The KJZZ series "Every Last Drop" tackles big questions about Arizona's water future — including what Arizonans can do to make a difference and what’s being done to keep the state's water safe.
Published: May 17, 2023
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This year, the Environmental Protection Agency proposed formal limits on certain types of perfluorinated and polyfluorinated substances, known as PFAS.
Like in other cities, the chemicals have been found in high concentrations in Tucson recently, and water authorities have had to respond. But the city is no stranger to groundwater contamination, or community efforts to confront it.
PFAS are a group of thousands of human-made chemicals used in consumer and industrial products. Exposure has been linked to health issues like cancer and liver damage.
Bo Guo, an assistant professor of hydrology and atmospheric sciences at the University of Arizona, says the chemicals have been around since at least the 1940s. They’re used in everything from nonstick pans to waterproof jackets, and most do not break down naturally.
By now, Guo says, they’re everywhere.
“We see PFAS in this room and probably in our blood,” he said.
They’re also in a product called Aqueous Film Forming Foam, known as AFFF. It’s been used to put out fuel fires at air bases and airports.
The EPA says PFAS have been found in air, fish, soil and water around the globe. But the chemicals are not federally regulated.
The EPA's new proposal aims to change that by limiting six of the most well-known PFAS in drinking water. That includes PFOS and PFOA, which the agency proposes limiting to four parts per trillion.
It's considered a landmark proposal that could formalize PFAS regulation and testing in states. Guo says it’s an encouraging step, but it’s important to understand the scale of contamination — cleanup could take decades.
“We're just at the starting point of PFAS,” he said. “You know, it's not gonna be done in a few years … because it's so complex, it's so ubiquitous, you know, they are everywhere.”
Yolanda Herrera knows what that timeframe looks like up close. We met at a community garden on Tucson’s south side that’s shaded by old trees.
“Today we are enjoying the peace of the Peace Garden that's located in the Manuel Herrera Jr. Park, named after my dad,” she said.
The park is a calm respite from the noisy skies above. We’re a few miles away from the Tucson International Airport and the Air National Guard base. Davis-Monthan Air Force Base and another Air Force facility are also nearby.
Herrera was born and raised not far away from here. She’s a fifth-generation Tucsonan.
“So people always say, well, if you didn't like the jets, why did you move here? Excuse me. We were here before,” she said.
But as more industry moved in, water contaminants came alongside it. This area has a painful history because of a toxic compound called trichloroethylene, or TCE.
During the 1950s, defense contractors, military bases and national guard facilities clustered around here used it in a cleaning solvent for jet engines and other metal parts.
The solvent ended up contaminating the groundwater that fed taps, pools and surface water in neighborhoods nearby, like Herrera’s, when it dumped improperly in places like storm drains and open pits.
She’s watched a lot of loved ones get sick.
“So when people tell us that it's not generational, they can't prove it by us,” she said. “I mean, we can show them the generations who have died, including my mom's dad died of cancer.”
Today, Herrera is the president of the Sunnyside Neighborhood Association, and she’s also at the helm of a community effort started decades ago by her dad, Manuel. He was one of the first to raise the alarm about the contamination and demand federal action.
He was a U.S. Navy veteran who Herrera says got involved in community advocacy after he retired from his job at the post office and started noticing that a lot of his neighbors were getting sick.
“Some of them, extremely young,” she said. “I believe it affected my age group the hardest because we were, our bodies were just forming … we just had our 52nd high school reunion. And to see all the names of the people we lost was just really powerful.”
The area became an EPA Superfund site in 1983. The Unified Community Advisory Board was established more than a decade later, 1995, to give community members and the public a chance to hear how cleanup was going. Herrera’s The area became an EPA Superfund site in 1983. The Unified Community Advisory Board was established more than a decade later, 1995, to give community members and the public a chance to hear how cleanup was going. Herrera serves as the community co-chair of the board.
The Superfund designation allowed the EPA to identify the parties that caused the contamination and make them responsible for the cleanup.
It also led to the creation of the Tucson Airport Remediation Project water treatment plant. It’s a big, buzzing warehouse a few miles from the community garden and the airport.
“This is the location on Irvington near the Santa Cruz river where since 1994, the city of Tucson has been treating groundwater contaminated with TCE,” Tucson Water Director John Kmiec said on a recent tour of the facility.
The plant has also started treating another industrial compound called 1,4-dioxane, and even more recently, for PFAS.
“We take the recovered groundwater that’s contaminated with TCE and 1,4-dioxane and that water all comes to this location and hydrogen peroxide is added to the water to oxidize those organic chemicals,” he said.
This is a process called advanced oxidation. A giant blue pipe carries untreated water to another set of silver tubes inside the warehouse. After that, the water heads to a high intensity ultraviolet light that shatters what’s left of the contaminants.
The final step is a set of white tanks just outside the warehouse that contain carbon filters. It’s meant to remove the hydrogen peroxide, but it can also treat for PFAS.
That process was enough to produce quality drinking water. Until 2021, when the level of PFAS coming into the plant spiked.
“Our analysis is it’s the AFFF, the Aqueous Film-Forming Foam that’s been used at the airport property for decades, it’s what has contaminated the groundwater, and that slow contamination is what’s moving into our well fields,” he said.
More than two dozen wells around Tucson were shut down after that. Operations at this facility also came to a halt. Today, the plant has switched from producing drinking water, to reclaimed water. Kmiec says the spike in PFAS have made reaching drinking water quality cost prohibitive with the carbon filters.
Plans are underway now to construct a new facility for PFAS treatment using a $25 million grant awarded to Tucson by the Arizona Department of Environmental Quality.
But unlike the old TCE cleanup at this plant, which the Defense Department helped fund, the city of Tucson has mostly covered the cost of testing for, and cleaning up, PFAS contamination.
Kmiec hopes the new EPA limits will bring federal dollars to the effort, and require parties responsible for the contamination to help address it.
But, as Herrera knows, these are long fights.
Back at the garden, she leads the way to a big red block with a quote written on top that reads, "your actions today affect your tomorrows."
“This is one of my favorite messages that I always try to show people because it's very powerful,” she says. “That holds true for anything.”
Herrera says she first heard about PFAS when her 9-year-old granddaughter was born. Now, the chemicals are a mainstay discussion at the community meetings she helps lead. She says she wants to make sure the next generation doesn’t deal with the same consequences as hers did, with TCE.
“They'll never fix it. They'll never bring these people back. But we certainly are working so that it never happens again,” she said. “And that's why researching the PFAS and making the government do stronger regulations against that is so important. We don't want it to take another 20, 30 years before they determine that it's a carcinogen.”
Explore all the stories in KJZZ's 'Every Last Drop' series→ Arizona's water supply is shrinking, but its population is growing. Is it sustainable?
→ Groundwater is critical to rural Arizona — but there's a struggle to regulate it
→ Is drought in Arizona and the Southwest the new normal?
→ To better understand Arizona's water supply, we retrace its origins
→ How much can at-home conservation impact Arizona's water shortage?
→ How Scottsdale's drought plan has reduced the city's water footprint
→ Gray water’s untapped potential is clouded by complexity
→ As drought worsens, will Arizonans see higher water bills?