National Brackish Groundwater Assessment: How is Brackish Groundwater Being Used?

Science Center Objects

Industry and public drinking-water suppliers are increasingly turning to brackish groundwater to supplement or replace the use of freshwater. Brackish groundwater is either directly used or treated.

 

Direct Use

Brackish groundwater is directly used for purposes such as cooling water for power generation, aquaculture, and for a variety of uses in the oil and gas industry such as drilling, enhancing recovery, and hydraulic fracturing.

Thermoelectric power plant with cooling towers, smokestacks, and transmission towers

Thermoelectric power plant, Euharlee, Georgia.(Credit: Alan Cressler, USGS)

Image: Hydraulic Fracturing Operation Underway

A hydraulic fracturing operation is underway at this drilling pad in the Marcellus Shale gas play of southwestern Pennsylvania. (Credit: Doug Duncan, USGS)

 

 

 

 

 

 

 

Treated Use

For purposes requiring lower dissolved-solids content, especially drinking water, brackish water is treated through reverse osmosis or other desalination processes. In 2010, there were 649 active desalination plants in the United States with a capacity to treat 402 million gallons per day (Shea, 2010). Of the desalination plant capacity in the United States, 67 percent was for municipal purposes, 18 percent for industry, 9 percent for power, and the remaining 6 percent for other uses (Mickley, 2010). A total of 314 desalination facilities are used for municipal purposes, 49 percent of which were in Florida, 16 percent in California, 12 percent in Texas, and the remaining 23 percent dispersed among other states. More than 95 percent of the desalination facilities in the United States are inland (Mickley, 2010), and most facilities are designed to treat groundwater with dissolved-solids concentrations in the brackish range (Shea, 2010). Recent advances in technology have reduced the cost and energy requirements of desalination, making treatment of brackish groundwater a more viable option for drinking-water supplies (National Research Council, 2008).

Map showing desalination facilities in the U.S. (most are located in CA, FL, TX, NC, VA, and the Upper Midwest).

Locations and sources of desalination water at municipal desalination facilities in the United States in 2010.​​​​​​​

 

Amount of Saline* Groundwater Being Used

The National Water-Use Science Project, part of the National Water Census, has published information about saline water use since 1985. The reports include estimates of water withdrawals by State, source of water, and category of use. *Saline water for purposes of that program is defined as water with a dissolved-solids concentration greater than 1,000 milligrams per liter and includes the brackish concentration range.

County map of saline groundwater use in the U.S., with highest use in states like CA, TX, OK, FL, UT, and WY.

Saline groundwater use, by county, in the United States and selected U.S. territories in 2010.

Graph where mining use doubled from 2005-2010; thermoelectric use peak in 2000; public supply and industrial use stay constant.

Saline groundwater use by water use category, 1985 through 2010.