Sanitary Sewer Systems Waste Discharge Requirements Order

A sanitary sewer overflow (SSO) is any overflow, spill, release, discharge, or diversion of untreated or partially treated wastewater from a sanitary sewer system. SSOs are a potential hazard that may reach surface and ground waters, potentially impacting public health and aquatic life. Due to these spills, the State Water Board has created a regulatory reporting system for these spills, and have reissued the general order which, among other things, expanded the requirements for the Sewer System Management Plan (SSMP). The order takes a proactive approach to ensure public entities that own or operate sanitary sewer systems of a certain size that collect and convey wastewater to a publicly owned treatment facility in the State have a system-wide operation, maintenance, and management plan in place to reduce the number and frequency of SSOs. CASA, alongside with other associations, has been very involved in the stakeholder workshops to ensure that the reissued general order follows the best science and does not create a system that does not work in the wastewater sector. After the adoption of the reissued general order in December of 2022, CASA has continued to engage with stakeholders and State Water Board staff to ensure compliance and understanding of the reissued order.

Comment Letters



Wednesday, November 1, 2023


Wednesday, May 3, 2023


Wednesday, March 22, 2023


Wednesday, January 11, 2023