Why Palo Verde, the country’s largest nuclear plant, is cutting its wastewater use

PHOENIX – There’s something in the Buckeye groundwater – a high mineral and salt content – that makes it hard to use, but the Palo Verde Nuclear Generating Station wants to tap into that source to reduce the amount of more valuable wastewater it now uses to cool the plant’s three reactors.

The plant uses millions of gallons of treated wastewater, with much of it coming from Phoenix’s 91st Avenue Wastewater Treatment Plant. Heat from nuclear reactions boils water into steam, which turns the turbines that generate electricity. The steam then must be cooled and condensed. Palo Verde is looking for additional water sources to reduce its wastewater use by 20%.

“Water sources that we’ve been looking at are poor-quality groundwater sources that come from the Buckeye waterlogged area,” said Jeffrey Brown, senior consulting engineer for Arizona Public Service, which operates the plant. “We are able to use some of that water instead of effluent (wastewater) because of the tertiary treatment system that we have here at Palo Verde” to remove the salts and minerals.

Water is vital for the generating station because it’s in the desert, about an hour’s drive west of Phoenix. Despite being nowhere near a large body of water, Palo Verde, which is owned in part by Arizona Public Service, is the largest nuclear generating station in the country by net generation. The scale of the production shows in the amount of water used every minute.

Video by Madison Staten/ Cronkite News

“In the winter, we can use up to 40,000 gallons per minute, and that makes up for the evaporation rate of the cooling towers at the nuclear plant. In the summer it’s more, it’s up to 60,000 gallons per minute,” said Rick Lange, the plant manager of Palo Verde Water Resources.

Sandy Bahr, director of the Sierra Club’s Grand Canyon Chapter, believes the real issue isn’t the source of the water but the volume of water the plant uses.

“The utilities say, ‘Wow, OK, we are using the treated wastewater,’ like somehow it’s not a big deal that it’s using so much water,” she said. “Treated wastewater can be used for all kinds of other things, including habitat restoration. So it is water that is not available for other use.”

Now, Palo Verde is looking for additional water sources to cut down on increasing costs for wastewater and to conserve water.

“It’s increasing our power costs,” Brown said. “Our objective was to come up with programs that we could run to replace that effluent with more affordable water sources.”

The idea to use even dirtier water stems from a partnership with Sandia National Labs, a national nuclear research and development laboratory in New Mexico. Researchers at the lab have created models that identify areas of improvement for Palo Verde.

This waterfall moves treated wastewater into one of two reservoirs at a rate of 50,000 gallons per minute to supply water to cool the nuclear reactors at Palo Verde. (Photo by Alicia Moser/Cronkite News)

“We created the partnership because of objectives that we had regarding the production and cooling costs for power operation here in Palo Verde,” Brown said. “One of the things that increases disproportionately is the cost of cooling, which is related to the water that we use.”

The facility wants to implement the use of this dirtier water within the year.

“We already have funding and sightings for the wells,” Lange said. “We just need approval from the state, and we’re working with the state and the farmers in the area to work through issues and get that in place. We plan on this year being able to start pumping water and that will test all these systems.”

Palo Verde plans to continue conservation efforts through the development of additional cooling technology and its continued exploration of other water options.

“You’re going to come back five years from now and work you’re going to say, ‘Wow, you’re using a lot less of that sewage water because you’re being more efficient and you’re coming up with worse, worse sources of water that can meet your needs,’” Lange said.

This story is part of Elemental: Covering Sustainability, a multimedia collaboration between Cronkite News, Arizona PBS, KJZZ, KPCC, Rocky Mountain PBS and PBS SoCal.

At least 2 well-metering bills at Arizona capitol

Multiple bills in the Arizona Legislature are tackling well metering due to the lack of groundwater regulation outside of central Arizona.

This comes after a series of recent reports in the Arizona Republic showing large industrial farms in rural counties are drilling deeper wells, but these companies are not required to disclose exactly how much water they are pumping.

Rep. John Kavanagh (R-Fountain Hills) is proposing a bill to let the director of the Arizona Department of Water Resources require a meter on wells outside of “Active Management Areas,” which govern the central part of the state. The director could also require an annual report.

Kavanagh said it’s the first step in addressing overuse.

“Everybody’s saying we don’t have the information. So this gets the information,” he said. “Then nobody has an excuse not to act. People can’t be willfully blind in the face of a possible impending water crisis for some residents of our state. And I feel sorry for those residents.”

