Parched

As climate change marches on, the need for clean, safe water leads us to tougher challenges, bigger questions, and better answers
By:
Eric Van Meter, Jacob Chinn photos

Water is one of the simplest molecules: two humble hydrogen atoms (the most common in the universe) bonded to one workaday oxygen atom (itself the third-most abundant of the elements). 

For such a modest molecule, it’s indispensable. We can go just days without drinking some, though we can go without food for weeks. It’s essential to our electricity, fabrics, plastics, and fuels. And that coffee you had this morning? It took nearly 40 gallons of water to bring you one cup. In fact, the American lifestyle uses more than 2,000 gallons of water a day per person.

We know water covers most of the planet, but only a tiny fraction of its H2O — less than one-tenth of one percent — is available to not just humans but every last plant and animal. Some is groundwater that hasn’t made its way into aquifers and much is frozen in polar ice caps. But the vast majority of our water is just too salty. 

Salt of the Earth

In Arizona’s Navajo Nation, it’s not uncommon for scrubland to stretch for miles between one or two homes tucked far from running water. Families truck in water, a steep cost in communities where nearly 40 percent of the people live in poverty — the highest incidence in the U.S. — but they have no choice. The water in the land is salted.

Brackish groundwater isn’t uncommon in arid regions, but until recently, the U.S. had seen it as a supply not worth tapping. Today, with Western states experiencing less and less rainfall, governments are giving it more and more thought. Researchers estimate that Arizona alone holds about 20 trillion gallons of treatable brackish water less than 1,200 feet below ground. 

Desalination provides the U.S. with less than one percent of its potable water. The problem lies not in how to separate salt and water but in how much power that process requires. On the other hand, consider that tribal reservations (of which the Navajo Nation is the largest) have, according to some estimates, the solar power potential to supply the entire country’s electricity needs four times over.

If you’re thinking those facts add up to possibility, you’re not alone. “We believe it’s possible to take the almost brackish water that underlies these sparsely settled areas, pump it to the surface, and remove enough salt to bring it to drinking water standards without access to the power grid,” explains Robert Arnold, a professor in the UA Department of Chemical and Environmental Engineering who is affiliated with the UA’s Water Resources Research Center in the College of Agriculture and Life Sciences. 

He is part of a team of UA researchers piloting a project that joins the UA and solar energy partner Cogenra with funding from the U.S. Bureau of Reclamation in a distillation solution that’s elegant and effective: Solar panels collect thermal energy. Some of that energy is converted to electricity to pump water out of the ground and circulate it through the system, Arnold explains, while the rest remains thermal, used to heat and evaporate the water. The vapor then passes through a membrane, leaving its salt behind. 

Waste Not, Want Not

While desalinated water could offer major new resources for some of the Southwest, the true bounty may be even closer: the water we drain and flush away each day. The idea isn’t new. Pima County began using wastewater for irrigation as early as the 1960s, says Ian Pepper, a UA professor in the Department of Soil, Water and Environmental Science and director of the Water and Environmental Technology center and the Environmental Research Laboratory. Pima County was something of a pioneer then, and now it’s joining forces with the UA to reclaim the title.

“Our goal is to become the premier center of this type anywhere in the world,” Pepper says, referring to the new, 22,000-square-foot, LEED-certified facility that will house the Water and Energy Sustainable Technology (WEST) initiative, a groundbreaking partnership between the UA and the Pima County Regional Wastewater Reclamation Department. 

Pepper co-directs WEST with Shane Snyder, a professor in the UA Department of Chemical and Environmental Engineering. Together they bring a rare combined expertise in contaminants, chemical and microbial, and under their leadership the UA will become the only university on the planet directly linked into a water utility. That link will give Snyder, Pepper, and others the ability to do flow-through experiments at a scale no lab tanks can match.

Excitement around WEST is flooding the research community. NASA has expressed interest in how the UA might help advance a nanotech platform for detecting pathogens on crops as well as converting urine to potable water in outer space. The potential is for a world premier water-treatment R&D initiative — one that will provide student education and public outreach that together will fundamentally shift the way we use and think about effluent water.

“People have been recycling water for a very long time,” Snyder says, referencing the Goreangab Water Reclamation Plant in Namibia, which began the world’s first wastewater treatment for direct reuse and has operated for more than 30 years without a single case of illness. “We can recycle wastewater back into drinking water with far less energy than it takes to import water. For Pima County, it will be far less expensive to purify our wastewater than to try and import more. It’s a matter of necessity and economics.”

The Ins and Outs of Water

As tricky as it may be to rid water of contaminants, the economics of water are even trickier, a point made by Shane Burgess, vice provost and dean of the College of Agriculture and Life Sciences. “We produce the best quality alfalfa in Arizona for the least amount of water,” he says. That alfalfa is fed to cows, which produce milk, which becomes high-value products that contribute to Arizona’s agricultural economy.

Dairy farms in Arizona produce more milk per cow than farms in all but two other states. That efficiency led Ehrmann and Franklin Foods to begin making Greek yogurt and cream cheese in Arizona last year, joining Daisy, Abbott Nutrition, Shamrock Foods, and others.

