Water is a precious resource in the Southwest, and APS' facilities strive to minimize water usage through a variety of water-conservation activities and through use of treated effluent as a water source. In fact, 61 percent of all water used by APS is treated effluent as discussed in the section below. APS' major use of water is in electricity generation. 

Our SunCor affiliate also has numerous water conservation efforts in place, which are discussed in the Subsidiary section of this report.

New Water Resources Management Department Formed at APS
Recognizing the increasing importance of water resources in our sustainable energy future, in 2008 APS formed a new corporate Water Resource Management Department. This department will coordinate water resouce planning and strategy to ensure a sustainable and cost effective supply of water in order to provide reliable energy for APS customers. 

Use of Treated Effluent
One of our major water conservation methods is to use treated city wastewater for our water source in power generation at our Redhawk and Palo Verde power plants.  APS is one of the largest users of treated effluent for power generation in the United States. This significantly reduces the amount of potable surface and groundwater required in our generation activities. As shown in the chart below, in 2008 over 61 percent of our total power plant water came from treated effluent. At the Palo Verde Nuclear Generating Station and our Redhawk natural gas-powered facility, we use treated effluent purchased from seven cities in the Phoenix metropolitan area for cooling. A 35-mile pipeline carries treated waste water from the City of Phoenix and Tolleson sewage treatment facilities to Palo Verde, where we use an advanced waste-water treatment process capable of preparing 90 million gallons of water each day for use at both Palo Verde and Redhawk.

Each year, Palo Verde's water reclamation facility processes about 21 billion gallons of treated effluent for power plant use, preserving enough potable water for about 75,000 homes.

The above chart is based on a total water use of 37,239 million gallons (114,283 acre-feet) in 2008.

Another way in which APS conserves water is through careful water chemistry and treatment. This allows for a high level of water recycling in our electricity-generation process. We reuse our water supplies as much as possible to avoid wasting water, however, some water must be discharged (this is called "blowdown water") to control the salinity of the water used in the power plant processes.

Water use was also an important consideration in the design of our newest power plants, and APS strived to incorporate water conservation measures in these new plants, resulting in power plants that utilize less water per MWh generated.  The type of cooling system used in new plants is critical to the amount of water used, and APS is committed to using dry or hybrid cooling in new power plants whenever feasible.

Other Water Conservation Efforts & New Voluntary Water Metric
In 2008, APS created a new voluntary internal water use metric and goal for our owner-occupied, non-generation facilities:

•  To reduce the number of gallons of water used annualy per square foot of building space by 1percent per year each year through 2013. 

The year 2007 was our baseline with 34.55 gallons/square foot.  The 2008 Goal was 34.2 gal H2O/sqft. APS Facilities achieved that goal with an end-of-year result of 31.63 gal H2O/sqft.  This was achieved through efforts such as:

APS also incorporates water conservation and use ideas into facility building and maintenance as part of our voluntary participation in the LEED program, which is discussed further in the Materials & Supply Chain section of this report.