Meanwhile, a bill from Kirsten Engel (D-Tucson) would simply require well meters outright for large-scale irrigation.

Kavanagh said he had not spoken to House Speaker Rusty Bowers (R-Mesa) about his bill and didn’t know if he supported it. Bowers told the Associated Press last week he was concerned about overdrafting.

“If nothing else, this will start the conversation and maybe it will cause this to be placed into one of the other water bills that are moving forward,” Kavanagh said. “But you can’t stay willfully blind. There’s no excuse for that.”

Rep. Regina Cobb (R-Kingman) said she will soon propose a bill to create an additional regulatory tool called a rural management area.

“I don’t even want to reduce agricultural growth if it can be recharged. If it’s not recharging, we’ve got an issue. If it’s taking away from municipalities that have been there already, we’ve got an issue. If it takes away from their growth and development, we’ve got an issue,” she said. “So we have to look at all those parameters and come together with a decision for that community. And I think that’s where a rural management area works.”

Lower Colorado River Basin Can Still Expect Water Shortage Next Year

PHOENIX – The Lower Colorado River Basin does not avoid a shortage in 2020 despite the plentiful snowpack on the Rocky Mountains this past winter.

Why? Well, the new Drought Contingency Plan defines different “tiers” of shortage. The Lower Basin will not drop into a Tier One shortage next year because Lake Mead will almost certainly remain above 1,075 feet in elevation.

At the same time, Mead will likely remain under 1,090 feet. That triggers a Tier Zero shortage.

“Under Tier Zero conditions, Arizona takes a reduction of 192,000 acre-feet in its annual Colorado River entitlement,” said Suzanne Ticknor, assistant general manager at the Central Arizona Project.

An acre-foot of water can cover one acre of land with one foot of water, or 325,851 gallons. The EPA says the average person uses 88 gallons of water a day at home, which equates to 32,120 gallons a year.

Related story

H20 & the I-10: Top Takeaways from the 10X Water Summit

Arizona’s reduced supply in Tier Zero will affect certain users of the Central Arizona Project canal system. There will be a slight reduction to some Pinal County farmers, and the pool of so-called “excess water” will be eliminated.

Regular buyers of excess water have included the United States, the Arizona Water Banking Authority and the agency that replenishes groundwater in Central Arizona, which enables new home building.

The CAP is writing a new policy for excess water if and when it returns.

‘Somebody’s going to have to use less’: Colorado River managers grapple with drought

PAGE – Years into a record-breaking drought across the Southwest, officials of the seven states along the Colorado River finally forged an agreement in 2007 on how to deal with future water shortages. Then they quietly hoped that wet weather would return.

It didn’t.

Those states now are back at the negotiating table to hammer out new deals to avoid a slow-moving crisis on the river system that supports 40 million people from Colorado to California.

You can see the extent of the problem in a place like Page, Arizona, on the southern edge of Lake Powell, the second-largest reservoir in the country behind Lake Mead.

Jennifer Pitt, who works on Colorado River policy for the National Audubon Society, stands on an overlook peering down at the lake and the immense concrete dam holding it in place.

“Now you can tell that there’s a river here underneath this reservoir because it has somewhat of a linear shape,” said Pitt, tracing the red rock canyon with her finger. “And it’s wending its way towards where we’re standing, here, overlooking the Glen Canyon Dam.”

The canyon behind the dam is stained with a stark white ring. For the past 20 years, Pitt said, demands for water have outstripped the supply, meaning Lake Powell and Lake Mead, behind Hoover Dam further downstream, continue to drop. Both are less than half full.

Without changes to how the two reservoirs are managed, Pitt said, levels could dip below the point where no water can be released, referred to as “dead pool.”

“If that happened, that would be a catastrophe for this region’s economy,” she said, “for all of the people who depend on the Colorado River and for all of the wildlife that depends on it as well.”

(The National Audubon Society receives funds from the Walton Family Foundation, which also provides funding for KUNC’s Colorado River coverage.)

It’s not about blame

That dystopian future of abandoned farms, dried-up streams and water-stressed cities is one that James Eklund of the Upper Colorado River Commission and other water managers are attempting to avoid.

