Pam Hartwell-Herrero is making sure she washes her family's clothes when the olive tree, rhubarb and coffee berries in her front yard look thirsty.

Rebecca Newburn displays some of the piping used in her graywater system. (Photo: Carlos Avila Gonzalez / The Chronicle) Why?

Hartwell-Herrero and a team of fellow water conservation enthusiasts recently installed a "laundry to landscape" graywater system at her 1960s Fairfax bungalow. It took most of a day to attach a special valve, punch a hole in her garage wall and set up the pipes leading from her washing machine to the garden.

But now, every time Hartwell-Herrero fires up a load of whites, the plants perk up.

"It's hilarious," said Hartwell-Herrero, 40, executive director of Sustainable Fairfax. "With every load we run, my husband, daughter and I run outside to see the water going into the garden."

The idea of using graywater - defined in California as the wastewater from showers, bathroom sinks and washing machines - isn't a novel one. But last month, California followed Arizona, Texas and other states in adopting new graywater standards. Officials with the state Department of Housing and Community Development, which oversees graywater, changed the state code in the wake of recent legislation calling for a re-evaluation of graywater use and Gov. Arnold Schwarzenegger's June proclamation of a statewide drought.

Whereas California property owners previously were required essentially to install costly mini leach fields (those are usually associated with septic systems) and obtain pricey permits, the new codes allow residents to install basic, relatively inexpensive graywater systems themselves with no permits.

Under the old regulations, a graywater system cost as much as $10,000, versus as little as $200 now.

To ensure safety, the water cannot stagnate, run into a neighbor's yard or directly touch fruits or vegetables. In addition, pipes must be several inches underground or under mulch- experts say that is better than burying the pipes deeper underground because rich topsoil is a far better filter of particles, soaps and other materials.

The previous codes "missed the mark in terms of using graywater as irrigation," said Doug Hensel, deputy director of codes and standards for the department. "Hopefully this will streamline the process and will be something else we can use to save water in California."

Amid a third dry year, widespread water rationing, a booming population and concerns about climate change, water use in California is being scrutinized like never before. Many in the environmental community, in particular, argue the state can save its way out of the water crisis by employing water conservation, recycling of graywater and capturing storm water that now runs down city sidewalks and ultimately to the ocean.

Hensel's agency estimates a typical household could save 22,000 gallons of water each year from a laundry graywater system alone.

That opportunity isn't lost on Bay Area consumers. Many are turning to Greywater Guerrillas, an Oakland volunteer outfit that, for the last decade, has advised homeowners on reusing water. Until now, much of the group's work technically fell on the wrong side of the law. Now the group hopes to reach a larger audience.

It was a Guerrillas' class that learned about and assembled Hartwell-Herrero's home system. The group has more classes planned this fall in Walnut Creek and Hopland (Mendocino County).

"We're definitely getting a lot more interest since the drought," said Laura Allen, co-founder of the group.

By some estimates there are already 1.7 million graywater systems at work in California - the vast majority without permits. Nationwide, there are about 8 million, according to Art Ludwig, a Santa Barbara environmental designer and leader in the graywater field.

Ludwig believes that number will only grow as more states grapple with the reality of water shortages, the problems posed by industrial agriculture and the shift toward what he describes as a more direct connection with the land and other precious resources.

"When you're in a city and your water comes from the Sierra or wherever, you don't necessarily care what you're pouring down the drain," Ludwig said. "But when you're doing graywater and watering your citrus tree, you care."