U.S. Air Force Plant 44

U.S. Air Force Plant 44 is a federally owned, contractor operated missile manufacturing facility about eight miles south of downtown Tucson, Arizona, bordered to the north and east by Tucson International Airport. It has been operated by Hughes Aircraft Company since the early 1950s and is now run by Raytheon Missile Systems, producing guided missiles and related defense electronics. Across more than seven decades, the roughly 1,365 acre facility used and disposed of metals, chlorinated solvents, and other industrial substances. Because of contamination found in the regional aquifer, the plant became part of the larger Tucson International Airport Area Superfund site, added to the National Priorities List on September 8, 1983. The site is now addressed through a long running cleanup effort involving the Air Force, Raytheon, the U.S. Environmental Protection Agency, and the Arizona Department of Environmental Quality.

Investigations at the plant and surrounding area have documented several contaminants in soil and groundwater that raise concerns about potential exposure for nearby residents, workers, and military personnel. The substances below have been identified in connection with operations at or near the plant.

1. Trichloroethylene (TCE): TCE is a chlorinated solvent used at the plant to clean and degrease metal missile parts. It migrated into the regional aquifer, where reported concentrations have ranged up to about 1,520 parts per billion against a federal drinking water standard of 5 parts per billion. Exposure to TCE has been associated in scientific literature with a range of health concerns, and it remains a primary focus of the groundwater cleanup.
2. 1,1-Dichloroethene (1,1-DCE): This volatile organic compound is identified among the principal contaminants of concern in the regional groundwater and can form as TCE breaks down. Concerns have been raised about potential exposure through contaminated drinking water sources.
3. 1,4-Dioxane: This solvent stabilizer was detected in the migrating groundwater plume associated with the facility. It is difficult to remove with conventional treatment, and exposure to it has been associated with potential health effects in regulatory assessments.
4. Chromium and other heavy metals: Chromium is listed among the documented contaminants of concern, reflecting the use and disposal of metals during manufacturing. Some forms of chromium and other heavy metals have been associated with health concerns when present in drinking water.
5. Per- and polyfluoroalkyl substances (PFAS): PFAS are persistent man made chemicals more recently detected at high concentrations in groundwater connected to the plant and the adjacent Air National Guard base. In 2024 the EPA issued orders directing the Air Force and the Arizona Air National Guard to address PFAS migration, and the Air Force agreed to investigate PFAS releases under the federal Superfund law. Concerns about potential PFAS exposure relate to its persistence in water and the human body.

Cleanup has been underway for decades. After volatile organic compounds were identified in the aquifer in the early 1980s and the city closed affected municipal wells, the Air Force issued a Record of Decision in 1985, and a large scale pump, treat, and reinjection system began operating in 1987 to contain the regional groundwater plume. A Federal Facility Agreement signed in 2011 committed the Air Force to remediate Air Force owned property, and PFAS investigation and response work has continued under EPA oversight as part of the Superfund site.

Veterans, civilian workers, and family members who spent time at or near U.S. Air Force Plant 44 may wish to stay informed as cleanup and PFAS investigations continue. Those with questions about possible exposure are encouraged to keep records of their service and to consult the U.S. Department of Veterans Affairs regarding current health resources and benefits guidance.