Recycled wastewater has been used for decades to irrigate crops, golf courses and landscapes. Now, with water scarcity affecting growing areas globally, more communities are looking to turn treated sewage into potable water — and this creates a huge opportunity for companies including Dow Chemical that provide toilet-to-tap technology.
“Communities and companies are increasingly realizing the economic value of clean water — and that’s driving growth in Dow’s water business at two times [the rate of] the global GDP,” Dow chairman and CEO Andrew Liveris tells Bloomberg News.
In 2007, Orange County, Calif. opened the world’s largest sewage purification system to increase drinking water supplies. It currently produces 100 million gallons of potable water per day, the Orange County Register reports.
El Paso, Texas also treats its wastewater to produce potable water. There, as in Orange County, the treated wastewater is sent through an aquifer before being pumped and receiving additional cleaning.
Direct Potable Reuse
Other Texas cities are moving forward with toilet-to-tap technology as the drought continues to shrink water supplies.
Operating under a stage 5 drought, Wichita Falls, Texas, last year began recycling millions of gallons of wastewater. Unlike El Paso, Wichita Falls uses direct potable-reuse technology — that is, the treated wastewater will not be sent through an aquifer before use — as does a plant in Big Springs, Texas, which, in 2013 became the first project of its kind in the US to use direct potable reuse.
Extreme drought conditions in California are now forcing the golden state to follow Texas’ lead. Last year California Gov. Jerry Brown signed a bill that requires state health and water officials to report by September 2016 on the feasibility of developing uniform standards for recycling wastewater for direct potable reuse.
“Toilet-to-tap or direct potable reuse is the future of potable water wherever water shortages are acute,” says Lux Research analyst Abhirabh Basu. “It is also more likely to find traction in regions where there is a combination of water shortages and limited agriculture, like Los Angeles.”
Last month the Metropolitan Water District of Southern California approved $15 million for a wastewater recycling demonstration plant. The toilet-to-tap program would serve Los Angeles County, Orange County and potentially San Bernardino County, water district COO Debra Man told NBC News.
While the facility would initially use the recycled water to recharge groundwater basins, “down the road,” it could move to direct potable reuse, the water district says.
California’s drought-stricken communities are preparing for indirect potable reuse — but treating the wastewater and pumping it into an aquifer before reusing it is a less efficient recycling method, Basu says. “As drought conditions worsen in western US and elsewhere in the world, we expect more municipalities to encourage direct potable reuse.”
The ‘Ick’ Factor
There is a major hurdle to toilet-to-tap, however, and it has nothing to do with the technology involved. It’s the “ick factor:” convincing the public that it’s safe — and doesn’t taste gross — to drink treated sewage.
As Paul Rozin, a social psychologist at the University of Pennsylvania who’s researched consumer response to toilet-to-tap programs, tells Bloomberg News: “Accepting recycled wastewater is kind of like being asked to wear Hitler’s sweater. No matter how many times you clean the sweater, you just can’t take the Hitler out of it.”
But, says Basu, in places with limited access to freshwater like Singapore and extreme drought like Texas, the ick factor isn’t a problem.
“Singapore’s NEWater plant treats wastewater to drinking water standards and meets about 30 percent of the country’s water demand,” Basu says. “The best way to tackle the ick factor is to educate the public about the process and the advantage of reusing wastewater. In the long run this will prove to be a better strategy than relying on consumers to change their behavior, which has a limited effect and is more difficult to achieve.”