Our Wastewater Service Charges cover the cost of collecting, transporting, treating and disposing of each unit of wastewater discharged into the sewer system. Wastewater service charges are calculated by multiplying water consumption by an assigned flow factor.
What is flow factor?
The flow factor is the percentage of metered water use returned to the sewer system as wastewater. For purposes of determining applicable charges, the percentage of water use returned to the sewers (flow factor) is assumed to be 90% for single-family residential users and non-residential users and 95% for multifamily residential users.
Residential users may be eligible for a reduced flow factor if they are using large amounts of water to irrigate a lawn or garden and believe their annualized irrigation consumption is greater than 10%. Customers may request that their flow factor be reviewed by filing an appeal for a reduction of their sewer service charge.
Appeals should be submitted to:
San Francisco Water, Power and Sewer
Customer Services, High Consumption Unit
525 Golden Gate Avenue, 2nd Floor
San Francisco, CA 94102
Each appeal form must contain the name and address of the residential user and a statement that substantiates the percentage of incoming water discharged to the sewer. All customers will be notified in writing of the department’s decision. For questions regarding residential appeals, please contact the High Consumption Unit at (415) 551-4780.
Non-residential customers who want to appeal their sewer service charge should contact the Bureau of Environmental Regulation Management at (415) 695-7310.