Amid ongoing drought, cities look to make wastewater more usable
As the combined effects of a historic drought, increasing population and a changing climate continue to roil the Southwest and its water supply, metro Phoenix cities look for ways to make every drop count.
Peoria recently approved a $2.2 million project to recover its wastewater — everything that goes down your drain — and inject it on a more mass scale into the ground, where the city pulls its drinking water.
Wastewater for decades has been an important renewable resource for Arizona cities, especially those in the West Valley that don’t receive as much Colorado River water as Phoenix and its neighbors to the east.
The wastewater is typically treated and used for a number of things: irrigating non-food crops, watering city ballparks and replenishing the underground wells, or aquifers, that store
drinking water.
New state rules let cities apply to send treated wastewater straight to home taps, but no Arizona city has applied yet.
For now, cities use a more roundabout approach than what they’d consider “toilet to tap,” even though traces of the water you flush, after replenishing aquifers, might eventually come to your kitchen sink.
“We don’t have what we call direct toilet-to-tap,” said Karen Smith, former Arizona Department of Water Resources deputy director. “Yet.”
The Peoria City Council unanimously approved the new water-treatment facility in October. It will treat wastewater and inject about 1 million gallons each day back into the ground.
The city will also continue to rely on a facility in New River, north of Phoenix. But the new facility will let Peoria store more of the treated wastewater underground.
“We actually put more water into the ground, overall, in our system than we pump out,” said Cape Powers, Peoria’s planning operations manager.
After the city pumps the treated wastewater into the ground, it eventually will withdraw and treat the groundwater that is mostly used for drinking. But it’s used elsewhere, too.
The fields in the Peoria Sports Complex where the Seattle Mariners and San Diego Padres play, the park around City Hall and some homeowners associations all use the treated wastewater to water grass, Powers said.
While the Valley doesn’t get its drinking water straight from the drain, it’s not far off.
In Arizona, treated wastewater can end up as part of the drinking-water supply, but it won’t go straight from the drain to the tap.
“We do have treated wastewater as part of our drinking water,” Smith said. “It’s called indirect reuse.”
Even if the water swirling down your toilet bowl gets treated and mixes with your future drinking water, there’s a reason most cities don’t take it straight from the toilet to the tap.
“Frankly, it alleviates some of the yuck factor,” Smith said.
Before Valley cities starting treating waste, Arizona’s Natural Wonder of the World made it popular.
Around the turn of the 20th century, Grand Canyon National Park started treating wastewater because it didn’t have other reliable sources of water, Smith said.
It didn’t truly become standard practice for the Valley until the Groundwater Management Act of the 1980s passed, she said.
Since then, the area has become a leader in wastewater treatment.
Officials believe Prescott was the first Arizona city to reuse 100 percent of its wastewater.
“We retain and are managing every drop of that,” said Craig Dotseth, Prescott public works director.
Scottsdale in October celebrated the 20th anniversary of its Scottsdale Water Campus, where it treats wastewater to drinking-level standards.
“We weren’t going to put anything into the aquifer unless we could prove it was an equal or better quality than what we were taking out of it,” said Nicole Sherbert, Scottsdale’s water spokeswoman. “We don’t have any chance whatsoever of degrading the aquifer.”
Although Scottsdale treats its waste to drinkinglevel standards, it’s used to water golf courses or pumped into the aquifer. Sherbert said the city is not considering sending that water straight to anyone’s tap.
As of January, cities in Arizona can apply for a permit that would allow direct reuse of wastewater — what’s called “toilet to tap.” But no one has, according to an Arizona Department of Environmental Quality spokeswoman.
“Potentially someone could apply for that, but nobody (in Arizona) really has that technology yet,” spokeswoman Erin Jordan said. “We wanted to have very strict rules in place to ensure safety.”
Texas and California already allow that to some extent, according to the Arizona Municipal Water Users Association.
That technology may not be as useful for the metro-Phoenix area as it is for smaller rural communities.
Warren Tenney, executive director of the water users association, said it’s important for the state to consider all the tools in its belt when it comes to water, even if it doesn’t need to use them all.
“We feel it’s important to have this resource available,” he said. “I see it more as something that a smaller community in rural Arizona would utilize much sooner than here in the metropolitan area.”