Nearly one million residents, businesses and visitors rely on the City’s sewer system to remove our wastewater and storm water and protect public health and the surrounding marine environments. Every time you flush your toilet, wash your dishes and clothes, or take a shower, your wastewater empties through pipes in your home into San Francisco’s combined sewer system. Each day more than 80 million gallons of wastewater is collected and transported to treatment plants, where pollutants like human wastes, oil and pesticides are removed before reaching the San Francisco Bay and Pacific Ocean. In fact, every six days, San Francisco generates enough wastewater to fill a football stadium from top to bottom!
Currently, all wastewater and storm water is transported through over 1,000 miles of pipelines and tunnels under the City, to 20 pump stations, several force mains, and ultimately to three wastewater treatment plants. Wastewater is treated at these plants to remove harmful pollutants, and the treated and cleaned wastewater is then transported through large pipes – or “outfalls” into the bay or ocean.
San Francisco’s hilly terrain reduces the need to use electrical and mechanical pumps to move wastewater, providing cost savings. It also creates an eastern or “bayside” and western or “westside” division in the wastewater system.
