How Cave Creek Water Reclamation Plant shores up supplies

In March, the City of Phoenix celebrated the progress made on the construction of its Cave Creek Water Reclamation Plant. Now 50% complete, the project is part of the Pure Water Phoenix plan — an initiative to deploy advanced water purification systems to shore up the municipality’s drinking water supply.  

“As we move into a period where we have less surface water available to the city — especially through the Colorado River, but maybe someday from the Salt and Verde River systems too — it’s critical that we get the most benefit possible out of every drop of water,” explains Max Wilson, water resources management advisor for the City of Phoenix.  

The technology coming to the Cave Creek Water Reclamation Plant enables the city to clean wastewater to the point where it is “as clean or cleaner” than all the water being sent to residents today, Wilson continues, adding that minerals have to be added back in to meet customer taste expectations and protect the pipes the water is delivered through.  

“We use a multistage filtration process, much like a reverse osmosis system you may have at home,” he says. “It’s the cleanest water available in our entire distribution system.”  

The plant will initially produce nearly 7 million gallons of purified drinking water each day — enough water to serve 25,000 households — and has the capacity to double that output as demand increases. The Cave Creek facility is one of three water purification projects envisioned within the City of Phoenix. 

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Construction on the plant is slated to complete at the end of 2027, followed by approximately one year of testing and verification procedures before the purified water can be delivered to homes. Wilson says residents in the area can anticipate receiving these supplies by early 2029. 

Old facility, new purpose  

Even though the Cave Creek Water Reclamation Plant just reached the halfway point on its construction schedule, the facility itself has been in the community for decades. Nazario Prieto, assistant water services director for the City of Phoenix, explains that municipal leadership planned for the site to eventually become the city’s first advanced water purification plant back in the late ‘90s.  

“At the time, advanced water purification was banned in Arizona, but city leaders knew that one day that would change and we’d need [this technology],” Prieto continues.  

But when the Great Recession hit, the decision was made to mothball the plant after being operational for about 10 years. The site lay dormant until the city identified that the surrounding area was running out of conveyance capacity.  

“Around 2017, we brought in a design consultant,” Prieto says. “Advanced water purification was still prohibited, but we felt like that was going to change, and one year later it did. That allowed us to move forward with a plant design that incorporated the elements needed for us to do advanced water purification in the future.”  

Since the regulations around distributing advanced purified water to residents were still being written at that time, Prieto notes that the city had to make an educated guess on what the requirements would be.  

“We went with a full reverse osmosis ultraviolet advanced oxidation process,” he continues. “Once the rules came out in 2025, we only needed to add a few little things.”  

Wilson acknowledges that the idea of drinking treated wastewater may sound off putting to some people but reiterates that the process is backed by science and produces the highest purity water in the municipality’s portfolio.  

“If that’s not enough for folks, consider that some of our most senior water executives and city leadership live [near the Cave Creek Water Reclamation Plant] — including myself,” he concludes. “We’ll be among the first people to actually drink this water.”