PHOENIX — An Arizona city is suing the federal government, claiming toxic PFAS "forever chemicals" released from a nearby Air Force base are causing ongoing contamination of the city’s drinking water supply.

In a lawsuit filed Monday, the city of Tucson said it wants compensation for the damages caused by PFAS, or per-and polyfluoroalkyl substances, released at the Davis-Monthan Air Force Base. The city also wants the Air Force to pay or reimburse the cost of a treatment system to remove PFAS from incoming untreated water.

The lawsuit comes after the U.S. Environmental Protection Agency ordered the Air Force and the Arizona National Guard in May to take action after high concentrations of PFAS were detected in the groundwater of a historically contaminated area on Tucson’s south side. The cleanup was ordered for properties near the Tucson International Airport at the National Guard base, and a property owned by the Air Force.

The EPA gave the Air Force 90 days to design a long-term water treatment method. In July, the Air Force sent a letter asking the EPA to withdraw the order.

The letter noted that the order "cannot result in the elimination of PFAS contamination in the aquifer any faster" than the federal cleanup process already taking place, nor any faster than Tucson’s project to build a PFAS pretreatment plant. The Air Force maintained it was “fully committed” to its ongoing PFAS response, including restoration of the Tucson aquifers.

The Air Force pointed to a $25 million federal grant from the state to build a new PFAS pretreatment plant for the Tucson Airport Remediation Project, also known as TARP. The letter also highlighted funds it has paid to TARP, including millions of dollars for the initial plant in 1991 and $17 million in 2016 for the new Advanced Oxidation Process facility.

In October, the EPA determined the Air Force complied with the May order after the military branch outlined a plan to take action, including collecting data to determine the extent of contamination, conducting pilot studies for possible cleanup, and working with Tucson’s water utility to cover past and future costs for PFAS treatment at TARP.

But in Tucson’s lawsuit this week — which names the U.S. as the defendant in the case — the city alleged that the Air Force base had "taken inadequate action to stop or mitigate the ongoing migration of its PFAS contamination into Plaintiff's water supply and any assistance (financial or otherwise) it has agreed to provide will not continue for as long as necessary."

The U.S. Attorney’s Office did not respond to The Arizona Republic's, part of the USA TODAY Network, requests for comment.

See our map.Is your water system among hundreds that reported PFAS above new EPA limits?

Tucson has been reporting PFAS contamination for more than a decade

The city first reported the chemicals in 2013 after it found an average of 28 parts per trillion of PFAS in a well Tucson relied on for its water. By January 2017, the contamination reached 79 parts per trillion. Later that year, contamination levels increased to 133 parts per trillion, and 97 parts per trillion in March the following year.

The recommended level of PFAS is between 4 parts per trillion and 10 parts per trillion.

That well was taken offline and has been unused ever since. Thirty other wells were also removed from service because of the contamination. The city also said it invested in specialized laboratory equipment to analyze over 1800 samples for PFAS each year.

Tucson’s water utility, Tucson Water, stopped serving water treated at the TARP to residents in 2021 when increased PFAS levels caused the plant to temporarily shut down as the filter system sequestering the contaminants could not handle the increase.

While Tucson maintains that the water it serves to the public is safe to drink, it also notes the contamination has impacted trust in the city's water supply. The water treated at the TARP facility isn't served as drinking water, it is instead it to the Santa Cruz River to maintain water levels and help with riparian habitat restoration.

Tucson alleges it has spent a total of $71.1 million on remediation costs and blames the Air Force for using PFAS-based aqueous firefighting foams to extinguish fuel-based fires for decades, releasing contaminants into the environment. Other damages Tucson says it has incurred include loss of water production capacity and diminished consumer confidence in the city’s water.

The Air Force “knew of the contamination of its groundwater with PFAS and consciously disregarded a known risk that the contamination had already migrated off-site and into Plaintiff’s wells, or that such risk was imminent,” the city alleges in its complaint.

The city claims the Air Force is creating a public nuisance by failing to mitigate the PFAS contamination from the soils and groundwater into city wells. Tucson attorneys also allege the Air Force breached its duty to warn the city that hazardous chemicals would likely be released and that the migrating contamination onto Tucson property constitutes trespassing.

What are PFAS?

PFAS are long-lasting chemicals that have been used since the 1940s in a wide range of industries and products — from fire retardants and popcorn bags to personal care items and clothing — that can now be found globally in water. PFAS are considered hazardous substances that can cause severe health issues with long-term exposure, even in low traces.

Studies show PFAS exposure can negatively impact the body’s immune and cardiovascular systems, as well as vaccine response. Studies have also linked oral exposure to PFAS to adverse health effects on the liver, the kidneys, and the immune system, and cancer, according to the EPA.

USA TODAY reported earlier this year that tens of millions of Americans get their water from a system where PFAS were found at levels that require reporting to the EPA. Over 600 systems across the U.S. have measured PFAS levels at or above the newly established limits since last year, according to a USA TODAY analysis.

Contributing: Austin Fast, Cecilia Garzella, and Yoonserk Pyun, USA TODAY

Reach the reporter at [email protected]. The Republic’s coverage of southern Arizona is funded, in part, with a grant from Report for America.Support Arizona news coverage with a tax-deductible donation at supportjournalism.azcentral.com.

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