Taking Gray-Water Recycling From DIY to the Mainstream

By the touch of a remote, the water going down your shower drain could be diverted to water your garden.

(Photo: Christopher Furlong/Getty Images)

Sep 29, 2015· 3 MIN READ
Kristine Wong is a regular contributor to TakePart and a multimedia journalist who reports on energy, the environment, sustainable business, and food.

Take a shower or do a load of laundry, and you’re most likely wasting some amount of water.

That’s because gray water, the water that ends up in the drain from these sources, can be used to irrigate our lawns and gardens but oftentimes is not.

For residents in the drought-stricken western United States, that could easily change, says Santa Monica resident and self-described tinkerer Garry Sato.

“It’s the way I think most people in our region can participate [in water conservation], be proactive, and not have to suffer,” Sato said.

Sato has an invention he believes gives residents a new way to conserve: a wireless, remote-controlled gray-water system he calls the diverter. The product is the first of its kind to have met requirements for the Uniform Plumbing Code, a stamp of approval needed by plumbers and building inspectors to install for widespread use, Sato says.


Gray-water systems are not new, but they have largely been accessible to those with a DIY spirit—or the money to get a system installed. And despite a reported rise in gray-water system installations in the past year, off-the-shelf products have been limited.

RELATED: Is the Best Way to Beat the Drought Against the Law?

“I decided to make my own [system] because there wasn’t anything out on the market to use at home,” said Sato. “The ones available were mainly for industrial use at refineries, tankers or nuclear subs, and overkill for a household.”

Here’s how it works: The diverter replaces a 14-inch piece of pipe from a home’s existing shower and laundry drainage system that leads to the sewer. Its extra valve-operated opening directs the flow away from the sewer, through the new pipe, and to an irrigation hose—allowing users to water their lawns with the recycled water. The hose can run through the home into one’s yard via a 1.5-inch hole drilled into the side of the house or the foundation, he added.


“The most simple system will involve hooking up the pipe to a garden hose,” Sato said.

Users can open and close the valve—choosing to water or not water their yards—by pressing a button on a portable remote control.

The water conservation implications for such a system are huge. On average, one person uses a few dozen gallons per day for showers and laundry—making up about 60 percent of the water consumed in a household. With the diverter, an average household could save up to 4,000 gallons of water per month.

According to Sato, no other doctoring to the plumbing system or house would be needed for the basic setup. He uses the system to water his garden, moving the hose around to different parts of the yard he wants to irrigate the night before.

But where the water goes is really up to the user. The hose can run to temporary storage tanks designed to filter or disinfect water, then pump it out for either toilet flushing or landscape irrigation.


Local gray-water regulations can also determine how residents set up their system. In California—where the system might be needed most—the plumbing code requires users to follow several best practices, such as not to store gray water unless it is filtered or disinfected first, as it may contain bacteria and start to smell. According to Oakland-based Greywater Action group, gray water isn’t safe to drink but there have been no documented cases of illness in the U.S. transmitted via gray-water systems.

Sato wants California to emulate Tucson, Arizona, which passed legislation requiring that all new construction built after June 1, 2010 be gray-water system-ready—the same way new houses in California are required to have the hookups installed for an electric vehicle charging station.

In July, Sato met with Assemblymember Richard Bloom (D-Santa Monica) about his idea.

“We’re interested in how we can expand the use of gray water,” said Sean MacNeil, Bloom’s spokesperson. “We don’t know what all the options are right now, but considering the drought, now seems like a good time.”

Though his product will be on the shelf in limited release at five Southern California–based Ferguson plumbing stores by early October, Sato is looking forward to late next month, when he’ll demonstrate the diverter for officials with the city of San Francisco.

(Photo: Courtesy Greensmart Sustainable Concepts)

(Photo: Courtesy Greensmart Sustainable Concepts)