KNAU and Arizona News
Mon December 5, 2011
The Future of Reclaimed Wastewater
Tonight, the Flagstaff City Council will hold a panel discussion on the current and future uses of reclaimed wastewater. While the thought of drinking treated wastewater is stomach-churning to many, it may – someday – become standard in the U.S. And the conversation over what to do with wastewater is a heated one.
At a holiday tamale making workshop in Flagstaff, participants set about preparing their ingredients. They grate cheese, chop cilantro and soak chiles and corn husks in tap water. But, how would they feel if the water being used in their meal was treated wastewater.
“I’m not comfortable saying yeah, I’d drink wastewater…my understanding is they can’t filter out pharmaceuticals and that’s what freaks me out…that’s the direction we have to move because fresh water is not in abundance. ..7 billion people on the planet! We’re gonna have to use treated water.”
For decades many countries, including England, France and Australia h ave been using treated wastewater as drinking water. And even here, some U.S. cities in Texas and California have proposed similar plans. It’s hardly anyone’s first choice, but it may just come to that.
“You know, that’s the boat that the whole nation is in and the whole world is in for that matter.”
Chuck Graf is a hydrologist with the Arizona department of Environmental Quality. He says the state is already using reclaimed wastewater for a number of things, including agriculture, irrigation of parks and athletic fields and power plant cooling. But it’s also being recharged into aquifers across the state, which means it could co-mingle with drinking water supplies at some point.
“You only have a few options of where water from a wastewater treatment plant can go. It doesn’t just evaporate and go away.”
Graf says most of Arizona’s wastewater treatment plants can remove up to 99 percent of known chemical and biological contaminants currently regulated by the Environmental Protection Agency. And nature’s underground filtration process removes some too. But, with thousands of pharmaceutical drugs, personal care and household products going down the drain, it’s impossible to know if everything that should be filtered out is being filtered out.
“There’s multiple compounds and every compound has its own chemistry. So getting rid of all of them is a really big trick.”
Cathy Propper is a biology professor at Northern Arizona University. She studies how the chemical compounds known as “endocrine disruptors” in treated wastewater affect developmental behavior and reproduction in certain aquatic species.
“The thing with endocrine disruptors, as they’re called “emerging contaminants”, a lot of them have no regulatory oversight over them for wastewater. Wastewater’s regulated for a lot of biological contamination and for color and turbidity, but it’s not regulated for these emerging contaminants yet, so the regulation really hasn’t completely caught up to the science.”
Propper says some published studies show reproductive mutations in certain aquatic species living in effluent discharged from wastewater treatment plants. And scientists are beginning to look at how exposure to treated wastewater could affect humans. Brad Hill is the director of utilities in Flagstaff.
“Nationally, there’s a lot of eyeballs on this and a lot of money being funneled into how we treat, or can we treat, for these compounds of concern.”
Hill says that is the lingering question. It remains unclear whether natural underground filtration works any better or faster than filtration done at a wastewater plant. This becomes especially important as demand for drinking water outweighs supply.
“We project that as the community grows, reclaimed water is the only source of water that grows along with the community. So the question becomes, what does the community want to do with it, how do you want to treat it and how do you want to use it.”
Tonight, the Flagstaff City Council will hold a panel discussion on the current uses and research regarding treated wastewater. It starts at 6:30 at NAU’s DuBois Center and is open to the public.