“Take Lake Mead. More is being taken out than comes into it,” Eklund said. “Like your bank account, if you do that over a sustained period, you will run a deficit, and if you’re talking about water for 40 million people and economies that are massive – fifth-largest economy in the world, the Colorado River Basin represents – then that’s significant.”

Managers are attempting to boost reservoir levels with a suite of agreements under the umbrella of “drought contingency planning.” The premise is simple: Cut water use now, use that saved water to bump up Powell and Mead, and doing so will help to avoid bigger problems in the future, when supplies are likely to be even tighter.

Calcium deposits on the rock formations at Lake Mead, the largest reservoir on the Colorado River, show the impact of lingering drought on water levels. Hydrologists fear the reservoir will drop to the level at which no water can be released – a situation known as “dead pool.” (File photo by Alexis Kuhbander/Cronkite News)

Water officials in Colorado, Utah, New Mexico and Wyoming are working on a plan that covers the river’s Upper Basin and focuses on boosting snowpack with weather modification, better management of reservoirs and creating a water bank in Lake Powell.

The Lower Basin plan, being worked on by officials in Arizona, California and Nevada, is meant to create new incentives for farmers and cities to conserve water in Lake Mead and to agree to earlier, deeper cuts to water use so the reservoir can avoid dropping to dead pool levels.

Tuesday, water officials with all of the states, except Arizona, released draft agreements that spell out water cuts to boost levels at Mead and Powell according to azcentral.com. Arizona water officials plan to work through November to develop an agreement that state lawmakers would need to approve next spring.

“There is clearly enough evidence that if we were to have another 2000 to 2004 kind of a multiyear drought, the system is in very serious trouble,” said Eric Kuhn, the former general manager of the Colorado River District in Glenwood Springs, Colorado.

When the current management guidelines were written in 2007, planners were optimistic, Kuhn said.

“Historically, we’ve always said, ‘Well, next year will be better,’” Kuhn said. “And that’s the easy way out.”

Now, after another of the driest and hottest water years on record, much of that optimism has evaporated.

Kuhn said Arizona has had the hardest time coming to an agreement because of intrastate battles over who will take cuts to water allocations and when they’ll take them. But states in the river’s Upper Basin have had issues, too.

One example is with the concept of demand management.

“It’s the difficult one,” Kuhn noted. “Somebody’s going to have to use less.”

Kuhn said there’s a fear that if those cuts aren’t doled out fairly, it could injure economies throughout the Southwest. Colorado River District officials and agricultural interests from Colorado’s Western Slope have said they’re on board with a demand management program only if farmers are given a choice about how much water they give up, and that they’re paid for forgoing water deliveries to their operations. But state officials have left the door open to mandatory cutbacks in a crisis.

Lake Mead sports a white “bathtub ring” more than 100 feet tall in this December 2015 photo, illustrating how far the water level has fallen after years of drought. (File photo by Alex Demas/Cronkite News)

Over the past three years, drought contingency negotiations have laid bare old tensions throughout the basin. Farmers and cities have blamed each other’s collective water uses for decades. And the same is true with water managers protective of their own interests in either the Upper or Lower basins.

“The thing we have to remember is (water use) in the basin is over 80 percent agriculture,” said Colby Pellegrino, who handles Colorado River issues for the Southern Nevada Water Authority, the utility serving metro Las Vegas.

Current conservation programs, like the utility’s aggressive buyback of residential lawns, won’t be enough, Pellegrino said.

“We can take out all the lawns we want and still not solve the problems that climate change is going to throw at us,” Pellegrino said.

Climate change is just one pressure to get these deals done quickly. The U.S. Department of the Interior has given the Colorado Basin states an end-of-year deadline to get things done. If not, the assumption is the feds will step in to do it for them.

“That’s I think a fear of everybody on the river, especially in the Upper Basin,” said Jennifer Gimbel, a former Interior undersecretary, now with Colorado State University. “And the last thing we want is interference by the federal government in that role.”

The fate of the entire region hangs in the balance, said Gimbel.

At Glen Canyon Dam, Pitt, with the Audubon Society, said more than the fates of people and economies are tied up in river politics: An entire ecosystem is at stake.

“I think a lot of people who care about wildlife in this region are concerned,” Pitt said. “And it’s not just birds. Seventy percent of all wildlife in the arid West rely on rivers at some point in their life cycle. So it has outsize importance for anyone who appreciates nature in this part of the country.”



This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.