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 State Water Resources Control Board. 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
- Decorative fountains and water features
- Soil compaction and dust control
- Street cleaning
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 no longer meet the new State standards for irrigation use.
Current Use of Recycled Water
The SFPUC partnered with Daly City to construct infrastructure, produce and deliver recycled water to irrigate Harding Park and Fleming Golf Courses. Since 2012, recycled water produced by the North San Mateo County Sanitation District, a subsidiary of Daly City, has been used to irrigate the golf courses. This project was awarded $2.1 million in Proposition 84 grant funding for a portion of the construction costs.
The Pacifica Recycled Water Project was developed and constructed through a partnership between the SFPUC and the North Coast County Water District (NCCWD). Recycled water deliveries from the NCCWD began in 2014 to irrigate the eastside of the Sharp Park Golf Course in Pacifica (a retail water customer of the SFPUC), and other nearby areas. This project was awarded $2.3 million in Proposition 50 grant funding for a portion of the construction costs.
Efforts to Expand Recycled Water Use
The San Francisco Recycled Water Program includes these projects: