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Mariposa Pump Station Improvements Project

Essential Construction and Field Work Continues 
We hope you and your loved ones are safe and staying connected during these challenging times. The SFPUC is focused on the health of our teams and continued delivery of our critical water, power and sewer services. You may see our field or construction crews at work maintaining, repairing and upgrading our essential infrastructure. We are making sure they do so as safely as possible. We ask the public to please maintain proper social distance from our crews as they work.

Here are key resources on what you can do to protect yourself and others. New information is posted as it becomes available: 
  • San Francisco’s Resource Page:
  • includes Covid-19 updates and resources for your water, power and sewer services. 

  Project Materials 
Fact Sheet

   Contact Us!

Project Purpose and Need

The San Francisco Public Utilities Commission (SFPUC) operates a combined sewer system that collects and treats wastewater (sewage and stormwater). Originally built in 1954, the Mariposa Pump Station (MPS) is a dry-weather pump station that pumps wastewater from the surrounding area to the Southeast Treatment Plant for treatment. 

The Mariposa Pump Station Improvements Project will demolish the existing pump station and construct a new pump station at the same location to accommodate full buildout of the Mission Bay community, the new Warriors Arena and planned population growth in the Potrero Hill neighborhood. These facilities are a critical component of San Francisco’s wastewater operations and planned upgrades will allow us to meet the seismic standards and sea level rise requirements in San Francisco, as well as continue offering reliable, high-quality service to all who live, work and play in San Francisco.

Project Benefits
  • Maintain critical sewer system services by increasing the existing dry weather capacity of the MPS.
  • Meet seismic standards and sea level rise requirements.
  • Increase sewer system reliability.
  • Protect water quality and aquatic life in the Bay.
  MPS Aerial Render
Render of proposed pump station design.

Project Schedule 
Winter 2019 - Summer 2021

MPS Map August 2019

Click the image above to see a larger version of the map.

What to Expect During Construction

Crews will work to reduce traffic disruption in the surrounding area.

  • SCHEDULE: To minimize construction duration and impacts to community, construction crews will be working Monday through Friday between 7:00 am and 5:00 pm. Some weekend work may be required, at which time advance notice will be provided.
  • NOISE: Noise level of work will be conducted in compliance with the San Francisco Noise Ordinance.
  • SEWER SERVICE: Service in the area will NOT be interrupted during construction.
  • ACCESS: Businesses and residents in the work zone will maintain access to their driveways and entrances.
  • TRAFFIC: During construction, vehicular, bicycle, and pedestrian traffic may be impacted. If necessary, through traffic may be temporarily detoured around the construction site.
  • PARKING: Street parking will not be allowed near construction zones. “No-parking” signs will be posted 72 hours in advance.
  • ODORS: If necessary, odor control measures will be in place during construction.
  • MUNI: No bus impacts are expected at this time.
  • NOTICE: A 30-day and 10-day notice will be distributed prior to construction to residents and businesses within the project area detailing traffic impacts and project details.

About the SSIP

The San Francisco Public Utilities Commission (SFPUC) recently launched the Sewer System Improvement Program (SSIP), a 20-year citywide investment to upgrade our aging sewer system and provide a more reliable, sustainable, and seismically safe system now and for future generations. The SSIP includes a series of facility upgrades at the Southeast Treatment Plant (SEP) located in the Bayview neighborhood of San Francisco. Click here to learn more about the SSIP.


Last updated: 3/20/2020 11:18:33 AM