Fort Indiantown Gap

Fort Indiantown Gap is a National Guard training installation in eastern Pennsylvania, located primarily in Lebanon County and extending into Dauphin County. It is operated by the Pennsylvania Department of Military and Veterans Affairs and serves as the primary training site for the Pennsylvania Army National Guard, supporting live fire ranges, aviation training, and mobilization activities. The post traces its origins to the 1930s and has grown into one of the busiest such centers in the country. Over the decades it has hosted a wide range of military exercises, equipment operations, and emergency response missions for federal and state forces.

Like many installations where firefighting operations and aircraft training have taken place, Fort Indiantown Gap has been associated with concerns about potential exposure to a group of synthetic chemicals collectively known as per- and polyfluoroalkyl substances. In 2019 the installation was added to the Pennsylvania Department of Environmental Protection list of military and industrial sites where PFAS have been found. Reporting at the time indicated that PFAS were first detected in 2017 in a single well in the base training corridor, at a level below three parts per trillion and below the federal health advisory level then in effect. The substances below have been discussed in connection with activity at this base.

1. PFAS: PFAS are a large family of manufactured chemicals valued for their resistance to heat, water, and oil, which also makes them slow to break down in the environment. At Fort Indiantown Gap, PFAS have been reported in groundwater in the area of training and firefighting operations. Research has associated certain PFAS exposures with a range of potential health effects, and concerns about long term exposure continue to be studied.
2. PFOS: PFOS is one of the most studied individual PFAS compounds and was a common ingredient in older firefighting foams. It is among the substances generally of concern in PFAS investigations at sites of this kind. PFOS has been associated in some studies with effects on the immune system and other health endpoints, though findings continue to be evaluated.
3. PFOA: PFOA is another widely studied PFAS compound historically linked to firefighting foam and industrial uses. It is among the PFAS compounds commonly tracked in environmental investigations of this type, and its long term effects remain a subject of ongoing research.
4. AFFF: AFFF, or aqueous film forming foam, is a firefighting agent used to suppress fuel based fires and is a recognized source of PFAS, including PFOS and PFOA. The legacy use of firefighting foam at military training sites is widely understood to be a common source of PFAS found in area groundwater. Because AFFF contains the compounds described above, concerns about potential exposure relate to the same body of health research.

Fort Indiantown Gap is not listed on the federal National Priorities List as a Superfund site. Environmental investigation and cleanup are being carried out under the federal CERCLA process and Pennsylvania state oversight, with documents including a Preliminary Assessment (2018), a Site Inspection Report (2021), and a Remedial Investigation work plan (2024). A 2026 review of Pentagon cleanup timelines reported that PFAS remediation here had been pushed back by roughly 13 years, with a benchmark moved toward 2043, part of a broader pattern of delays across military sites.

Veterans, National Guard members, and others who trained or worked at Fort Indiantown Gap may wish to stay informed as environmental investigation and cleanup continue. Those with questions about possible exposure are encouraged to speak with the U.S. Department of Veterans Affairs and their own health care providers, who can offer guidance based on individual circumstances and the most current information available.