Pollution in Tucson Water

Trichlorethylene (TCE), an industrial solvent, was routinely dumped in areas of South Tucson during the 1950s. The Tucsonans who lived in these areas have had various cancers as a result of this pollution.

The boundary of the area contaminated by TCE is roughly south of 22nd street, north of Los Reales Road, east of Interstate 19 and west of Del Moral Boulevard.

In 1981 the Environmental Protection Agency (EPA) tested water wells on the south side of Tucson and found TCE levels were beyond the EPA limits.

In 1983, the EPA set a large southside area of Tucson on its Superfund cleanup list.  In March 2000, a $35 million plan was secured for cleanup of the contaminated areas.  Other government supervised cleanups started about 20 years ago. The last settlements involving TCE lawsuits occurred in June 2006.

There is a free screening program for lymphoma, leukemia and multiple myeloma for people who lived in these areas.  To qualify for the program the person must have lived, worked or attended school for at least one year between 1954 and 1980 in the TCE contaminated area.  The free medical testing is through the El Pueblo Clinic.  For eligibility questions, call the clinic Monday through Friday at (520) 573-0096 ex. 116 or (520) 891-1791.

Timeline for TCE law suit

  • 1952: Hughes Aircraft starts using trichloroethylene to clean dirty or greasy metal parts at Air Force Plant 44, a government-owned missile factory south of the airport. Until the early 1980s, Hughes disposes of the TCE primarily by pouring it into open pits and occasionally by pouring it directly on the ground and down drains.
  • 1981: The Pima County Health Department finds serious soil and water pollution on the South Side resulting from industrial waste disposal practices. It closes all polluted water wells.
  • 1982: The U.S. Environmental Protection Agency adds the Tucson Airport Authority to its Superfund national priority list. The contamination covers an area approximately one-half mile wide and five miles long.
  • 1987: Soil and water cleanup begins.
  • 1989: The City of Tucson settles a lawsuit with 1,600 South Side residents for $35 million. Some of the insurers challenge their liability in the case.
  • 1991: Hughes Aircraft and other companies settle a lawsuit with 1,600 South Side residents for $84.5 million.
  • 1994: The Tucson Area Remediation Project, a treatment plant for contaminated water, begins full operation.
  • 1998: Hughes, now Raytheon Missile Systems Co., and other firms settle a suit in December with 247 residents. Two cases are still pending in federal court.
  • 2006: The last of three insurers agrees to terms with plaintiffs' attorneys, pushing the total settlement beyond $130 million.

Information Resources about this Site


In 2002, a carcinogen known as 1,4 dioxane was detected in Tucson’s groundwater, which was caused by pollution from the same compounds that contained TCE. The Air Force funded another treatment plant that opened in 2014 near the Tucson Airport Remediation Program plant (TARP), which was built in response to the TCE lawsuit. With the new treatment efforts, Tucson Water was able to keep dioxane levels below EPA standards since testing began.

PFAS in the Tucson Airport Remediation Program

In June 2021, the TARP plant shut down because it was unable to address the rising levels of per-and polyfluoroalkyl substances (PFAS). PFAS levels went up 700% from 2017 to 2021. PFAS was used in firefighting foam at the Air National Guard Base in the Tucson International Airport until 2018, and may have slowly made its way into the groundwater in the following years. PFAS compounds build up in the environment instead of breaking down, and may have health risks.

In May 2022, the TARP plant reopened. The contaminated water, after being treated for PFAS, was released into the Santa Cruz River with a permit from the EPA. Water treated at TARP will no longer be served as drinking water.


"Fears on TCE linger after years." Arizona Daily Star. April 19, 2003 Page B3.

"Last TCE settlement going to plaintiffs." Tucson Citizen.  June 9, 2006 Page A16.

Davis, Tony. “Why PFAS chemicals are rapidly rising in Tucson groundwater.” Arizona Daily Star. June 12, 2021.

Davis, Tony. “Soaring contamination causes shutdown of Tucson water treatment plant.” Arizona Daily Star, June 9, 2021.

Davis, Tony. “New plant to remove carcinogen from water.” Arizona Daily Star, July 7, 2011 / updated July 15, 2014.

“PFAS explained” | EPA.gov

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