The golden state's historic drought is forcing residents to reconsider the "yuck factor" of wastewater re-use.
The golden state’s historic drought is forcing once-squeamish Californians to take a new look at “toilet-to-tap” water re-use. Or as they prefer to call it in Fountain Valley, “showers to flowers.” The town in conservative Orange County is home to the largest water recycling plant in the world, and an example during this epic drought of the life-altering changes California will have to make to avoid running out of water. First, residents will need to get over the idea that water is an infinite resource. Or that it pours out of the tap straight from a pristine, underground spring.
This is the third year of drought in the West. By July's end, more than half of California had fallen into the worst category of “exceptional drought.” The state has made it illegal to hose down a sidewalk or operate a fountain, punishable by a $500 fine. But those measures are largely symbolic, and the state is going to have to do much more to guarantee California a long-term supply of water.
“Our sources of supply are literally drying up,” said Michael Markus, general manager of the Orange County water district, on a tour of the water plant. The state’s main sources of water—snow melt from the Sierra Nevada, imported water from the Colorado river, and groundwater—are all in decline.
So why not re-use water? Orange County has been doing it for six years, using highly purified waste water to replenish groundwater reserves.
“We consider waste water not a waste but a resource,” Markus said. “If we didn’t have this water, we wouldn’t be able to pump as much out of the basin,” he went on. “The basin would go into a state of overdraft.”
The water re-use plant currently produces 70 million gallons a day, turning residential waste water—from dishwashers, showers, washing machines and toilets—into potable water.
In February 2015, that amount will rise to 100 million gallons a day, as a $140 million expansion comes online. That will be enough to supply 850,000 people, or about one-third of the 2.4 million residents of Orange County.
Markus said the cost is significantly lower than importing water from northern California, and about half the cost of desalinating sea water—and the supply is guaranteed.
The water goes through three stages of purification: filtration through a series of tiny straws to remove bacteria, reverse osmosis to remove dissolved chemicals, and exposure to UV light with hydrogen peroxide. By the time it leaves the plant, it is distilled water.
About half of the water is pumped into injection wells to serve as a barrier against seawater intrusion. The rest is pumped 13 miles to underground basins in Anaheim, where it filters through layers of sand and gravel, gradually becoming part of Orange County’s water supply.
But it could still take some time before Californians get over their aversion to the idea of water re-use—or adjust to the notion that they can’t afford to go on dumping waste water. The state currently dumps some 1.3 billion gallons of water a day into the ocean off the coast of southern California.
One of the state's first attempts to popularize water recycling, in San Diego in the 1990s, collapsed because of what water managers call the" yuck factor." Those attitudes are changing because of the threats to the state's existing water supply. California’s department of water resources reported last April that groundwater reserves had dropped 50 feet below historical lows across much of the state.
California law still does not allow the direct re-use of the water leaving the Orange County plant—even though it is purified to a higher standard than groundwater supplies. But the state regulator is looking to draft new rules to allow direct re-use of water by 2016.
“I think this plant is very important to protecting the strategic reserves of water," said David Feldman, who teaches water management at the University of California at Irvine. "If we did not have this groundwater basin, we would have to import virtually all of our water.”
He said he expected to see growing water re-use in California and across the West—although not necessarily for potable water. Other water agencies in California are now actively looking at how to make best use of treated wastewater, storm water, and agricultural runoff, according to a research project from Stanford University.
Los Angeles and San Diego are actively pursuing their own water re-use facilities. Riverside, on the Santa Ana river, also operates a water recycling plant that produces water for irrigation. Some 78 water projects have been funded so far, all aimed at putting water back into underground aquifers, Water in the West researchers found.
Those projects were on the drawing board before the drought—but they could help California get through the next one.