Every time you flush the toilet, take a shower, brush your teeth, do your laundry, or wash the dishes, the resulting wastewater is collected and treated by the City's sewer system. Learn how San Francisco collects and treats sewage from homes and businesses, stormwater (rainwater), and street runoff into the drains.
San Francisco is the only coastal city in California with a combined sewer system that collects and treats both wastewater and stormwater in the same network of pipes. Learn more about our combined sewer system.
San Francisco's combined sewer system includes a network of pipes, treatment plants, catch basins, storm drains, and storage/transport boxes. Learn how all these parts work together in our combined sewer system.
We separate liquids from solids in several phases during our processing, and we treat each separately. Learn more about the different wastewater treatment processes for liquids.
We separate liquids from solids in several phases during our processing, and we treat each separately. Learn more about our different wastewater treatment processes for solids--from sludge into biosolids, a recycled product that can be used as a fertilizer replacement.