By Chuck Cullom, CAP Colorado River Program Manager
Arizona is in its 17th year of drought, but could salty water be the answer to the state’s water woes? I am part of the Desalination Committee of the Governor’s Water Augmentation Council and we are exploring the potential to use desalination technology to address water needs across the state.
We recently met in Yuma, where we toured the Bureau of Reclamation’s Yuma Desalting Plant (YDP), discussed brackish groundwater in the area, and examined potential costs to develop those resources. While most people think of desalination technology to treat seawater, it is also available to treat brackish groundwater.
So what is brackish groundwater? It’s groundwater that is too salty for drinking water or irrigation uses. To make use of brackish groundwater, it must first be treated in a desalination facility like the YDP.
Treatment isn’t cheap, but it can be affordable. In Yuma, our studies show that there is a long-term supply of approximately 50,000 – 70,000 AF a year available from brackish groundwater in the area that could be treated at the YDP. When you consider that one acre-foot of water will supply two families for a year, you can see it’s a resource with huge potential.
Construction on the YDP was completed in 1992 and it has operated twice since then, so maintenance and upgrades would be needed before the plant would be fully operational. The Bureau of Reclamation estimates it would cost approximately $50 million to address the critical points that would get the plant to operate at 1/3 of its capacity.
Cost isn’t the only thing to consider. Producing fresh water by desalting brackish groundwater creates salty effluent that must be handled in an environmentally responsible way and provide benefits to local water users. The committee is also looking at approaches to minimize environmental impacts.
Arizona has abundant supplies of brackish groundwater for potential development. The committee is looking at a wide range of brackish groundwater resources including in the West Salt River Valley area, Coconino County – Winslow/Leupp areas, Picacho, Wilcox, and Gila Bend areas. The committee intends to gather more information, including potential discussions with water users in the brackish groundwater areas.
The committee expects to have a full report by the end of the year.