Unclogging Our Sewers
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In San Francisco, both wastewater and storm water flows are combined into one sewer system. Fats, oils, and grease (FOG) down kitchen drains dramatically impact the flow and performance of our combined sewer system. When disposed down the drain, FOG forms thick layers inside sewer lines causing clogged pipes. Clogged sewers result in unsanitary back-ups, overflows onto streets, foul-smelling odors, and costly damage to sewer infrastructure. In 2006, 2600 sewer service calls were due to grease-related blockages. That’s about seven sewer calls per day around the City, every day.
For these reasons, the SFPUC Water Pollution Prevention Program targets FOG as a “pollutant of concern.” This agency is responsible for water pollution programs that improve water quality through pollution prevention strategies.
Click here to view a pdf of FOG Map and see where in the City has the most clogged sewer problems.
Solving our $3.5 Million Problem
Residential kitchens and commercial restaurants are the largest controllable sources of FOG in the City’s sewer system. The City spends approximately $3.5million each year clearing FOG out of the pipes.
The SFPUC is helping restaurants and residents keep their FOG out of the drain by:
- Teaching restaurant owners and managers about best management practices and grease trap installation to keep FOG from entering drains from the start.
- Providing information and resources to handle grease responsibly, including a list of local grease trap service providers
- Launching SFGreasecycle, the SF PUC Biofuel Program offering restaurants free waste vegetable oil collection to be rendered into biodiesel to fuel City fleet.




