If The City used recycled wastewater to irrigate open spaces just on its western side, it could save about 4 million gallons every day of what’s mostly potable Hetch Hetchy snowmelt.
Wastewater that’s usually poured into the ocean after it’s chlorinated at the Sunset Reservoir could be redirected to a new $108 million recycled water facility most likely going to be built at the western edge of Golden Gate Park.
That’s where more waste would be removed, reverse osmosis would desalinate it and ultraviolet rays would disinfect the water before it’s pumped back through park pipes, giving it two levels of treatment better than what state health guidelines require for recycled wastewater.
It’s a relatively small chunk of the San Francisco Public Utilities Commission’s $4.4 billion water improvement plan that involves building a new treatment facility near the Oceanside Wastewater Treatment Plant, built in 1993 off Great Highway near the San Francisco Zoo.
It’s also part of the SFPUC’s goal to put a cap on the amount of water it imports by 2018, by relying on local water for the increasing demand and tapping into groundwater, treating it and mixing it with drinking water that’s now 80 percent snowmelt.
After the center is constructed — most likely at the same place where one was shut down in the 1990s in between the Beach Chalet soccer fields and Murphy’s Windmill — the SFPUC will replace visible pipes with purple ones used for recycled water and warning signs.
“We’ll have to let people know they can’t drink it,” SFPUC spokeswoman Suzanne Gautier said.
The Recreation and Park Department is the SFPUC’s biggest customer, as it’s responsible for roughly 2 percent of The City’s water consumption every year.
Harding Park Golf Course is in the middle of a plan to use Daly City’s recycled water for its irrigation, and Sharp Park Golf Course, run by The City but located in Pacifica, is dong something similar.
The open spaces on the western side will be the first in The City to use recycled water for irrigation.
Shawna McGrew, who used to work at Sunset Playground, which will use the system that could be in place as early as 2012, said she uses her own recycled water and encourages SFPUC’s efforts.
“I recycle all my water that I do the wash with,” she said. “I use special soap. It’s a hassle, but you know what I think? It’s a great way of saving water.”
Total water used by Rec and Park Department, 2008-09
Total water used in Golden Gate Park, 2008-09