New EPA order could lead to Tucson PFAS pollution cleanup

In a potentially ground-breaking action, the EPA is ordering the Air Force and the Arizona Air National Guard to take what could be the first step toward a major cleanup of “forever chemicals” in groundwater on Tucson’s south side.

The Environmental Protection Agency told them to prepare a formal plan within a couple of months laying out how they will treat the water to insure it meets the agency’s recently enacted drinking water standards for various PFAS compounds — compounds known since 2019 to be polluting that groundwater. The plan must identify a “long-term treatment method” for the contamination, EPA’s order said.

The treatment must clean the water up thoroughly enough to allow that water to be “a source of drinking water by Tucson Water for its public water system,” EPA ordered.

The Air Force’s Plant 44 south of Tucson International Airport, and the Morris Air National Guard Base near the airport, have “caused or contributed to the endangerment” of city wells to the north by their use and/or disposal of PFAS compounds at both facilities, the agency said.

Air Force spokesman Mark Kincaid told the Arizona Daily Star, “The Department of the Air Force is committed to collaborating with our regulatory partners to protect human health and the environment. In that spirit we plan to meet with the Environmental Protection Agency to determine next steps.”

U.S. Rep. Raúl Grijalva of Tucson, who released EPA’s May 29 order to the public on Thursday, praised the federal action.

“I applaud EPA for taking this urgent action to make sure the U.S. Air Force and Arizona Air National Guard take responsibility for their actions that polluted our groundwater. This order makes it clear that full comprehensive abatement must no longer be delayed,” said Grijalva.

But former Tucson City Council member Steve Kozachik criticized the order because it doesn’t dictate an actual cleanup, complete with timetables for construction, installation and operation of equipment that would actually treat the water.

“We don’t need another plan; we need implementation,” Kozachik said.

EPA’s order targets for cleanup a section that contains a series of city wells that deliver contaminated water to Tucson’s water treatment plant on the south side. It’s called the Tucson Area Remediation Project or TARP. The wells haven’t been used for drinking. The city pumps out the water for delivery to the TARP plant.

From 2016 through 2024, samples of groundwater have been collected from the area of the treatment plant. They’ve shown contaminant levels exceeding EPA drinking water limits for several PFAS compounds by up to 5,300 times, the agency’s order said.

PFAS is an abbreviation for a group of commonly used, human-made chemicals known as perfluorinated and polyfluorinated alkyl substances that are very persistent in the environment and the human body, meaning they don’t break down easily.

The Air National Guard has acknowledged that it, like many other military departments around the U.S., used PFAS compounds regularly in firefighting foam nationally starting in 1970.

In 2019, an Air National Guard spokesman told the Star the base had gradually stopped using firefighting foam containing PFAS over the previous 2½ years.

The pollution has created “an unanticipated and unreasonable impact to Tucson Water’s operation of the TARP to ensure drinking water quality for the residents of Tucson,” EPA’s order said.

The order doesn’t appear to cover contamination known to occur directly underneath the Morris Air National Guard Base lying south of the wellfield area, or contamination, if there is any, tainting areas lying between the air base and the wells feeding the TARP plant.

Overall, the EPA ordered the Air Force and Air National Guard “to conduct measures to abate the actual and potential imminent and substantial threat to the health of persons presented by the presence of per- and polyfluoroalkyl substances (collectively ‘PFAS’)” in groundwater underlying the TARP water well field, “which serves as an important source of drinking water for the public water system that serves the City of Tucson.”

The order directs them to perform “evaluation, characterization and delineation of PFAS contamination and an evaluation of nature, extent and fate and transport of PFAS present in the aquifer.”

EPA is also ordering them to sample “public and private drinking water wells that are potentially impacted by PFAS,” along with a schedule for conducting the sampling and proposed measures to address PFAS levels that exceed federal drinking standards. It’s also requiring them to provide proposals for “addressing high concentration areas of PFAS to mitigate and minimize impacts to wells in the area.”

Tucson Water officials told the Star in a written statement Friday, “We are focused on seeing real action to address the groundwater PFAS contamination as soon as possible.”

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But, “it is impossible to predict when this resource could be used for the potable system until groundwater remediation treatment is in place, operational, and proven to be effective,” the utility said, referring to its TARP plant.