Burgess’ point is this: Arizona farmers turn water into specialty goods exported to nearby states at a carbon footprint dwarfed by sourcing the same products from Wisconsin. And while some may grouse that agriculture draws 70 to 80 percent of Arizona’s water and exports much of it as food, the industry also contributes a vital $16 billion to Arizona’s economy. “We are the salad bowl for all of the U.S. for three months of the year,” Burgess notes. “We produce grass-fed beef, quality wine, and we even have aquaculture in shrimp, tilapia, and bream.” In fact, Yuma is the winter vegetable capital of the world, growing 90 percent of all leafy vegetables in the U.S. from November through March.

That big picture view is critical when looking at history as well, Burgess says. “Moving from hunter-gatherers to farmers was fundamental to the development of human cultures,” he points out, adding that challenges have been a constant in how we get and use water. “We’re at another iterative stage of those challenges, but there are solutions. We need to decide our best uses of water. We need to price it appropriately. We need to invest in new technologies and create an economy that drives us to do the right things. This is why we have universities, to be able to make these iterative steps when we need them.”

New Models for a New World

Universities play a crucial role in discovering solutions, and they also educate each generation about how to shape the future. Dean Joaquin Ruiz at the UA College of Science is energized by another way the UA is facing water challenges, working in partnership with educators and researchers in Mexico to develop a new educational response to climate change. Ruiz also is a professor in the UA Department of Geosciences, vice president for innovation and strategy, and executive dean of the Colleges of Letters, Arts and Science.

“The most exciting thing to me is that we really are trying to create a new curriculum so that students can study adaptation and the impact of global climate change in a more holistic way,” Ruiz explains. “Right now, when you talk to people who are studying the consequences of global climate change, you may be talking to a geologist or a hydrologist. But I think the kind of science that we need to really address these issues falls in between all these established disciplines. We are creating the curriculum for that science.”

As Ruiz and his colleagues evolve this new model, they have the benefit of Biosphere 2, the landmark science facility owned by the UA since 2011. Its new Landscape Evolution Observatory (LEO) offers the advantage, like the WEST initiative, of experimentation at otherwise unprecedented scale and unmanageable complexity.

“As global climate change progresses,” Ruiz says, “it is not only going to get hotter in places like the Southwest, but the pattern of rain is also going to change. When the pattern of rain changes, our vegetation is going to change. As our plants change, then the amount of evapotranspiration — the humidity in the atmosphere — is also going to change, and that drives weather patterns as well. That whole system, which is so complex, we are trying to understand through these studies at Biosphere 2.”

That understanding is already growing as scientists at LEO manipulate rainfall on a constructed mountain slope to study how it shifts erosion and moves through soil. “We can measure water flow, we can measure humidity, we can measure CO2 — we can measure a million things,” says Ruiz. “So we are basically studying every change in this system from fundamental hydrology to evapotranspiration to soil creation.”

Time for Change

While we’re just starting to plumb secrets at LEO, UA scholars have been managing water issues through direct observations for years. “Drought plays an important role for ranching in this state, and we’ve spent a lot of time working with the ranching community on best practices,” says Stuart Marsh, director and a professor in the UA School of Natural Resources and the Environment. He also is a professor in the School of Earth and Environmental Sciences and is affiliated with the UA’s Water Resources Research Center. Working with agencies like the Bureau of Land Management, the UA has long helped ranchers make better decisions about when and where to move their herds, he explains, and technologies like satellite imaging have provided new tools for tracking the effects of drought over large areas in real time. 

Satellite images, solar-powered desalination, even the potential of the WEST initiative — all hold promise, but are they enough? “Technology will make things feasible but costs will keep increasing, and we’ll still need to use less water,” says Jonathan Overpeck, a Thomas R. Brown Distinguished Professor and Arizona Regents’ Professor in the UA Departments of Geosciences and Atmospheric Sciences and co-director of the Institute of the Environment.

“There are many things that could make our water go farther and augment our supply, but they’re all costly. Often a big part of that cost is energy that’s produced with fossil fuels, which accelerates climate change and makes the problem worse. So perhaps the best solution would be to stop climate change.”

The Third National Climate Assessment, issued in May, warns of fiercer fires, deadlier droughts, and more savage storms. Here, Overpeck says, is where we can do the most for our water security. 

“We have in hand the technologies to stop climate change if we choose,” Overpeck says. “That switches the question away from technology to one of political will. But there is a lot of vested interest in preventing that political will from developing, and solutions aren’t being implemented nearly as widely as they could be.”

The power to change that can only come from a combination of groundswell support and top-down legislation, Overpeck says.

“We need to all work together to overcome those special interests that want to keep making money from wasting water, wasting energy, and producing CO2,” he says. “We have to overwhelm them. The answers are there — we just need everyone to realize that they can have their cake and eat it too.” 

Overpeck notes that as the biggest and most comprehensive “water campus” in the world, the UA is discovering and discussing solutions with international application, especially for the arid and semi-arid regions that make up about 40 percent of Earth’s landmass. Those applications will improve quality of life on a global scale while creating more opportunities for the UA to commercialize and monetize its innovations. 

Overpeck’s optimism converges with that expressed by Dean Burgess just days before: “We can be both more sustainable and more competitive. It doesn’t have to be a choice.”