In most places it makes perfect sense to be as efficient with water as possible, but in the desert it is especially true or so it would seem. A group of citizens in Phoenix thought so to. With an average annual rainfall of only 7.6 inches, water conservation is just common sense. Consequently, they wanted to create a standard for greywater reuse in new homes in northeast Phoenix. But the city thought otherwise.

The citizens led by Mick Dalrymple, a spokesman for the U.S. Green Building Council in Arizona, proposed installing two sets of pipes in new homes in northeast Phoenix so residents could reuse some of their wastewater as greywater; immediately saving water and over time money.

However, the city needs the wastewater from the homes in the northeast part of the city to feed its Cave Creek reclamation plant, said Ray Quay, assistant director of the city's Water Services Department.

Phoenix has a master plan for its wastewater, reusing about 95 percent of it, whether for irrigating big green spaces, such as golf courses, or supplying water for the cooling towers at Palo Verde Nuclear Generating Station.

Quay does acknowledge that there are places other than northeast Phoenix where greywater use makes more sense. Those include pockets of town that are still served by septic tanks and, especially, rural Arizona. Phoenix won't block homebuilders from offering greywater as an option, Quay said, but it would rather manage the water itself.

Greywater, a relatively unknown but age-old method of reusing water, has gained new supporters as Arizona has struggled with drought. Scottsdale's green-building program encourages greywater systems. The state Department of Environmental Quality eased the regulations on greywater use four years ago, making it easier to reuse household water. And a bill just signed into law will provide $200 tax credits to homebuilders who add the piping for greywater use.

Additionally, there are fewer restrictions on greywater use since the state Department of Environmental Quality loosened its rules in 2001. Residents must simply follow 13 guidelines issued by the agency. No special permit is required.

Greywater proponents say the idea of reusing household wastewater is a fairly simple concept that critics are making too complex. They point to the bigger picture - greywater cuts down on the infrastructure needed for water systems. The less water people send down the sewer, the broader the area a treatment plant can serve, Dalrymple said. This would reduce the need to build more costly plants.

Related Sites:

Phoenix - General overview of the area including weather, population and other statistics

Guidelines Issues by the Arizona Department of Environmental Quality - Guidelines published by the State of Arizona on greywater systems.

Greywater Central by Oasis Design - Good overview of greywater systems with links to several other related sites.