El Paso Water has broken ground in Texas on the Pure Water Center, the nation’s first direct-to-distribution potable reuse facility.
Designed by Carollo Engineers and soon to be built by a joint venture of PCL and Sundt Construction, the project will treat secondary effluent from the Roberto R. Bustamante Wastewater Treatment Plant to produce up to 10 million gallons per day of high-quality purified water. The facility, on which work got underway last month, is expected to be operational by 2028.
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Unlike indirect potable reuse, which relies on environmental buffers such as reservoirs or aquifers, the Pure Water Center will introduce purified water directly into the potable distribution system. This sets it apart from the Colorado River Municipal Water District’s Big Spring facility in Big Spring, Texas, the nation’s first example of direct potable reuse. That project, launched in 2013, produces reclaimed water that is blended with raw surface water before undergoing conventional drinking water treatment.
The Pure Water Center will blend the purified water with up to 2 million gallons per day of treated brackish groundwater before delivering the water straight into the city’s drinking supply. According to Carollo, the blending step helps stabilize the finished water, reducing corrosivity before it enters the distribution system.
A legacy of diversification
The Pure Water Center is the latest step in El Paso’s long-standing commitment to diversifying water supplies for greater drought resilience. In its early years, El Paso relied solely on groundwater, but by the early 1900s, city leaders had become aware of the need to find additional sources.
“They recognized that for this town to survive in the water-scarce Chihuahuan Desert, all available water sources needed to be maximized,” said Gilbert Trejo, vice president of engineering, operations, and technical services at EPWater. “Mining groundwater aquifers alone wasn’t going to cut it.”
The first surface water treatment plant was built in the 1940s, but a devastating drought in the 1950s – when the Rio Grande all but dried up – ultimately led to a fundamental shift in how water was governed in El Paso. It marked a key milestone in the city’s water history.
“Parts of the town ran out of water,” Trejo explained. “That drove the need to remove politics from water resources planning. The city council established a dedicated Public Service Board that took charge of guiding El Paso’s long-term water supply strategy. It kicked into high gear our focus on building a diversified water portfolio.”
Over the ensuing decades, the city continued to expand its water sources for long-term water security. Conservation, nonpotable reuse, and additional surface water supplies were added to the water portfolio. EPWater also started an aquifer storage and recovery program using indirect reuse, built the Kay Bailey Hutchison Desalination Plant to treat brackish groundwater, and is developing a river water banking project to replenish local aquifers.
According to Trejo, DPR is the next evolution in EPWater’s reuse program and ongoing initiatives to develop local water resources. “Combined, our efforts have allowed us to survive in what is a perpetual drought-ridden environment,” Trejo said. “And we’re succeeding – the city is growing.”
Multiple barriers of treatment
To purify secondary effluent, the Pure Water Center will employ a multistage treatment process designed to exceed drinking water quality standards. The advanced purification technologies include membrane filtration, reverse osmosis, ultraviolet light with advanced oxidation and hydrogen peroxide, granular activated carbon, and chlorine disinfection.
“You can think of it as a castle defense,” said Sanaan Villalobos, vice president and project manager with Carollo Engineers. “It starts with membrane filtration – that’s our moat and initial barrier against particles, microorganisms, and viruses. Then, reverse osmosis acts as the castle wall, removing salts and organic chemicals. If anything makes it through, we have a fire-breathing dragon, also known as ultraviolet light with advanced oxidation and hydrogen peroxide, which destroys any remaining microorganisms and organic chemicals.”
Granular activated carbon is then applied to quench excess hydrogen peroxide from the previous step while serving as another barrier against organic chemicals. And finally, chlorine disinfection serves as the final barrier against microorganisms before purified water enters the potable distribution system, Villalobos explained.
While the treatment process itself did not necessarily present a challenge, the project’s timeline did. Carollo began design planning in 2017, but with completion not expected until 2028 because of a prolonged schedule, the team adopted a forward-looking approach to integrate the latest technologies while keeping the system adaptable for future upgrades.
“We designed an open-platform system that allows EPWater to update membranes over time as newer module designs become available,” Villalobos said. “In Texas, new membranes must first be piloted for approval by the Texas Commission on Environmental Quality, so we initiated pilot tests about two years ago to ensure the most up-to-date membrane technology would be in place when the facility opens.”
The Pure Water Center will include its own in-house research lab and pilot facility. With feed water from every plant process sent to the lab, EPWater can bring in membrane skids for ongoing pilot testing. Additionally, Carollo incorporated multiple sensor locations within the treatment system and across the facility, providing a plug-and-play approach for future integration of machine learning.
‘Tell your water story’
For IPR and especially DPR, gaining public trust is critical to project success.
“These projects tend to fail when there’s a lack of understanding about water resources, treatment, and the public water supply,” Trejo said. “That’s why outreach and education are so important.”
EPWater began public engagement early, during the project’s conceptual stage. The utility engaged the National Water Research Institute, which assembled an independent panel of experts in physical chemical treatment, water chemistry, microbiology, and public health to review the project design.
“The panel provided recommendations to ensure public health and safety, and that feedback was incorporated into the project,” Trejo said. “We also used it to demonstrate to the public the extent of our quality control and quality assurance – that the water we would be producing is safe and reliable.”
To further build trust, EPWater constructed a pilot plant to test the treatment process using the same source water that would feed the Pure Water Center. Customers were invited on facility tours to see the technology in action. “Being able to speak with experts and witness firsthand how the treatment process worked was instrumental in gaining public confidence,” Trejo said.
One of the most impactful aspects of the pilot facility was showing visitors the actual source water.
“Many assumed we were starting with murky, black water,” Trejo said. “When they saw that treated effluent was actually clear, it changed their perception and improved acceptance. It was a powerful visual.”
It also helps that in El Paso, acceptance is largely ingrained. Decades of public outreach have helped build awareness, making discussions about DPR easier. “We’ve been educating residents about water reuse since the 1990s,” Trejo explained. “Generations understand what it takes to secure our water future. This is life in El Paso.”
For other municipalities considering similar projects, Trejo offers straightforward advice: “Tell your water story.”
“Customers need to understand the history of water in their community – where it comes from, why it matters, and why they should care.”
