Protecting the Bay for a Sustainable Future


Have you ever wondered where used water (“wastewater”) goes after it leaves your home? Did you know that it eventually reaches the San Francisco Bay? It first travels through a series of sewer pipes and pumps called a sewer collection system and then gets treated at the Wastewater Treatment Plant before it is safe to flow into the Bay.

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:


Replace aging infrastructure and facilities

Build wet weather sewer system capacity assurance to prevent overflows

Meet current and future regulatory requirements

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

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

Please visit the Underground Flow Equalization System page for important information on this phase of the Clean Water Program.



Latest Info


Planning Commission Public Meeting – September 24, 2019

On September 24, 2019, the Planning Commission held a public hearing on the Underground Flow Equalization System and the associated Final Environmental Impact Report (FEIR), Site Plan and Architectural Review (SPAR), and Special Use Permit (SUP). At this meeting, staff provided a summary presentation and recommendations to the commission. The Planning Commission voted to recommend the City Council certify the FEIR, adopt the statement of overriding considerations based on the findings for approval, and approve the SPAR and SUP. A public hearing for the recommended certification, adoption, and approvals for the project will be held at the City Council meeting scheduled on October 21 at 7:00 pm at the City Hall Council Chambers.


UPDATE! Additional UFES Final Environmental Impact Report Documents Released

In addition to the Final Environmental Impact Report for the Underground Flow Equalization System Project, two other project documents were released on September 10, 2019: (1) Errata No. 1, which includes 40 additional comments and responses, and (2) the Mitigation Monitoring and Reporting Program, which summarizes the mitigation measures discussed in the EIR and implementation responsibilities. Both can be found on the Final EIR page.


Final UFES Environmental Impact Report Released

The Final Environmental Impact Report for the Underground Flow Equalization System Project is now available. This final version of the document includes responses to written and verbal comments and questions received during the public comment period, which ran from March 6 through May 31, 2019.

The Final EIR is available for download at the Clean Water Program website on our Final Environmental Impact Report page. Hard copies are available at City Hall and the San Mateo Main Library.

The Planning Commission will vote on a recommendation for Final EIR certification, and concurrent Special Use Permit approval, to City Council at its upcoming meeting on September 24, 2019. City Council will vote on certification of the Final EIR, and approval of the concurrent Special Use Permit, at their October 21, 2019 meeting. (Please note – this topic has been moved from the October 7 City Council meeting.)

Planning Commission meetings and City Council meetings are all held at 7:00 pm at City Hall Council Chambers, 330 West 20th Avenue, San Mateo, CA 94403.

Please visit our Underground Flow Equalization System page for additional project details and updates.


San Mateo Breaks Ground on New Wastewater Treatment Plant

On Wednesday, Sept. 4, 2019, the City of San Mateo welcomed Representatives Jackie Speier and Anna Eshoo, along with Foster City Mayor Sam Hindi to celebrate the groundbreaking of our new wastewater treatment plant.

The plant is the largest component of the Clean Water Program, a $1 billion initiative launched in 2015 to modernize the San Mateo sewer system, a response to a Cease and Desist Order from the State of California mandating a sewer system upgrade to eliminate sewer overflows from entering the San Francisco Bay.

“These infrastructure improvements are vital to the sustainability and future of San Mateo,” said Mayor Diane Papan. “We greatly appreciate the advocacy of our council and the support of our Senators Dianne Feinstein and Kamala Harris, as well as congressional representatives Jackie Speier and Anna Eshoo, the encouragement from the EPA and our partners in Foster City, who worked on our behalf to support low-cost funding alternatives for the program.”

The new plant will replace an aging plant that saw its last major upgrade in the 1970s. Construction on Phase I of the new plant begins this month.

“We are five successful years into the largest upgrade to our sewer facilities,” said Public Works Director Brad Underwood. “The Clean Water Program is a necessary and timely endeavor that we must deliver on for the sustainability of our City and the health of the San Francisco Bay.”

The new plant will feature a modernized treatment process meeting the program goals to replace the City’s aging infrastructure and comply with regulatory requirements to prevent sewer overflows and fully treat flows at the plant. The new plant also aligns with the City’s sustainability goals; the administration building will be LEED Silver certified and the plant will produce high-quality effluent that is ready for potential water re-use opportunities. The new plant is set to open in 2024.

Wastewater Treatment Plant Groundbreaking Ceremony

Officials Unite for Sept. 4 San Mateo Groundbreaking – Left to Right, Foster City’s City Manager Jeff Moneda, San Mateo’s Public Works Director Brad Underwood, Hillsborough Vice Mayor Alan Royce, Hillsborough Mayor Shawn Christianson, Foster City Mayor Sam Hindi, San Mateo Mayor Diane Papan, Representatives Anna Eshoo and Jackie Speier, San Mateo Councilmembers Maureen Freschet, Joe Goethals, Eric Rodriguez and Rick Bonilla, and Jim McGrath, Vice Chair, California State Water Resources Control Board.


Underground Flow Equalization System Update to Planning Commission

At the August 27, 2019 Planning Commission meeting, Clean Water Program staff provided an update on the UFES. The UFES project will help to reduce the risk of sewer overflows during heavy storms. The purpose of this UFES Informational Presentation was to familiarize Commission members with important information about the project that has been updated since publication of the Draft Environmental Impact Report in March 2019.   




Upcoming Events


Planning Commission Meeting @ City Hall - City Council Chambers
Sep 24 @ 7:00 pm

At this meeting, information from the Final Environmental Impact Report on the Underground Flow Equalization System will be presented, and the Planning Commission will make a recommendation to City Council for certification of the Final Environmental Impact Report, and concurrent Special Use Permit.

City Council Meeting @ City Hall - City Council Chambers
Oct 21 @ 7:00 pm

At this meeting, the City Council will vote on certification of the Final Environmental Impact Report and approval of the Special Use Permit for the Underground Flow Equalization System.