The Tucson International Airport Area covers ten square miles in southeastern Tucson, Arizona, and has been on the National Priorities List (NPL) since 1983. The site includes the airport, residential neighborhoods, Air Force Plant 44 (AFP 44), and parts of the Tohono O'odham Nation's San Xavier District. Contamination came from aircraft and electronics manufacturing, aircraft maintenance, fire drill training, and leaking chemicals from unlined landfills. As of 2023, the most recent five-year review has been completed, but construction is not finished and the site remains on the NPL.
The main contaminants in groundwater and soil are trichloroethylene (TCE) and other volatile organic compounds (VOCs), 1,4-dioxane, per- and polyfluoroalkyl substances (PFAS), polychlorinated biphenyls (PCBs), heavy metals such as chromium, lead, cadmium, nickel, and arsenic, and additional solvents and chlorinated compounds. Groundwater contamination is the primary concern. Contaminated groundwater continues to move in the subsurface because migration has not yet been stabilized.
Cleanup is organized into six operable units (OUs). The Tucson Airport Remediation Project (TARP) treatment system has removed over 5,000 pounds of TCE from the aquifer. A landfill was capped in 2011, and contaminated soils and pipeline sludges with high PCB levels were excavated and removed. Advanced oxidation treatment systems were added at AFP 44 in 2008 and at TARP in 2014 to address 1,4-dioxane and VOCs. TARP added granulated carbon treatment for PFAS in 2019. PFAS contamination has prevented the City of Tucson from using treated water for drinking. In May 2024, EPA issued an order to the U.S. Air Force and Air National Guard to develop a water treatment plan for PFAS. In September 2024, EPA reached an agreement with the Tucson Airport Authority to address PFAS in the Tucson aquifer. A feasibility study for groundwater began in December 2024, with completion estimated between August and October 2026. Human exposure across the entire site is currently under control, with no known private well users drinking contaminated groundwater.
Beyond cleanup, the site supports active economic use. As of December 2024, 79 businesses operate there, employing over 11,000 people and generating roughly $4.5 billion in annual sales.
Community members can get involved through the Unified Community Advisory Board (UCAB), established in 1995. UCAB holds free, public quarterly meetings in person and online. 2026 meetings are scheduled for January 21, April 15, July 15, and October 21, all starting at 6:00 p.m. To get meeting information, contact UCAB or the EPA Remedial Project Manager. Site documents are available at the Valencia Library in Tucson, the EPA Region 9 Records Center in San Francisco, and ADEQ offices in Phoenix and Tucson.
