Arizona Water Resource Newsletter
Water Resources Research Center
College of Agriculture and Life Sciences
The University of Arizona, Tucson AZ


About vol. 12 no. 6 AWR main home pull down menu   Guest View

Tax Credits for Graywater Use Would Boost Conservation

Arizona State Senator Gabrielle Giffords wrote this Guest View assisted by Val Little of Water CASA.

It is common to see newspaper headlines give dire warnings of our drought situation here in Arizona: Can We Weather the Drought?; Wet Week Means Little to Drought; Arizona Farmers Facing Catastrophe; Cities Face Water Limits; We Should Save Water Before Our Future Goes Down the Drain.
From Nogales to Kayenta, the harsh facts behind the bleak headlines make for the stuff of real crises. Arizonans, however, seem to understand neither water’s limits nor costs. Responsible policy makers at all levels should constantly be on the hunt for the most effective, efficient and creative ways to save water as well as to educate the people on the limits and costs of this vital resource.

One effort that has tremendous potential for long-term water savings throughout Arizona is the increased reuse of residential graywater. For non-water experts, this is residential “waste” water also defined as water that has been used in the home except water from kitchen sinks and toilets. Most households waste precious drinking water on their lawns, flowers and irrigation when plants can thrive on used water that contain small bits of compost.

According to Oasis Design (http://www.greywater.net), other benefits of graywater reuse include:
Less strain on septic tank or treatment plant Graywater use greatly extends the useful life and capacity of septic systems. For municipal treatment systems, decreased wastewater flow means higher treatment effectiveness and lower costs.

Highly effective purification Graywater is purified to a spectacularly high degree in the upper, most biologically active region of the soil. This protects the quality of natural surface and ground waters.
Less energy and chemical use Less energy and fewer chemicals are used due to the reduced amount of both freshwater and wastewater that needs pumping and treatment. For those providing their own water or electricity, the advantage of a reduced burden on the infrastructure is felt directly. Also, treating your wastewater in the soil under your own fruit trees definitely encourages you to dump fewer toxic chemicals down the drain.

Plant growth Graywater enables a landscape to flourish where water may not otherwise be available to support much plant growth.

Reclamation of otherwise wasted nutrients Loss of nutrients through wastewater disposal in rivers or oceans is a subtle, but highly significant form of erosion. Reclaiming nutrients in graywater helps to maintain the fertility of the land.

Increased awareness of and sensitivity to natural cycles Graywater use yields the satisfaction of taking responsibility for the wise husbandry of an important resource.

One way for the Arizona Legislature to encourage the reuse of this water source is to enact a tax incentive for homebuilders and property owners that would either include graywater use equipment into the construction of new homes or for homeowners who want to begin using a graywater system. Such a tax incentive will be proposed this legislative year for homebuilders in the maximum amount of $200 per housing unit. Homeowners would be credited 25 percent of the hardware costs for their systems, not to exceed $1,000. Since many houses are not suitable for retrofit at any cost, this tax credit for newly constructed homes would be significantly more affordable and practical.

Drafted legislation would make these incentives temporary, to be in place for no more than five years, with a sunset clause. The idea is to ‘prime the pump’ so to speak; to get homebuilders used to developing plumbing plans with graywater capture as a routine component and to create a demand for this plumbing feature on the part of home buyers. The hardware to plumb a production home for graywater capture would be no more than $200 to $300, and a simple residential graywater system could be less than $500. Also, the cost to purchase gutters and downspouts for rainwater harvesting to is typically less than $400.

There are three important factors in Arizona that bring us to this tax policy recommendation. First, the potential for water savings is significant. Up to 40 gallons per person per day; upwards of 140 gallons per family per day is available for landscape irrigation if all sources of residential graywater are utilized. Fifty one thousand gallons of water a year will irrigate a lot of landscape material.

Second, we find ourselves several years into what The U.S. Geological Survey terms “a multi-year drought that now rivals the worst on record for the region.” Plenty has been written elsewhere about drought, and few are still in denial about its possible duration and the impacts we each may face in the months and years to come.

Third, Arizona is the second fastest growing state in the nation. As in the last several decades we will continue to grow at a rapid pace, with projected growth from 2000-2005 at 14.2 percent. We will likely exceed 6 million people in 2025 and with this growth comes the need for new housing. In 2003 this amounted to between 75,000 and 80,000 new homes constructed in our state.

The State of Arizona, both urban and rural, is facing a “perfect storm” concerning our long-term water supply and all levels of government need to explore and implement conservation measures to ensure our quality of life. The combination of these three realities brings us to advocate for something new, something well reasoned and appealing to all water managers, political decision-makers and to the public.

Enacted legislation to allow for limited graywater tax credits in Arizona would provide us with a practical and low-cost solution to one of our greatest looming problems, even in a limited budget year. This is a forward-thinking opportunity that could significantly improve our long-term water problems, particularly in fast growing urban areas. To track this legislation, do not hesitate to contact your state legislator or visit our website at http://azleg.state.az.us