Amid drought, water desalination gets attractive
Interior Secretary Ken Salazar visited El Paso's desalination plant Wednesday to showcase the technology as a way to help alleviate the region's chronic water woes and to support a statewide water supply increasingly stressed by drought and population growth.
The $87 million plant is the largest inland facility of its kind in the world. It takes in brackish water, which has more salinity than fresh water but not as much as ocean water, from an underground aquifer and makes it drinkable. With a daily output of 27.5 million gallons, it's also the largest desalination plant in the U.S.
"Through using water, brackish water, we are able to extend water supply in a way that would have not been possible 10, 15 years ago," Salazar said after touring the facility. "Other places in the country that could learn from this place."
Salazar said desalination is one part of a water management strategy that comprises several factors, including recycling and using water more efficiently.
He toured the facility with Michael Connor, commissioner of the Bureau of Reclamation, and U.S. Rep. Silvestre Reyes, an El Paso Democrat. The plant, named the Kay Bailey Hutchison Desalination Plant, began operation in August 2007.
As such facilities become more efficient and cheaper to operate, they are expected to increase their contribution to the Texas water supply in the coming years, said Jorge Arroyo, director of innovative water technologies for the Texas Water Development Board.
Construction is under way on several other desalination plants, and the state's 50-year plan for water supply infrastructure calls for several more to be in operation by 2060, Arroyo said.
"It's getting more efficient, reliable and less expensive than what it used to be," he said.
Arroyo said desalination is the only option Texas has for bringing "new water" to the state's supply as the readily available fresh water in aquifers and reservoirs is used up. He also noted the stress caused by the record-setting drought in the region.
The plant treats brackish water, which has more salinity than fresh water but not as much as ocean water, to make it drinkable. El Paso's plant uses water from the local aquifer and treats it through reverse osmosis. The method forces water through a membrane, which retains the molecules that make the water unfit for drinking.
Last year marked the most intense one-year drought on record in Texas, and the dry conditions were expected to continue over 2012 because of the La Nina Effect, state climatologist John Nielsen-Gammon said in a recent report. How long the drought could last, he said, was impossible to predict.
Even though weather patterns influenced by oceanic temperatures tend to be cyclical, the "best bet is that global temperatures will continue to increase, causing Texas droughts to be warmer and more strongly affected by evaporation," the report stated.
According to the State Water Plan, desalination is expected to produce nearly 310,000 acre-feet of drinkable water by 2060, said Larry Soward, former Texas commissioner for environmental quality. One acre-foot equals 325,851 gallons.
Improvements in membrane technology, new variations on evaporative-condensation techniques, and other more recent changes have made desalination more cost competitive. However, it is an energy-intensive process and power costs significantly affect the price of produced water, Soward said.
Under the state's water plan, as much as 2 percent of Texas' water supply will come from brackish water by 2060.
"It is my firm belief that despite these projected low volumes and percentages of total supply for 2060, desalination must be on the menu of water supply options if we have any hope of meeting all our water demands in the decades to come," Soward said.
There are plans to convert at least part of the plant's operation to solar power, said Ed Archuleta, El Paso's Water Utility director. He said proposals are being considered and the utility is looking for funds to cover the project's $4.5 million price tag, Archuleta said.
Although desalination is one of the solutions for ensuring the region's fresh water supply, it should not be viewed as a one-size-fits-all approach, said Laura Huffman, Texas director of The Nature Conservancy.
"Desalination is part of a future water supply for Texas and beyond ... (but) it's not a silver bullet," she said.
Conservation accounts for nearly a quarter of the total water supply in the 50-year plan, so thinking of desalination plants as the only solution "undermines years of work by folks that have evaluated local approaches" to conservation, Huffman said.
Aside from the desalination plant and facilities that recuperate sewage to use to irrigate parks and replenish the aquifer, El Paso has implemented an aggressive water conservation strategy over the last 20 years. El Paso has about 700,000 residents, which is about 36 percent more than in 1990, yet the city's water consumption is actually 1.6 percent less than it was that year.
With those measures, El Paso has proven wrong a study that predicted the city would run dry in 36 years.
El Paso's plant in named after U.S. Sen. Kay Bailey Hutchinson, who helped secure more than $29 million in federal funds for the project. It was built through a partnership between the local water utility and Fort Bliss, the local military post.
The guaranteed supply of water the plant provides eased concerns over whether enough water was available to serve thousands of troops the Base Realignment and Closure Commission decided to transfer to Fort Bliss.