From Wichita to Windhoek, municipalities and water utilities are focused on three crucial strategies: recharging, recycling, and reverse osmosis.
By Tim Heffernan
(Illustration: Chad Hagen)
The humanpopulation is increasing rapidly, putting intense pressure on our most fundamental natural resource: fresh water. The developing world is growing fastest, making the challenge of supplying water especially acute there. But the population of the United States, unusual among industrialized nations, is also growing rapidly — at 0.7 percent a year, more than twice as fast as the European Union. And as the ongoing drought in California shows, not even the richest nation on Earth is immune to water crises.
Every new “mouth to feed” is also a new thirst to slake. But the challenge is not just demographic. As it grows more populous, the world is also becoming wealthier and more industrialized. Industry is immensely thirsty in its own right; nearly one-quarter of China’s fresh water, for example, goes to its factories — compared to just 12 percent to homes. And wealthier people rapidly adopt modern technologies, like refrigeration and telecommunication, that in turn depend on the thirstiest technology of all: electricity. Coal, oil, gas, and nuclear power plants produce electricity by turning vast quantities of fresh water into steam. (In 2010, power generation accounted for 45 percent of all water usage in the U.S. — four times the entire municipal usage, and nearly 50 percent more than all the water used to irrigate America’s farmland. The vast majority of all water withdrawals are fresh water.)
Measures to conserve water are being adopted everywhere, and in endless variety, from low-flow toilets to credit markets for water savings. Some of the most innovative — but least heralded — work is being done by water utilities themselves. Here, we highlight five case studies that together illustrate some broad global trends in confronting the crisis.
1. Recharge Aquifers by Putting Back as Much as You Need to Take Out
People have been using groundwater for drinking and irrigation for millennia. But industrialized agriculture upset the ancient balance whereby rain and snow replenished groundwater. Today, extensive pumping has lowered water tables by tens and even hundreds of feet. That not only makes water costlier; it can also encourage infiltration by industrial and agricultural chemicals. One of the most ambitious efforts to correct for this is in Wichita, Kansas. During periods of high flow (as during the spring thaw), water is pumped from the Little Arkansas River, decontaminated, and injected into the city’s aquifer. When the project reaches full capacity, up to 100 million gallons of water per day will be recharged this way. The pilot phase of the project saw water levels rise by 10 feet — despite record pumping.
—Hansen, C.V., Whisnant, J.A., and Lanning-Rush, J.L., “Status of Groundwater Levels and Storage Volume in the Equus Beds Aquifer Near Wichita, Kansas, 2012 to 2014,” United States Geological Survey, 2014.
This story first appeared in the May/June 2016 issue of Pacific Standard.
2. Recognize That Recharging Is Not Just for Farmland Anymore
Stanford University’s Water in the West program has found that aquifer recharging, at a median cost of $390 per acre-foot, is not only far more economical than the traditional method of mass water storage — dams and reservoirs — but that the capacity of California’s natural aquifers is 17 to 26 times greater than that of its artificial stores. Little wonder, then, that the City of Los Angeles is currently pursuing several di erent recharge projects simultaneously. The L.A. Department of Water and Power’s Stormwater Capture Master Plan will (when finally completed) lay out a comprehensive strategy for returning precipitation to the city’s aquifer, rather than channeling it directly into the Pacific, as has been done for a century. The methods will largely be passive: using parks, cisterns, permeable road materials, and “spreading grounds” to allow rainwater to soak into the soil.
—Choy, J., McGhee, G., and Rohde, M., “Recharge: Groundwater’s Second Act,” Water in the West (Stanford University), 2014.
3. Figure Out the Best Ways to Provide Wastewater Treatment
The water from our taps eventually goes down our drains — along with other, less salutary stuff. Wastewater treatment is nothing new, but until recently the basic motivation was environmental: Sewage was brought to acceptable standards for discharge into the wild, but wasn’t seen as having economic or social utility. That’s changing. Treated liquid sewage is increasingly used for agriculture and aquifer-recharge. And solid waste is increasingly used as a source of biogas, a “green” fuel whose combustion can provide some or all of the energy used to recycle sewage into useful products. Mexico’s Agua Prieta wastewater treatment plant is a standout example. It processes as much as 1.3 million cubic meters of sewage each day. Efficient production of biogas makes it 100 percent self-sufficient, and, by eliminating its reliance on fossil-fuel energy, reduces its carbon footprint by 40,000 tons per year.
—Rhoda, R., and Burton, T., “Recent Progress in Waste Water Treatment in Mexico,” Geo-Mexico, 2014.
4. Get Over the “Ick Factor” of the “Toilet-to-Tab” Movement
It’s been possible for decades to recycle human and animal waste into perfectly potable water. But the ick factor has made doing so politically impossible, at least in the U.S. That may be set to change, thanks to numerous examples set in the developing world, where squeamishness is often an unaffordable luxury. The Ujams Industrial Water Reclamation Plant in Windhoek, Namibia, takes the discharge from (among other things) a slaughterhouse and a tannery and recycles it into more than 5,000 cubic meters of water clean enough for agriculture each day — a valuable commodity in its own right in sub-Saharan Africa’s driest country. San Francisco Bay Area residents may be especially interested: The Silicon Valley Advanced Water Purification Center, which began operating in 2014, currently brings eight million gallons of treated wastewater each day to ultra-clean, potable standards.
—“Silicon Valley Advanced Water Purification Center,” Santa Clara Valley Water District, 2015.
5. Always Pursue New Sources, Because You’re Going to Need Them
Here’s the cruel fact of seawater: effectively limitless, it is also essentially useless for most human needs. Every Boy and Girl Scout learns, of course, that by evaporating and condensing cupfuls of seawater, life-giving fresh water can be created. But advances in another process, called reverse osmosis, have made desalination more energy- and cost-efficient. In the past five years alone, huge reverse osmosis desalination plants have opened from Tunisia to Trinidad; dozens more are under construction, including in the U.S. But a small desalination facility that opened last year in tiny Cambria, California, has generated the most excitement. Housed in a couple of shipping containers and designed, built, and installed in under a year using off-the-shelf parts, it offers the promise of relatively affordable, scalable fresh water — not just to well-off Californians, but to the world.
—Schneider, K., “California Drought Puts Desalination, Fresh Water From the Sea, in a New Light,” Circle of Blue, 2015.