Skip to page body Home Customer Service How To Environment Projects & Programs About Us

Southeast Treatment Plant

constructing a legacy thumb

SSIP: Constructing a Legacy

As we make critical investments in our infrastructure, our community benefits program is also investing in a sustainable future for the people and places that make our region so special. Check out this video on our Southeast Treatment Plant upgrades.

Aerial Photo of SEP

Snapshot of SEP

Built in 1952, serves bayside.

Largest dry weather facility in San Francisco, treating 80% of the City’s flows.

Treats 57 million gallons per day (MGD) of wastewater and up to 250 MGD during rain storms.

Located on Phelps Street near Third and Evans streets in the Bayview District.


 SEP Fact Sheet July 2019

Treatment Plant Factsheet

Located in Bayview Hunters Point, the Southeast Treatment Plant (SEP) is nestled in the midst of a mixed industrial, commercial and residential area; with some neighbors only a street’s width away from the treatment plant.


The SEP is San Francisco’s largest and oldest wastewater facility, responsible for treating nearly 80% of the City's flow. Wastewater is transported to the SEP through a grid of transport/storage facilities, sewers, and five major pump stations. The SEP treats 57 million gallons per day (MGD) of wastewater and handles 160 wet tons of biosolids each day. During a rainstorm, it has the capacity to treat up to 250MGD of wastewater.

The Need for Improvement

Built in 1952, many parts of the SEP facilities represent 1940’s technology and are operating well beyond their useful lives. Through the Sewer System Improvement Program (SSIP), the SEP will undergo operational improvements and seismic upgrades in order to ensure the reliability of the sewer system and to protect the health of our community and environment.


These proposed SSIP improvements incorporated public input from the Southeast Digesters Task Force, an advisory group of neighborhood and business interests who provided recommendations on reducing community impacts. Check out our page dedicated to the upgrades going on at the Biosolids Digester Facilities.

Planned Improvements

  • New Biosolids Digester Facilities
  • New Headworks Facility
  • Structural and seismic retrofits
  • Upgrades to oxygen and influent pumps
  • Odor control improvements
  • Architectural and landscape improvements to the perimeter

Project Benefits

  • Improved process performance
  • Odor control
  • Seismic improvements
  • Improved operating reliability and efficiency
  • Minimized neighborhood impacts
  • Improved visual aspects of the plant
  • Upgrades to the existing digesters and new digesters facilities


    Last updated: 7/26/2019 9:49:08 AM