Urban farmers have for years installed illegal irrigation systems that recycle laundry and other “gray” water for landscape, but now The City is pioneering efforts to kick it into the mainstream.
Graywater irrigation is often referred to as “guerilla gardening” because state law in 2002 prohibited homeowners from building their own systems without a permit, among other limitations. But in January, the law regulating the reuse of shower, bathroom sink and laundry water was relaxed and discretion was mostly left up to local agencies.
Now officials at the San Francisco Public Utilities Commission are encouraging residents to try their legal “laundry to landscape” pilot program. It offers hands-on workshops and an installation kit that costs about $15 with rebates and tax.
The kit provides all the essential pieces to connect a plumbing system to the washing machine, with manual valves and switches that control water circulation throughout the yard. The water would otherwise be sent to a wastewater treatment plant, then likely to the Bay.
The use of graywater helps reduce the use of what is mostly pristine, Hetch Hetchy snowmelt water for irrigation.
“I can’t believe regular people like me can do this,” said Judy DeMocker, who hoped to finish her system Sunday after securing all the nuts and bolts over the course of what she estimated was three days.
DeMocker’s system was particularly challenging because her machine is on the top floor of a three story unit, and her backyard has a small upward incline. The system relies on gravity, but she was confident the drop from the third floor would give the water enough momentum to push through the 140 feet of piping and up the slope.
“I have about four loads I’ve been saving up for when it’s ready,” said DeMocker, who uses a special, non-chemical detergent and plans to shut the graywater system off for bleach loads.
Babak Tondre, a member of the Greywater Alliance, which formed in 2009 and helped SFPUC with its efforts, said the restrictive laws from 2002 helped prevent cross contamination in water systems.
“Anytime you cut your existing plumbing you are altering a code- compliant system. With the ‘laundry to landscape’ program, you don’t have to cut,” Tondre said.
Tondre said SFPUC is pioneering graywater efforts in the Bay Area, but warned that residents should know that laundry to landscape is not for everyone. He listed several factors to be considered, ranging from the types of plants that are being irrigated to how often the machine is used.
“It’s really a case-by-case system,” he said.