Arizona plans to allow treated wastewater for drinking, seeks public comments

Arizonans eventually will be drinking treated sewage, for the simple reason there isn’t enough water to serve a growing population.

The work on this is well on its way. In fact, the state Department of Environmental Quality is accepting comments for the next 30 days on the plans and standards it’s crafting for this “toilet-to-tap” water — what it prefers to call “advanced water purification.”

If all goes according to schedule, municipal and private water companies will be able to add the treated effluent to their supplies by the end of 2024.

To see the proposal and how to comment, visit azdeq.gov/awp-resources.

It’s not a question of “if’’ but of “when,” said Robin Silver, co-founder of the Tucson-based Center for Biological Diversity.

“The use of reclaimed effluent is inevitable in the arid Southwest, period,’’ he said. “That’s not really debatable anymore.’’

More to the point, it’s already happening.

Treated effluent now is discharged onto, and in some cases injected into, the ground. Eventually, it is pumped out after there has been a natural filtering process of sorts.

The next step is to convince people it’s OK to bypass that natural recharge and go directly from sewage treatment plant back to homes, albeit with additional processing, state regulators say.

“Essentially, all this technology does is take out that environmental storage in the ground and runs this water through advanced treatment processes that actually are much more efficient at removing contaminants, pollutants, than storing in the ground is,’’ said Randy Matas, a deputy DEQ director.

“There’s no new water,’’ Matas said. “It’s all recycled water.’’

Safe for users, Hobbs says

Gov. Katie Hobbs says the rules being developed by DEQ will provide for safe water.

“I am comfortable with science and technology ensuring that what we put into our water system is safe for users,’’ she said.

Asked if she will drink recycled water from the faucets in her home, the governor responded, “Yes.”

And a DEQ survey conducted earlier found 70% of residents polled said they will be somewhat or very likely to drink recycled water.

Convincing all Arizonans to accept the technology, however, will require proof that they can see, said Matas.

Scottsdale already started down that road through a demonstration project with several local breweries making beer with water they got from the city’s advanced water treatment facilities. In Scottsdale’s case, that includes not just normal purification to A+ levels — good enough to discharge into streams and for irrigation — but also other processes including reverse osmosis, membrane ultrafiltration and treatment by ultraviolet light.

The rules being written for the state won’t specify exactly what methods each community needs to incorporate, Matas said.

“What we’re proposing in our rule is actually establishing the treatment standards and leaving it up to the utilities to assemble the specific treatment technologies and the specific order to treat to the standards,’’ he said. That will be based on the quality of the water they are starting with.

“It gives utilities and also water treatment industries the space to innovate, develop new technologies, bring those new technologies online that may increase efficiency and decrease costs as they become available,’’ Matas said.

Questions to be answered

Silver said issues remain, though.

One involves “compounds of emerging concern,’’ including antibiotic-resistant genetic material that is getting through the wastewater treatment process. That arose in Flagstaff a decade ago when research found genetic indicators of what could be antibiotic-resistant bacteria in both potable and reclaimed water.

Silver said these are not yet recognized as contaminants. “It’s going to need to be addressed.’’

But Matas said to the extent that’s a problem, it has nothing to do with whether Arizona should go ahead with advanced water purification.

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“All those things are in a discharge from a traditional wastewater plant to a surface water which is then removed and treated and put into drinking water,’’ through the normal process of filtration through the ground, he said. “All this is doing it taking out that environmental buffer.’’

Matas said the various advanced treatment processes take out other things that now show up in water that is pumped from underground. In Arizona, that specifically includes various metals in the soil.

“So you’re getting better and more complete treatment than what you would get in the natural environment,’’ he said.

Silver agreed this isn’t specifically a problem with direct use of treated effluent versus the current processes.

“No matter where they put it in, somebody’s going to use it,’’ he said.

Still, Silver said, if the state is going down the path of direct use of treated effluent — and promoting it — there are questions that need to be answered.

“We just need to assure ourselves that as we’re learning more and more about what’s in reclaimed effluent that we are removing hormonal elements, pharmacological elements and antibiotic-resistant genetic materials,’’ he said.

Also, said Matas, “When you change the chemistry in the water, of course you have to consider that as far as the distribution system and corrosion control. So these are things the utility will have to consider when they’re getting their permit for advanced water purification.’’

Affordability, acceptance

Then there’s the question of how much this will add to each monthly water bill.

“The cost for consumers will vary by the utility that’s putting it in place and the amount of treatment required and the size of their customer base,’’ Matas said.

The DEQ survey about whether people are willing to accept recycled water also found that 71% listed the price tag as a concern.

The department is trying to address that with suggestions some people could save money.

“Instead of relying solely on bottled water or expensive filtration systems, you can enjoy purified water at a fraction of the cost, primarily if your local water utility provides it,’’ DEQ is saying online in its list of questions and answers.

Is DEQ saying people will be able to stop buying bottled water and can turn off their filtration systems?

“Water treated through advanced water purification not only complies with and exceeds all water quality standards but offers a flavor profile akin to purified bottled water or home reserve osmosis systems,’’ said DEQ spokeswoman Alma Suarez. Still, she said “personal preferences and circumstances may vary.’’

“Some people may still choose to buy bottled water or use filtration systems for convenience or specific needs,’’ Suarez said.

Matas, for his part, prefers to see the issue in broader terms.

“The cost of Arizona running out of water which would stall development, that would stall the economy and lead to water scarcity would drastically increase cost of living for Arizonans,’’ he said. “So, while this may increase your water bill, it may be the cheapest cost long term when we look at overall water security.’’

There’s another angle to all this that has nothing to do with water quality. It’s a question of availability.

State law says reclaimed water is the property of the entity that produces it, according to Carol Ward, an assistant director of the Arizona Department of Water Resources. It has become more valuable, especially after the 1980 Groundwater Management Act was passed to reduce depletion.

Add to that, she said, a 1986 law that prohibits the filling of large bodies of water for landscape, scenic or recreational purposes. That increased the demand for treated effluent — the same effluent that communities are now being urged to recycle into drinking water.

“As water becomes more expensive and supplies are more limited, that will continue to shift how water is used,’’ Ward said. That will force local officials to make some decisions about the best use of the water — and whether processing it for drinking makes economic and environmental sense.

One of those decisions will occur in Tucson. The Tucson City Council went on record last month supporting the treatment of wastewater for drinking in the future. That puts the city in line with several other Southwestern cities that are looking at and, in some cases, already treating wastewater to drink.