewide General Waste Discharge Requirements (WDRs) for Sanitary Sewer Systems, Water Quality Order Number 2006-0003 (Sanitary Sewer Systems WDR) on May 2, 2006. The Sanitary Sewer Systems WDR requires public agencies that own or operate sanitary sewer systems to develop and implement sewer system management plans and report all SSOs to the State Water Board’s online SSO database.

On August 6, 2019, the City Council approved an updated Diamond Bar Sewer System Management Plan that confirms the City's commitment to controlling and responding to overflows. State law requires that the Plan be reviewed, updated and recertified every five years.