Kozachik, who has pushed hard for a PFAS cleanup, said the order is “not responsive to the urgency of the issue.”

It contains no terms dictating “when actual treatment facilities will be up and operational,” he said.

“This is simply more of the slow walk the federal government has been engaging on the whole PFAS issue since it became public,” said Kozachik, who at the end of March resigned from the council after nearly 15 years to take a job as Pima County’s “point of contact in managing” the planned Mosaic Quarter sports complex, scheduled to go online in 2027.

He also noted the EPA order doesn’t address cleanup of a separate area of PFAS contamination in midtown Tucson, lying just north of Davis-Monthan Air Force Base.

An EPA spokesman, Joshua Alexander, said Friday the agency was not yet able to respond to questions from the Star about whether its order will mean a prompt groundwater cleanup. He said agency officials should have more information this coming week.

The statement from Tucson Water officials said they appreciate “that the administrative order is a step toward the eventual remedy for removing existing contamination in the regional groundwater and protection of uncontaminated areas, but the timeline, cost, and regional scope of such a project is far beyond the purview of this administrative order.”

A separate, planned city-run facility to remove PFAS from south-side groundwater has already received $25 million in federal money. The funds were funneled more than two years ago through the Arizona Department of Environmental Quality. At the time the money was awarded in late 2022, officials acknowledged the project would not cover the entire cost of the area’s groundwater cleanup.

Tucson and ADEQ have spent the past two years designing and preparing to build the facility. It must be in operation by 2026 under the terms of the federal funding from the pandemic-era, $1.9 trillion American Rescue Plan Act.

“In contrast, the Air Force has not participated in this effort,” Tucson Water told the Star. “The City of Tucson hopes that the Air Force will join this effort, or otherwise respond quickly and responsively to the order, but we have no authority to promptly compel them to do so.”

The utility added, “The most important outcome of the Administrative Order would be a conversion of the Air Force from a non-participant in the longstanding existing PFAS remedial effort currently centered around the TARP wellfield, to a willing PFAS partner at the site. Whether that outcome happens is entirely up to the Air Force.”

The purpose of EPA’s order is to ultimately restore the TARP plant’s ability to treat polluted water well enough that it can be used for drinking.

The plant, located near Irvington Road and Interstate 19, has removed two other toxic compounds from south-side groundwater — trichloroethylene and later, 1,4-dioxane, starting in 1994. Until 2021, the water treated by that plant was sent into the utility’s drinking water system to be served to homes and businesses.

But in June 2021, Tucson Water temporarily shut down the plant upon discovering that PFAS levels in nearby test wells had risen rapidly in recent years, and threatened to overwhelm the plant’s ability to remove those contaminants.

The plant was put back into service about five months later. But the treated water is now either discharged into the neighboring Santa Cruz River or diverted by pipeline into the city’s reclaimed water system to be put on parks, golf courses and school playgrounds, among other uses.

The effect of PFAS on the TARP plant’s granular activated carbon filters “has created an unanticipated and unreasonable impact to Tucson Water’s operation of the TARP to ensure drinking water quality for the residents of Tucson,” EPA’s order said.

The plant’s treatment system serves the dual purposes of peroxide quenching to remove the dioxane and PFAS adsorption, EPA said. Because of that, the agency said, the carbon treatment system’s life is significantly reduced, requiring replacement of the carbon filers multiple times per year, as opposed to every three to five years.

The need to replace the carbon filters will become more frequent “as the PFAS plume continues to migrate further across the TARP wellfield and remedial action to address PFAS contamination has not yet occurred,” the agency’s order said.

Since the $25 million in federal dollars was awarded, Tucson and ADEQ officials have prodded the Defense Department to pump more funds into the cleanup.

While the city doesn’t need the south-side groundwater to meet its current drinking water needs, officials have said they may well need it in the future if Tucson’s Central Arizona Project supplies from the Colorado River are cut substantially due to drought and climate change.

Major CAP cuts could be required as early as 2027, following the completion of ongoing negotiations among the seven Colorado River Basin states for an agreement on how to manage river operations after a current agreement expires at the end of 2026. At this time, it’s not known if that agreement will trigger major cuts in Tucson Water’s share of CAP supplies.