About the Clean Water Program

The Clean Water Program is a comprehensive plan to upgrade the aging wastewater collection and treatment system with advanced infrastructure that will provide reliable services for years to come. The Wastewater Treatment Plant components of the Clean Water Program are a joint effort between the City of San Mateo and City of Foster City/Estero Municipal Improvement District (EMID). The City of Foster City is a partial owner of the Wastewater Treatment Plant.

The Goals of the Clean Water Program are to:

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Replace aging infrastructure and facilities

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Build wet weather sewer system capacity assurance to prevent overflows

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Meet current and future regulatory requirements

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Align with the City of San Mateo and Foster City’s sustainability goals

Why Do We Need Improvements?

The City’s infrastructure is aging and will continue to deteriorate and to have failures over time. During heavy rains, the wastewater collection system is overwhelmed which leads to the occurrence of sanitary sewer overflows that leak diluted raw sewage and pollutants onto our communities’ streets and into our creeks, beaches, lagoon, and the San Francisco Bay. During these heavy rain events, excess flows to the wastewater treatment plant can only be partially treated, which does not meet current and future regulatory discharge permit requirements. Sanitary sewer overflows and the partial treatment of wastewater at the treatment plant are significant health concerns that negatively impact the community and the environment.

The regulatory environment that protects our communities also continues to change.  Not completing these wastewater collection and treatment improvements will lead to the City of San Mateo, and its regional partner agencies, failing to comply with the Regional Water Quality Control Board’s Cease and Desist Order and the National Pollutant Discharge Elimination System permit requirements. Failure to comply with these requirements could result in large fines that would be passed on to ratepayers and continued public health and environmental concerns.

How Does the Wastewater System Work?

Have you ever wondered where used water (“wastewater”) goes after it leaves your home or business? Did you know that it eventually reaches the San Francisco Bay? When wastewater leaves your property, it first travels through a series of sewer pipes and pumps called a sewer collection system before reaching the Wastewater Treatment Plant. At the Wastewater Treatment Plant, the wastewater is treated to meet water quality standards set by the State of California before it can flow into the Bay.

Read Wastewater: The Basics to learn all about San Mateo’s sewer collection system and Wastewater Treatment Plant!