By Philip Haldiman
Mail | X: @PhilipHaldiman

As Arizona’s water crisis sees no end in sight, the city of Phoenix is working on a “drought proof” option for the future, and they hope other Valley cities and towns jump on the bandwagon.

The plan involves adding a new option to their water portfolio — transitioning treated wastewater into high-quality drinking water.

Phoenix has plans to build a proposed regional advanced wastewater purification facility at the existing 91st Avenue Wastewater Treatment Plant in south Phoenix that could accomplish this.

The plan is still in the early stages but Phoenix has invited at least nine other Valley municipalities and EPCOR Water Arizona to enter into a non-binding agreement to investigate the possibility of this proposed facility.

This $7 billion to $10 billion investment probably won’t completely come to fruition for 10 years, but Phoenix Mayor Kate Gallego said at her April state of the city address that the Phoenix City Council unanimously approved the first step to formalize the collaboration with Valley cities to advance the development of the wastewater facility.

“By augmenting our existing 91st Avenue facility with advanced treatment technology, we will recycle around 60 million gallons per day upon completion,” she said. “This is a multi-billion dollar investment. I’m proud that Phoenix is driving effective pragmatic solutions with proven technology to deliver big solutions by the end of the decade.”

Gaining Support

During the past month, city and town councils have considered a memorandum of understanding to share the costs of the study and plan. Municipalities also would explore potential governance options for a regional facility and examine water management tools and arrangements that could extend the benefits of a regional plant to the maximum extent possible throughout the region and state, documents said.

The MOU is a non-binding agreement.

So far, El Mirage, Glendale, Mesa, Peoria, Scottsdale and Tempe, as well as EPCOR, have approved the agreement. Gilbert, Tolleson and Goodyear have been invited but have not yet approved the agreement.

The Peoria City Council approved the agreement on Aug. 15.

“This MOU is another example of Peoria’s top priority to secure our water future,” Mayor Jason Beck said. “I’m pleased Peoria is leading water policy innovation by exploring a regional advanced water purification facility that would increase our water independence.”

Once Phoenix has all approved agreements, the city will begin to form steering committees and move toward implementing the feasibility study.

Nazario Prieto, assistant director for the Phoenix wastewater division, said the next milestone would be funding the study, which would determine cost estimates and cost sharing with all municipalities involved.

“At the end of the day, we don’t know if it will be Phoenix with one or two or three other cities. But (the study) lets us get as many municipalities to work with us now to find out if this will be beneficial and makes sense for their water portfolios,” Prieto said. “We won’t know until we get into the nitty gritty and the size of the facility who is going to participate, or if we will need additional infrastructure. Other stuff needs to be answered before we move forward.”

Trying to be drought-proof

The 91st Avenue Wastewater Treatment Plant, located just north of the Salt River in southwest Phoenix, is a regional facility co-owned by five cities — Phoenix, Mesa, Tempe, Scottsdale and Glendale. Phoenix owns the majority of the facility and is the operator.

Much of the reclaimed water from the plant is sold to the Palo Verde Nuclear Generating Station, where it is reused in cooling towers, providing an important nexus between water and power in the state, according to officials.

The proposed advanced water purification facility would be on this site and take high-quality reclaimed water from the existing wastewater plant and treat it further to meet potable standards, turning the reclaimed water into a drought-proof drinking water supply — sometimes referred to as Advanced Water Purification, documents say.

A water supply like this is important because it can create a closed cycle, making a supply sustainable, Prieto said.
“A drought-proof drinking water supply is a supply that keeps coming to us. With drought proof, we are still able to provide water and if we continue to do that, we continue to get wastewater in return. In a major drought we will restrict water use outside, but water use inside homes keeps coming back to us.”

Writing the Rules

AWP leverages a multiple-barrier treatment approach to remove pathogens and chemical contaminants. Examples of AWP treatment processes include purifying treated wastewater using combinations of reverse osmosis or ozone, biologically active carbon filtration and other processes, such as advanced oxidation.

Alma Suarez, deputy public information officer for water quality at Arizona Department of Environmental Quality, said AWP stands as an innovative application of those proven water treatment methodologies designed to convert treated wastewater into safe, reliable purified water.

“AWP includes constant monitoring and testing throughout the entire process for various parameters to meet strict water quality standards and ensure the production of high-quality, safe, purified water for consumption and other uses,” she said.

Prior to 2018, the state of Arizona prohibited using treated wastewater for potable consumption. Now it is allowed, however rules and guidelines to facilitate using AWP have not been completed.

ADEQ officials have worked on this initiative for more than a year, following a directive from the Arizona Legislature to help secure the state’s water future by making AWP an option for water systems.

Prieto said the new rules and guidelines, or AWP Roadmap, should be completed by 2024, which will be another big milestone toward AWP.

“If you look across the southwest — California, Texas, Colorado — we are all moving in that direction,” he said.

The proposed AWP Roadmap will include detailed descriptions of the AWP program and processes for producing high-quality, safe, purified water, including operation and maintenance, monitoring and testing, enhanced quality controls and permitting.
Suarez said the roadmap will be a resource for stakeholders to understand ADEQ’s approach to AWP implementation in Arizona.

There will be a formal public comment period and hearing for the roadmap, then the Governor’s Regulatory Review Council will have final approval following which, facilities such as the proposed advanced wastewater purification facility at 91st Avenue would need to seek approval from ADEQ and meet all AWP regulations.

“Just like water conservation, water recycling and other sustainable water management practices, AWP is a part of Arizona’s long-term strategy to ensure a safe and adequate drinking water supply sufficient to support Arizona’s existing and future population,” Suarez said.

Philip Haldiman can be reached at phaldiman@iniusa.org, or on Twitter @philiphaldiman. We’d like to invite our readers to submit their civil comments, pro or con, on this issue. Email AZOpinions@iniusa.org.

Philip Haldiman
News Editor | Peoria

phaldiman@iniusa.org

Philip Haldiman is a third generation Arizona native with brief residencies on the east and west coasts. He has bachelor’s degrees in Theater and Journalism at Arizona State University, and is an award winning journalist with more than 15 years worth of experience in reporting and editing. Most recently, he took first place for investigative reporting and third place for best sustained coverage or series at the 2023 Arizona Newspapers Association awards. In his free time, he produces an autobiographical comic book about his time spent in Hollywood and his life as a cult film star.