Arizona is doing much to prepare for drought and the potential shortfall predicted by the Colorado River Basin Water Supply and Demand Study. Conservation efforts have gone a long way. So, too, have the innovative methods of reusing wastewater employed by many Valley municipalities, utilities and businesses.
Water is used in the cooling of power plants throughout the country. Arizona has a unique application that’s been in place since 1973 – Arizona Public Services’ (APS’) Palo Verde Nuclear Power Plant, which is cooled by reused water.
Notes Bob Lotts, APS water resources manager, “Palo Verde is the largest nuclear power facility in the United States and the only nuclear power plant in the world that uses reclaimed water for its cooling.”
Palo Verde is also a zero-discharge plant, meaning it releases zero wastewater, recycling more than 20 billion gallons of effluent each year. This eliminates the need for 70,000 acre-feet of Colorado River water annually.
That’s impressive. So is the fact that 65 percent of the state’s sewage treatment plants distribute treated wastewater for reuse. And, in Phoenix, nearly 100 percent of wastewater is reused.
The Arizona Municipal Water Users Association (AMWUA) reports that its members (Avondale, Chandler, Gilbert, Glendale, Goodyear, Mesa, Peoria, Phoenix, Scottsdale and Tempe) are reusing their wastewater for beneficial uses such as power production, irrigation, recharge and environmental restoration. The Phoenix metropolitan area is a national leader in this area. For example, the City of Phoenix supplied treated wastewater for agricultural irrigation as early as 1932 from the 23rd Avenue Water and Wastewater Treatment Plant! In fact, in addition to reusing all of its wastewater for energy production, crops, wetlands and recharge, Phoenix has a diversified water portfolio relying on different water sources and uses little groundwater; codes have been adopted which require use of water efficient fixtures; significant investments in water supply infrastructure keep the system sound and reliable; conservation awareness programs have been in place for decades and more than 180,000 acre feet of water has been stored underground in depleted aquifers.
And Arizona’s history of using reclaimed water goes back even further than that. In 1926, an activated sludge sewage treatment plant was built at Grand Canyon Village with the specific purpose of providing reclaimed water for non-potable needs. The reclaimed water was used for toilet flushing at El Tovar Hotel, cooling water for the power plant at Grand Canyon Village and water for the area’s steam locomotives. This facility had the distinction of being the first operational water reclamation plant in the United States.
With this history, Arizona is well poised to find innovative solutions to the short-term drought and long-term shortage along the Colorado River. Water reuse is one part of the solution that will serve the state well long into the future.