Tried drought-proof irrigation?

Cold, fresh water rushes out of the tap. You wash your hands with it. The soap and grime drains away.

Normally, that used water is piped straight to a wastewater treatment facility, where it is filtered, kept in a pond and disinfected ?— all at great expense. But if the ideas of a small-but-growing minority take hold, it could be diverted to water a backyard fruit tree instead.

This is "graywater," a term used to describe water that is not fresh but not toxic either — such as the used water coming from a bathroom sink, shower drain or laundry machine. It's not potable, of course, but plants like it just fine.

With that in mind, why shouldn't residents of single-family homes, especially those living in dry climates like Petaluma's, be watering plants while they do their laundry?

According to James Johnson, a senior environmental health specialist for Sonoma County's Permit and Resource Management Department, graywater is an idea whose time has come. Although the concept has been around for several years — the East Bay's "Greywater Guerilla Girls" were rebelliously installing not-to-code plumbing systems in the late 1990s — California only recently updated its building codes to make it easier to install such systems legally.

According to Johnson, the state updates its codes every three years, and new rules that took effect at the beginning of this year have "given us a little bit more to work with."

Today the regulations include a whole section devoted to graywater, which the state says can come from numerous sources including swimming pool backwash, foundation drainage or cooling runoff from an air conditioner. Such water, once captured, can be stored only briefly and used for specific purposes.

"You can even bring it back into the house to flush the toilet," Johnson said. If done properly, a typical household can reduce water use by about one-third using a graywater system.

In this time of sustained drought, such recycling techniques are considered a good way to recapture precious water. County leaders know this, Johnson said.

"My director came to me, about two weeks ago, and he provided the Board of Supervisors update that tells people in the county what's going on," Johnson said. Their motto: "Retain it! Don't drain it!"

According to the county's website, "We can respond to the drought by installing graywater systems in our yards to irrigate plants and keep them thriving."

The City of Petaluma has been on board with this plan from the start, due in no small part due to Daily Acts, a nonprofit group headquartered downtown. Dedicated to furthering sustainability in the city and county, the group has been spreading the word about graywater for years.

Indeed, Trathen Heckman, the group's founder and executive director, "installed the first permitted single-family-residence graywater system in the county, way back in 2009," said Daily Acts program coordinator Ryan Johnston.

That was in his home near 8th and G streets. Soon after, a few neighbors took up the idea, then a few more. Today, Johnston said, more than 30 Petaluma households are using the simplest type of graywater system – basically a pipe or hose diverting used water from the laundry machine to landscaping outside.

In Petaluma, such a system requires no permit and is easy to install with about $150 worth of materials. The city has "a really wonderful incentive program," Johnston said, in which it will give interested residents all the parts necessary, free of charge, "to install a laundry-to-landscape graywater system."

Daily Acts then follows up with residents to make sure they're able to install the system properly.

By some estimates, a typical family of four uses at least 7,000 gallons per year on laundry alone — meaning that a few hundred Petaluma families switching to graywater would save millions of gallons per year, while also relieving the city's overburdened water treatment facility. In both cases, water and sewer rate payers can save money.

Such a setup "recharges groundwater as well," Johnston said. "It's putting back into the piggy bank that we're drawing out so heavily." He also recommended that residents remove thirsty lawns and plant gardens instead (graywater is not appropriate for vegetables where the water touches the food directly, such as carrots, but is perfect for woody perennials and trees).

Carrie Pollard, principal program specialist for the Sonoma County Water Agency, remains optimistic on the prospect of recycling water at the single-family-home level.

"I would say graywater is more predominant in Sonoma County than in other regions. But there's definitely an opportunity for expansion," she said. And as Sonoma County weathers a years-long drought, "This is a source of water that's readily available."

Pollard is co-chair of the Qualified Water Efficient Landscaper, or QWEL, program, which offers training to contractors, plumbers and landscapers in "how to appropriately manage landscapes." A subset of that training is installing graywater systems.

Anyone can take advantage of the several-day, 10-hour program. "We do have homeowners come and participate in all of our classes," she said. Those interested can sign up at qwel.net.

These are all baby steps, perhaps. But from the perspective of someone who's been following the movement from the beginning, graywater has come a long way.

"Compared to what it was and what it is now, it's totally different," said Laura Allen, an Oakland resident and one of the original Greywater Guerrillas.

Today, for example, "You can legally install a graywater system with no permit," she said, referring to the basic laundry-to-landscape model.

Allen praised both county efforts and Daily Acts. She also spoke highly of cities like Petaluma, which "has a really great rebate program," she said.

It seems some local leaders have come to realize that, in the long run, "It's cheaper for them to provide an incentive program than to buy more water," Allen said.