SF Aims To Expand The City’s Recycled Water Supply

As California continues to face drought conditions, a San Francisco supervisor on Tuesday proposed legislation that would not only conserve water but would also expand the city’s recycled water supply.

The ordinance, drafted by Supervisor Rafael Mandelman, would require all new large buildings in San Francisco to double the amount of water collected and reused and also calls for the San Francisco Public Utilities Commission to develop a plan to expand the city’s recycled water supply.

“The climate crisis is upon us, and prolonged drought and annual wildfires have become sad and scary facts of life in California,” Mandelman said during Tuesday’s Board of Supervisors meeting. “Even as we accelerate our path toward a zero-carbon future, we have to prepare now for the reality of extreme water scarcity in California that we know is being driven by climate change,” he said.

Mandelman’s proposed ordinance would expand the city’s 2012 Non-Potable Water Ordinance that requires the collection, treatment and reuse of graywater, which comes from showers and bathroom sinks for non potable uses like toilet and urinal flushing and irrigation in large buildings. It would also require large commercial buildings to treat and reuse black water from toilets and kitchen sinks and expand the required use of treated graywater in residential and mixed-use buildings to include laundry rooms.

The expanded requirements would only apply to new buildings that filed permits starting on Jan. 1, 2022 and would exclude 100 percent affordable housing and permanent supportive housing projects.

The SFPUC is backing Mandelman’s ordinance, estimating the changes could bring the amount of indoor potable water saved in residential buildings and mixed-use buildings to 30 percent while also offsetting as much as 75 percent of total indoor potable water demand for commercial buildings.

“When the Non-Potable Water Ordinance first passed, it was an innovative measure that set a national standard for water reuse practices in new developments,” SFPUC Acting General Manager Michael Carlin said in a statement. “But we know that there is always an opportunity to expand these measures, especially as we contend with this extended dry season.”

Mandelman’s ordinance also calls for the SFPUC to develop a plan outlining additional ways to expand the city’s recycled water supply, including purified water for drinking. The proposed ordinance comes as California Gov. Gavin Newsom declared drought emergencies in 41 counties, including Sonoma, Alameda, Solano and Contra Costa counties.

Less than two weeks ago, the SFPUC called for its irrigation customers and city departments to voluntarily reduce their water use by 10 percent, as the SFPUC’s water reservoirs are currently filled at 76.8 percent of their maximum storage capacity — slightly lower than the historical average of 81 percent around this time of year.

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