Desalination is the process in which minerals are removed from saline water. While several different methods of removal exist, the most utilized procedure within the U.S. is reverse osmosis, or RO. This process forces saline water through a series of membranes that trap the mineral molecules and allow the water molecule to pass through. This method can also be adapted for use in the shale market to deal with the significant amounts of water associated with this technology.
The result of these processes is sterile water, which is, in the case of drinking water, then slightly re-mineralized and distributed within the end user’s water system. In the oil field, this water can be processed to varying degrees to be reused in the fracking process or cleaned up to the point of being used for some other purpose. The highly mineralized waste, or concentrate, is then disposed of by either introducing it back into a highly saline water source such as the ocean or highly saline groundwater, or it is injected into waste injection wells.
Texas is home to several large inland desalination plants. Perhaps the best-known major facility in Texas is the Kay Bailey Hutchison plant in El Paso. Part of the El Paso Water Utilities public water system, it is currently the largest inland brackish water desalination plant in the world. This facility has the ability to produce up to 27.5 million gallons of fresh water daily. This figure represents approximately 25 percent of the water for the region, which not only includes the greater El Paso metropolitan area but also Fort Bliss. The concentrate produced during this process is currently re-introduced into a saline aquifer in the region.
The KBH plant is currently undertaking a project to commercialize the concentrate, separate the minerals and sell that material to an end user. This process creates additional fresh water, thereby increasing the overall efficiency of the KBH plant. The success and viability of this ongoing project could have a far-reaching impact on the desalination process — not just here in Texas but all over the world.
The Southmost Regional Water Authority (SRWA) Brackish Groundwater Treatment Facility outside of Brownsville also uses an RO type of process to treat brackish groundwater. This is the oldest desalination plant in Texas, having come online in 2004. The plant has recently completed improvements that have raised the capacity to 10 million gallons a day. The concentrate from this process is reintroduced into the Gulf of Mexico where it rapidly dissipates. This facility serves the city of Brownsville and an additional four communities in the region.
The newest desalination plant is the San Antonio Water System (SAWS) desalination plant. Current capacity under the first phase of construction will be approximately 12 million gallons per day. After the completion of two more expansion phases, in 2021 and 2026 respectively, the total capacity should exceed more than 30 million gallons per day. Concentrate produced from this facility will be disposed of in an injection well currently owned and operated by SAWS.
While these three facilities represent the bulk of the desalination currently taking place in Texas, there are over 100 different desalination facilities within the state. While many of these are small or have limited operation, there are a number of larger plants currently under construction or in the planning phase.
As an alternative to surface water, desalination is becoming more of a viable option for water planners. The ongoing myth that desalination is too expensive no longer holds water. In Texas, our surface water, for the most part, is accounted for. Many communities and industries must find new water. And while there are a number of planned surface water projects represented in the statewide water plan, the likelihood that all or even any of these proposed projects will actually be built is sketchy at best. Regardless, any “new” water is going to be more expensive than water that was planned for and allocated during the ’60s and ’70s. In this situation, desalination becomes a viable option. It is drought-proof and readily available.
The Texas Water Development Board estimates that there are over 2.7 billion acre-feet of brackish water below our feet; and, of course, the Gulf of Mexico represents an unlimited amount of water that can be utilized.
While desalination is not the only answer, it is part of the answer. Texas continues to grow at an exponential rate. There are many communities that should make use of the brackish water beneath their cities, and those on our coast should be desalinating for both municipal and industrial use. In the future, these water sources will be a critical component of our overall water portfolio. Texas’ water needs will certainly not diminish. Conservation and reuse are also part of the answer, but these methods will only go so far. We will have to develop new water, and desalination must be part of the solution.
About the author: Kyle Frazier is the Executive Director of the Texas Desalination Association, which he co-founded in 2011. He is also active as Kyle Frazier Consulting, Inc. representing legislative and public policy interests for a variety of business clients since 2004—these include water desalination, healthcare, alcohol regulation, and excise and sales taxes. Frazier has been involved in politics and governmental relations for more than thirty years. He studied at Baylor University and has participated in extensive professional development in a number of areas that are of benefit to his clients. He has served as a board member to Keep Texas Beautiful and the Woman’s Advocacy Project.
Photo courtesy of Kyle Frazier