With 2.6 million customers relying on our water system, we are working to conserve our great Hetch Hetchy drinking water supply and develop alternative water supplies to serve our needs.
What is Recycled Water?
Recycled water is highly-treated wastewater that has been purified through multiple levels of treatment to meet stringent quality and safety standards set by the California Department of Public Health. Treatment typically consists of filtration to remove suspended solids, some bacteria, and other pollutants. Disinfection then destroys any remaining bacteria and viruses, using chemicals (such as chlorine) or non-chemical methods like ultraviolet light.
Recycled water is safe and suitable for a variety of non-drinking uses.
San Francisco’s potential uses of recycled water include: irrigation of parks, medians and other landscaped areas,toilet and urinal flushing, industrial processing and cooling and in decorative fountains.
Historical Use of Recycled Water
San Francisco’s use of recycled water dates back to the early 1900s when the Golden Gate Park area was transformed from “great sand and waste” to a garden spot through the use of partially treated wastewater and groundwater. In the 1930s, the McQueen Treatment Plant was constructed in the Park to provide secondary-treated recycled water to irrigate Golden Gate Park. This practice continued until 1978 when the McQueen plant was shut down because it could not meet the new State standards for irrigation use.
Current Use of Recycled Water
In 2004, we contributed funds to the North San Mateo County Sanitation District (a subsidiary of Daly City) towards the upgrade of their wastewater treatment plant to produce tertiary-level recycled water. This facility currently serves three golf courses (Lake Merced Golf Club, Olympic Club, and the San Francisco Golf Club), two of which are located partially in San Francisco. The use of recycled water at these locations replaces groundwater previously being used for irrigation.
Efforts to Expand Recycled Water Use
The San Francisco Recycled Water Program includes these projects:
Planning and/or implementation for each of these projects is currently underway and we are evaluating the feasibility of additional projects.