In 2018, the United States Geological Survey reported it estimated there was 680,000,000 acre feet of brackish water under Arizona. That represents what Arizona uses in 100 years. This water was left between 500 and 1,500 feet under the surface of the state millions of years ago when an ocean covered what is now Arizona. 

Brackish water is not as salty as seawater, but it is more so than fresh water. It is found in geological layers lower than fresh water and does not mix with it. Brackish water costs about 50% less to desalinate than seawater. The state has a giant desalinization plant in Yuma that is hardly used and a huge atomic reactor outside of Phoenix that can make it potable/drinkable. The state could choose to make more desalinization plants. 

Untreated brackish water can be used for industrial and non-industrial uses, such as fire control, power generation, cleaning, and even some kinds of irrigation. Brackish water can be used to supplement water needs to help endangered species that require brackish water to survive in coastal regions. It is critical to help maintain ecological balance of these coastal ecosystems. Other uses include aquaculture, mining, cooling (e.g., nuclear power plant, etc.), groundwater recharge, and to help industries use less freshwater and reduce wastewater production.  Brackish water can contain minerals and rare earths that can be used to create solar panels, hydrogen fuel cells, and wind turbines as well as other technologies. 

Brackish water also comes out of the ground when oil and/or gas is extracted from the ground. This water again was deposited millions of years ago when the region was covered by ancient oceans.

Currently, there are about 1,000,000 petroleum wells in the country that produce around 58,000,000 barrels of brackish water every day (7800 acre feet/2,236,000,498 gallons).  The brackish water and oil/and or gas reach the surface mixed and must be separated through a process often conducted by tanks close to the well.

Petroleum companies view brackish water as a burden. They have no use for it and must find ways to dispose of it. The brackish water is extracted and is eventually trucked to a “disposal well.” A well that has been pumped dry of its oil and gas. The brackish water extracted from other wells is pumped down the disposal well to “dispose” of it.

Arizona could decide to provide petroleum companies another way to get rid of their unwanted brackish water. They could use the gigantic national underground pipeline system that is connected to every state in the continental US to send brackish water to Arizona.  The petroleum companies could even use their current pipeline easements to construct dedicated brackish water pipelines to Arizona. It would be a win-win. The petroleum companies could get rid of a burdensome byproduct, and Arizona could access an almost unlimited source of water.

There are many potential uses of untreated brackish water. However, there is a serious need for potable drinking water in the state. How could we desalinate this water in a cost-efficient way? Currently, there are four methods of desalinating brackish water: 

• Reverse Osmosis – Using a membrane to remove salt.
• Electrodialysis – Using electrified membranes to remove salt.
• Ion Exchange – Using an electrified resin to remove salt.
• Distillation – Boiling brackish water to remove salt and collect the fresh water condensate. 

Salt recovered from the desalination of brackish water could be sold on the international salt market, which represents a $34,000,000,000 yearly business. These funds could help the state overcome budget shortfalls, and fund public infrastructure projects, among other things. 

The Arizona Legislature is expected to vote to determine if the state should fund serious study of the potential of using brackish water for solving at least part of our water crisis. It is my sincere hope that it makes a wise informed decision that includes brackish water as part of the solution.

Kevin Blake is a Tucson psychologist in private practice who has managed a family farm and oil and gas operation in Oklahoma for years.