La Verkin • As Washington County continues its rapid growth, water officials want to know if desalinating local salty hot springs for drinking water could make sense for the future.
On Feb. 3, board members for the Washington County Water Conservancy District approved a contract to spend $550,000 for a feasibility study to explore if the district could desalinate the La Verkin Hot Springs it acquired on the Virgin River in 2013 after a protracted legal battle with the previous owner who went bankrupt.
If the study conducted by Woods Cross-based Ampac USA shows that the company’s advanced desalination technology works and that removing the salt from the river makes economic sense, it could eventually enable the district to tap more of the spring water for drinking and irrigation.
Just how much drinking and irrigation water desalination might yield, district spokesperson Karry Rathje said, is unknown at this point. “That’s one of the reasons why we are doing the study, so we will have that [information],” she said.
Currently, the district diverts water upstream of the hot springs for drinking and irrigating crops such as fruits and vegetables. Water downstream from the springs is so salty its use is largely confined to growing alfalfa in Washington Fields, according to district officials.
Getting the salt out
All told, the district’s springs — also known as La Verkin Sulphur Springs, Dixie Hot Springs or Pah Temp — produce roughly 7 million gallons of 107-degree hot water per day, according to the water conservancy district. That equates to roughly 5,000 gallons per minute.
Moreover, according to district officials, the springs release 109,000 tons (enough to fill over 6,800 semitrucks) of salt per year. That makes the springs 20 miles east of St. George the fourth-largest salt contributor to the Colorado River system. Only Blue Springs, Glenwood Springs and Paradox Valley, all located in Colorado, release more salt and minerals into the river system, according to the U.S. Bureau of Reclamation.
That salt content, which renders the water unfit for drinking and irrigating some crops, would pose a problem for a desalination plant in a landlocked state like Utah, which must find places to put the salty brine stream. Other drawbacks that have hurt past proposals to desalinate the Colorado River and its tributaries is the process is prohibitively expensive and the reverse osmosis technology that removes the salt uses massive amounts of energy.
“Since the 1970s, the Bureau of Reclamation and the U.S. Geological Survey have conducted studies on the hot springs over the years to decide whether or not the federal government should step up and desalt [the rivers],” district assistant manager Brock Belnap said. “And the answer has been … it was just too expensive.”
That’s where Ampac USA enters the picture. Belnap said the Utah company has some cutting-edge technology it wants to test to see if it could be employed to desalinate the roughly 100 hot springs the district owns along a 1,500-foot stretch of the Virgin River and make it cost-effective.
Low-risk, high-reward
Santa Clara Mayor Rick Rosenberg said the best part about the Ampac is that regardless of whether or not desalinating the hot springs proves feasible, the district and area taxpayers won’t have to foot the bill. The Utah Division of Water Resources is pitching in $300,000 for the study and Ampac is contributing $250,000.
“We’ll get the results of the study, which should be really interesting, and it will answer questions [about desalination] that people have been asking for over 25 years,” said Rosenberg, who sits on the district board.
As for what Ampac gets out of conducting the study and helping pay for it, district officials presume that if the company can show that its cutting-edge technology works, it could pave the way for more desalination business.
Ampac officials did not respond to requests for comment.
Belnap said Ampac’s study will not involve setting up a desalinating plant at La Verkin Hot Springs. Instead, the company will take water from the springs and conduct the tests at its lab. Aside from demonstrating if the technology works, the study must also determine if the salt in the brine stream can be dealt with in a cost-effective and environmentally sound manner.
District officials say disposing of the concentrated brine stream that results from desalinating has traditionally been a major challenge. One proposal would be to put the brine byproduct in large, shallow drying beds, but Belnap said that would require multiple acres of land.
Zero liquid discharge is another potential solution. Belnap says the process involves big industrial plants using heat to evaporate the water so the brine is concentrated down to salt, which carries a high energy cost and would require creating a landfill to store the salt.
Another idea often bandied about is for the district to give the salt to the Utah Department of Transportation for use on the roads during the winter. But Belnap said the huge volume and toxic nature of the salt desalination would generate could be problematic.
“It is so corrosive,” he said, “that UDOT wouldn’t want to put it anywhere … because it would tear up the roads,” he said.
Yet another suggestion is to inject the brine stream deep into the ground, something which is being done at Paradox Valley. But Belnap said that has produced some earthquakes up to 4.0 on the Richter scale, so that is a no-go for Washington County.
Ampac’s study is expected to get underway soon and take about a year to complete, according to district officials.
