From flush to faucet: More places look to turn sewage into tap water

Photo: Wastewater is forced through microscopic holes in tightly wrapped membranes wound in these fiberglass vessels during the reverse osmosis stage of purification at Orange County’s Groundwater Replenishment System. Other communities around the state and country may soon emulate the Southern California county’s practice of recycling all of its wastewater. Matt Vasilogambros/Stateline

After an Orange County resident flushes her toilet, the water flows through the Southern California community’s sewer system, meanders its way to the sanitation plant, has its solids removed, is piped to a wastewater recycling facility next door and undergoes three different purification processes until it is clean enough to drink.

“It tastes like water,” said Mehul Patel, executive director of operations for the Orange County Water District’s project, after taking a gulp from a clear plastic cup at the sampling station, as he stood outside the final purification process facility on a warm afternoon earlier this month.

“It’s just like any other water, but it’s gone through a lot,” he said. “People shouldn’t judge where it came from, but where it is now.”

No large community in the U.S., not even Orange County, is taking water from toilets and transforming it directly into clean drinking water right now. But Patel’s demonstration might offer a glimpse of the future, as states and communities across the country design new plants that will do just that, giving communities more control over their water supply as the climate gets drier.

The idea is still new in many parts of the country. And officials face some pushback from skeptics concerned about the high costs of advanced purification systems and from a public not used to the idea of drinking what was once their own waste.

Every day, Orange County’s Groundwater Replenishment System, known to the locals as GWRS, purifies 130 million gallons of wastewater coming from 2.5 million residents. It’s the world’s largest wastewater recycling plant, and the first in the United States to recycle every ounce of its county’s wastewater. This system of pipes, purifiers and chemical reactions has become a required visit for any water official looking to adopt a similar program in another state.

Patel expects more visitors now that California’s top water officials are slated to greenlight new rules later this month that would allow counties to purify their wastewater and inject it immediately into the drinking water supply. If approved, as expected, regulations would go into effect in July.

Currently, all of Orange County’s recycled wastewater is used to replenish its groundwater aquifer and protect it from seawater intrusion. The water is later pumped out and purified once again to drinking water standards and distributed throughout the county. There are no plans to change this two-part process anytime soon.

Some Golden State communities do the same; others use their recycled wastewater to irrigate fields, water parks or merely dump it into the Pacific Ocean.

But as the state faces a drier future in which the amount of water coming from the Colorado River and the Sierra Nevada Mountains may not be reliable, top water officials say the state needs more sources of drinking water.

“We spend a lot of money and energy moving water from different parts of the state to Southern California, where it’s used once and dumped in the ocean,” said Darrin Polhemus, deputy director of the California State Water Resources Control Board. “That’s maybe not the smartest way to deal with a resiliency question.”

Communities across the country, even beyond the increasingly arid West, have been using recycled wastewater to shore up water supplies drained by larger populations, over-pumped groundwater aquifers, hotter summers and less precipitation.

Facilities are pumping out millions of gallons of recycled wastewater in Arizona, Georgia, Texas and Virginia. Regulators in Colorado, Florida, Iowa and Kansas are considering how to use it. In Arizona, for example, some cities use recycled wastewater to replenish dormant rivers and brew beer; others use it to refill underground aquifers, cool factories or keep parks and golf courses green. But rarely has wastewater gone directly into the drinking water supply.

Daniel McCurry, an assistant professor of civil and environmental engineering at the University of Southern California, expects that in two decades at least half of states will adopt wastewater recycling to meet the hydrological demands of a hotter, drier climate.

“Places you wouldn’t normally think of as dry or water-stressed at all are starting to build these plants,” he said. “And that’s only going to accelerate.

“Anywhere that’s primarily reliant on groundwater is going to have water reuse in their future.”