Construction at the Southeast Treatment Plant
Overview
Built in 1952, the Southeast Treatment Plant is the City’s largest wastewater treatment facility, handling nearly 80% of San Francisco's combined stormwater and wastewater every year. However, many of its facilities are past their useful life and generate odors that impact the neighborhood.
The SFPUC is currently investing over $3 billion in critical upgrades to transform this facility into a modern resource recovery center. By doing so, we will continue to protect our communities and environment while creating an attractive workplace and neighborhood asset that serves the entire City for decades to come.
As we continue to make progress with our infrastructure investments, we are proud to be providing jobs and contracting opportunities to local residents and businesses. When complete, the plant will work better, look better, and smell better for the neighborhood, our staff, and the entire City!
CONSTRUCTION UPDATES (Late Fall 2025)
Demolition of Old Headworks Building Nears Completion
The final scope of the New Headworks Facility Project is nearing its completion. Earlier this year, crews began demolition of last portion of the old headworks on the northwest side of the Southeast Treatment Plant. This 150-million-gallons per day (MGD) wastewater facility was deemed redundant with the successful completion and activation of the new 250 MGD headworks that began operations in Summer 2024 and has already processed billions of gallons of combined wastewater since opening. Demolition of this decommissioned facility has been ongoing this summer and is still expected to be completed by late Fall 2025.
Learn more about the New Headworks Project, including impacts expected during demolition at sfpuc.gov/headworks.
New Digester Painting Continues
Part of the aesthetic upgrades to five new digesters at the Southeast Treatment Plant is now visible as crews on the Biosolids Digester Facilities Project continue painting the exterior of each digester in a colorful new pattern! The color scheme - a selection of muted blues and greens - is meant to evoke the wastewater cleaning process. Crews have already started to prime the 60-feet digesters and work to paint each one began in late July and will continue through late Fall 2025. The newly painted digesters will be particularly visible to commuters passing the west side of the treatment plant on Caltrain and drivers on the I-280 overpass.
Learn more about the Biosolids Digesters Facilities Project online at sfpuc.gov/digesters.
Construction to Begin in Late Fall 2025 on New Operations, Engineering, and Maintenance Buildings at the Corner of Phelps Street and Jerrold Avenue
In late Fall 2025, construction will start on two new buildings that will provide much-needed shop space for maintenance and trade crews as well as workspaces and facilities for operation, engineering, and maintenance staff. The buildings will also be the SFPUC and City of San Francisco's first Mass Timber buildings. Construction is expected to last roughly two years. These critical upgrades are part of where your ratepayer dollars go to ensure our system continues to protect public health and the environment.
While the contractor is required to abide by the City's noise and vibration ordinances, neighbors should expect some noise and limited dust during this work. The project team will work to minimize disruption to normal neighborhood activity.
Learn more about the New Operations, Engineering, and Maintenance Buildings Project online at sfpuc.gov/sepbuildings.
Biosolids' Biogas Utilization Project
The Biogas Utilization Project is a key component of the Biosolids Digester Facilities Project, designed to transform how biogas—a byproduct of wastewater treatment—is managed and reused. Instead of using biogas for on-site energy generation as originally planned, the SFPUC will upgrade it to pipeline quality renewable natural gas for injection into PG&E’s natural gas pipeline.
Duration: construction on this project will begin in January 2026 with an anticipated completion date of early 2027.
Questions? Contact our team by calling our hotline at (415) 551-4SEP (4737) or email ssip@sfwater.org.
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Project Background
The Southeast Treatment Plant (SEP) operates 24/7 to protect public health and the environment. For more than 70 years, San Francisco has relied on SEP to treat the majority of its wastewater. We are making generational investments so this vital facility can continue to work around the clock.
Two of the largest projects are the Biosolids Digester Facilities Project (BDFP) and New Headworks Facility Project.
Future work at the Southeast Treatment Plant will include new operations, engineering, and maintenance buildings to replace and consolidate aging SFPUC facilities to a central location at the Southeast Treatment Plant.
Construction is progressing on the Biosolids Digester Facilities Project. Projects at the SEP will:
- Continue to protect public health and the environment
- Minimize odors using advanced odor control
- Increase operational reliability and efficiency of the treatment processes
- Improve the ability to withstand a 7.8 earthquake on the San Andreas Fault
- Provide a more attractive look to the facilities to better fit in with the neighborhood
- Fund public art by local artists in support of the Bayview Arts Master Plan
- Provide opportunities for local workers and businesses
The New Headworks Facility under construction in 2024 Funding for this project has been provided in full or in part through an agreement with the State Water Resources Control Board. California’s Clean Water State Revolving Fund is capitalized through a variety of funding sources, including grants from the United States Environmental Protection Agency and state bond proceeds. The contents of this document do not necessarily reflect the views and policies of the foregoing, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
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Construction Progress
New Headworks Facility: Work continued on the New Headworks Project in 2024 and the facility was placed in-service on August 5, 2024. As of January 7, 2025, New Headworks has processed approximately 9 billion gallons of combined stormwater and sewer water flows.
2024 also saw the completion of the new public art wall titled Whorl Whirl: Our Circular Nature by the noted artist Norie Sato. The 335-feet long and 35-feet high artwork installation - which draws inspiration from resource recovery processes and infrastructure at the Southeast Treatment Plant - runs along the north perimeter of the New Headworks facility on Evans Avenue between Rankin and Quint streets.
Work continues in 2025 on distributed control system testing, Evans streetscape restoration, Southeast Influent Pumping, fire alarm testing, and completing work on elevators inside the facility.
The New Headworks Project is anticipated to reach final completion in June 2025.
Biosolids Digester Facilities (BDFP): 2024 saw the majority of the concrete and steel work on the Solids Pretreatment and Biosolids Dewatering Buildings completed. In addition, the roughly 60,000-pound domed steel covers were installed on all five digesters and testing is well underway in the Digester Building.
The focus for 2025 will be construction of the remaining facility for the Thermal Hydrolysis Process, Odor Control, Steam Generation and ancillary facilities, as well as mechanical, electrical and controls work in all facilities.
Testing on the new facilities will begin in 2026, with the introduction of process fluids to the new digesters in the Fall of that year. Substantial completion is anticipated in 2027, with an anticipated final completion in 2028.
Award Winning: In February 2025, the Biosolids Project earned the Occupational Excellence Achievement Award from the National Safety Council for a second consecutive year. The criteria are high to earn the annual award and includes having a 'lost workday' case incident rate better than or equal to 50% of the Bureau of Labor's statistics rating for North American Industry Classification System code, and zero fatalities during the calendar year.
In addition, in 2023, the project achieved the Envision Platinum award for sustainable infrastructure from the Institute for Sustainable Infrastructure (ISI). This is ISI’s highest certification level! The Envision award is comparable to the Leadership in Energy and Environmental Design (LEED) building certification but for public and private industrial infrastructure.
New Biogas Utilization Project: As part of the Biosolids Digester Facilities Program, the Biogas Utilization Project will provide 100% beneficial use of the biogas generated by the digesters during the solids-digestion treatment process. The Project will convert the biogas into renewable natural gas to enhance sustainability, reliability, and affordability. Producing RNG is in line with City and State renewable energy and sustainability policies and practices as it displaces the use of fossil fuels. This represents the best beneficial use of this valuable resource and exemplifies SFPUC’s role as environmental stewards.
Jobs and Contracts:
We are proud of the success our Local Hire and Local Contracting efforts are having in meeting or exceeding the City’s aggressive goals. Check out the most recent SSIP Jobs & Contracts report. You can also keep up to date with our Project Labor Agreement.
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Project Materials
