Grey Water Will Irrigate Golden Gate Park, Golf Courses
By Thomas K. Pendergast
To decrease San Francisco’s dependency on the Hetch Hetchy water system, which
delivers water from the Sierra Nevada Mountains, the SF Public Utilities Commission
(SFPUC) and the SF Recreation and Park Department are in the process of switching to
“recycled” water for irrigating Golden Gate and Lincoln parks and the Presidio.
The water will be used strictly for watering lawns and bushes, filling lakes and the like,
but will not be for the public to drink.
Currently, the department uses a combination of drinking water and ground water for
irrigation, but the ground water is increasingly being used to supplement the drinking
The $214 million project includes construction of a new recycled water treatment facility,
which will be located within the boundaries of the commission’s Oceanside Wastewater
Treatment Plant, which sits just south of the San Francisco Zoo, and the construction of
almost eight miles of new pipelines under city streets to convey the recycled water to
The project also includes the construction of an 840,000 gallon underground reservoir,
and an above ground recycled water pump station in Golden Gate Park. The pump
station will also transport recycled water to Lincoln Park and the Presidio.
Construction began in early 2017 and recycled water deliveries are scheduled to begin in
The funding is coming from bond money, including the $4.6 billion Water System
Improvement Program and Water Enterprise Bonds.
The plan was first introduced in 2010, except back then it was with the water treatment
plant located near the western end of Golden Gate Park. This raised a host of concerns
among local activists and neighbors, who pointed out that the SF Recreation and Park
Department was attempting to evict the Haight Ashbury Neighborhood Council (HANC)
recycling center out of the park because, so the argument went, the park’s Master Plan
expressly forbids construction of facilities for “industrial use.”
So, rather than keep the recycling center in the park, city planners decided to
look for an alternative location for the water treatment plant.
Suzanne Gautier, a representative of the SF Water Department, said opposition
to the Golden Gate Park site motivated the SFPUC to move it.
“We went back and revisited all of the potential sites that had been explored during
the initial process, and there were several options explored and … the determination
was made that the Oceanside Plant provided unique opportunities, one of which is it’s
within the footprint of the property so there would be no impact to a neighborhood
because of the building of a recycled water facility,” Gautier said. “It’s right there inside
The plant now treats residential wastewater from the west side of San Francisco, which
goes through several treatment processes to produce “secondary effluent,” which is then
discharged into the Pacific Ocean.
The new recycled water treatment facility will take a portion of this secondary
effluent flow prior to its discharge into the ocean and treat it further with membrane
filtration and reverse osmosis. The recycled water will then be disinfected with
ultraviolet light prior to being delivered for irrigating the Golden Gate Park and the
Lincoln Park and Presidio golf courses.
The water produced by the state-of-the-art treatment technologies is known as
“advanced” treated recycled water, according to the SFPUC. Reverse osmosis removes
salt, nutrients and ammonia from water.
The treatment technology was selected for the Westside Enhanced Water Recycling
Project because the primary uses of recycled water will be for irrigation and filling
lakes at Golden Gate Park.
According to the SFPUC, using the higher level of treatment will minimize the potential
impacts of salts (sodium, chloride) on park vegetation, and of nutrients (nitrogen,
phosphorus) and ammonia on park lakes.
The goal is to save potable water currently used for irrigation and other nonp
non-potable applications. The commission says this will make the drinking water
supply less vulnerable to risks, like earthquakes and droughts, while helping meet
the City’s long-term needs .
Barbara Palacios, an engineer and project manager with the SFPUC, said project
overseers are aware of the concerns about cross-contamination with the water
used in drinking fountains throughout the park and already have a plan to deal
“Part of the changes would be to disconnect those areas f rom the potable system, so
once they are connected to the recycled water system they will be disconnected from the
potable system and we would undergo an extensive series of testing to make sure that
the two systems aren’t what we call ‘cross-connected,'” Palacios said. “There’s a cross-
test that we have to perform that will be overseen by our own internal folks as well
as regulators, to demonstrate that they are completely separate. ”