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October 21, 2014

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Desalination gets a serious look

It isn’t cheap and it requires lots of energy, but fresh water from the ocean might be part of Southern Nevada’s future as other sources dry up

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Brad Doherty / associated press file photo

Containers of raw seawater, right, from the Brownsville, Texas, Shrimp Basin and desalinated water are held by Joe del Rio, operator of the Lower Rio Grande Regional Seawater Desalination Project pilot facility. Nevada might trade desalinated water for river water.

As the West dries up, water managers, politicians and environmental groups alike are searching for an option — any option — to create water.

Recently, desalination has been the popular answer. Even the Southern Nevada Water Authority, which has said the technology is no silver bullet, is considering desalting despite its many challenges.

Last month, Gov. Jim Gibbons made waves when he said he would rather see Las Vegas rely on desalination plants on the Pacific coast than on the controversial planned pipeline to move rural Nevada water to Las Vegas.

Southern Nevada Water Authority General Manager Pat Mulroy has not talked with the governor since he made those comments in Fallon on Feb. 21, but last week she said Gibbons just doesn’t understand how complex it would be to build a desalting plant on the coast of California or Mexico and trade the water it produces for more water from the Colorado River.

“I know that the governor is a rancher himself, and he would probably love to have an alternative for the in-state (pipeline) project,” Mulroy said. “I would love to have an alternative to the in-state project.”

Desalination is sure to be part of the valley’s future water supply, she said, but there are environmental and political challenges to using the technology, which is expensive and uses lots of electricity.

And in the end, Mulroy said, a desalting plant would be useless if drought continues to diminish the Rocky Mountain snowpack that feeds the Colorado River’s flow into Lake Mead, the source of 90 percent of the Las Vegas Valley’s drinking water.

If the lake continues to shrink and shortage guidelines enacted by the seven Colorado River Compact states kick in, Las Vegas would no longer be able to use traded or stored river water.

“When shortages get declared those become impossible to take,” Mulroy said. “All those opportunities either disappear completely or become severely limited in times of shortage. The only thing we can rely on in times of shortage are things that begin in Nevada.”

That’s one reason Mulroy says developing a pipeline or some other native Nevada water source is so important.

“Additional resources we’re trying to develop to protect against a drought would also disappear if we take them as Colorado River water,” she said. “They’re not useful at the time we need that reliability most.”

Another major consideration is the state’s relationship with the six other states, Mulroy said. Because those states were told Nevada was committed to the pipeline project, Las Vegas has been promised the first 75,000 acre-feet of any new Colorado River water augmentation project, such the Drop 2 Reservoir planned for Southern California adjacent to the All-American Canal. An acre-foot of water is enough to supply about two single-family homes for a year. In return, the state must develop an in-state water resource.

“If Nevada were to not develop in-state, its credibility would be so badly tarnished,” Mulroy said. “We (would be) saying, ‘We will not do what all the other states have done.’ It would be viewed very much as a breach of good faith, on Nevada’s part, to rely completely on other states’ resources, particularly during shortage.”

Despite the need to develop water resources that don’t rely on the overstretched Colorado River, the Water Authority is seriously considering desalination in general and an existing desalting plant in Arizona in particular as options, officials said.

Desalination is part of a 2006-07 study of options to augment Colorado River flows commissioned by the seven states. The results of that study are expected to be released within weeks, according to the authority. The study also examined other augmentation options such as cloud seeding and vegetation management.

The study was the first time the authority formally studied desalting, although a spokesman said the option has been discussed informally since 2000.

For now, the authority’s official position on desalting remains that the technology “is not promising as a near- or middle-term option in the face of the drought on the Colorado River ... because it does not reduce our 90 percent reliance on the Colorado River. It has been viewed as more of a longer-term option,” spokesman Scott Huntley said in an e-mail last week.

Mulroy said desalting ocean water could play a role in plans to pump from the eastern Nevada aquifer, the source for the pipeline project. During years when shortage guidelines aren’t in effect, Nevada could rely on desalted water instead of rural ground water to augment its supply.

That would “give us the freedom not to pump in areas of the ground water project if we’re looking to let an area rest for a while,” she said.

The authority in December also began considering use of a plant in Yuma, Ariz., that removes salt from brackish ground water. The plant was built by the Bureau of Reclamation in 1992 to improve the quality of water flowing into Mexico as part of a treaty agreement, but has been mothballed since then because it wasn’t needed.

Although it is too early to determine whether water would be available for Nevada or what the price tag would be, Huntley said that “the initial concept includes an exchange of Colorado River water with Arizona.”

The authority is analyzing the engineering, cost, and environmental and legal barriers to the plan.

The plant could produce 100 million gallons a day, enough water, on average, for about 224,200 single-family households. The plant uses 20 megawatts of electricity when operating at full capacity. It was tested successfully, although not at full power, from March 1 to May 31 last year.

The cost of the plant was equivalent to $250 million today, according to Jim Cherry, Yuma area manager for the Bureau of Reclamation.

During the wetter years when it was being built, the plant was criticized as a waste of money. As the level of water in Lake Mead has changed, so have opinions about the plant.

Cherry said the Yuma plant has served as a technological example for new, successful desalination plants being used around the globe. There are about 13,000 desalting plants operating globally, including 123 in Florida alone, he said.

Advocates agree with Gibbons that it’s time Nevada reconsidered desalination.

“The governor is pursuing 21st-century technology as opposed to the 19th-century pipeline technique,” said Mark Bird, a professor at the College of Southern Nevada and a desalting proponent. He believes a desalination plant in Mexico would be a less expensive option than a pipeline from eastern Nevada.

Mulroy said a Mexican plant is more feasible than one in California, where land prices are high and a strong Coastal Commission has opposed other desalting plants.

Late last year the Coastal Commission approved the $300 million Poseidon Resources desalination plant planned for Carlsbad, Calif., to provide San Diego with drinking water. Environmental groups have rallied against the plant, which has been in the works since before 2000. Opponents complain the plant will be an eyesore and say brine released back into the ocean will kill fish.

Mulroy said it would be even harder to get a plant approved in California if it were intended to ease Nevada’s water crunch.

And no matter the location, cost will be an obstacle.

Desalting is expensive and energy-intensive, according to Peter Gleick, president of the Pacific Institute, an environmental research group based in Oakland, Calif. The institute released a study on desalting in June 2006 that detailed its potential but also the hurdles to widespread use of the technology.

“Conservation and efficiency are cheaper at the moment,” Gleick said. To build a desalination plant and use the water locally costs about $1,000 per acre-foot, he said, or $3.06 for 1,000 gallons.

Take, for example, the desalting plant recently built in Perth, Australia. It cost $357 million. It will desalt more than 26 million gallons of water a day, enough, on average, to serve about 58,300 homes. It also will use 23 megawatts of electricity produced from wind, as much as used by 17,250 average single-family homes.

But the Perth plant — like Yuma’s and the many others like it across the United States and around the rest of the world — also proves that desalination is a feasible option, proponents say.

“This is a country that put a man on the moon, a country with enormous intelligence and financial resources,” said Launce Rake, a pipeline opponent and spokesman for the Progressive Leadership Alliance of Nevada. “We can do this if we have the political will.”

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