Otis Air National Guard Base/Camp Edwards

Overview

Joint Base Cape Cod, also known as Otis Air National Guard Base and Camp Edwards, covers 22,000 acres in Falmouth, Massachusetts, about 60 miles south of Boston. The base sits over a sole source aquifer that supplies drinking water to roughly 200,000 year-round residents and 500,000 seasonal visitors. Past military activities, including fuel spills, chemical disposal, and weapons training, contaminated soil and groundwater across dozens of areas. The site was added to the National Priorities List in November 1989, and cleanup has been active ever since.

Contamination includes volatile organic compounds such as trichloroethene, tetrachloroethene, benzene, and vinyl chloride, along with chlorinated solvents, heavy metals like arsenic, lead, and chromium, pesticides including DDT and dieldrin, and petroleum hydrocarbons. These contaminants appear in groundwater, soil, sediment, and surface water across more than 34 distinct areas called operable units. Recent investigations also identified PFAS and 1,4-Dioxane as emerging contaminants at the site.

Two separate cleanup programs operate here. The U.S. Air Force runs the Installation Restoration Program at Otis Air National Guard Base under Superfund authority. The U.S. Army runs the Impact Area Groundwater Study Program at Camp Edwards under Safe Drinking Water Act authority. Both programs work under EPA and Massachusetts Department of Environmental Protection oversight. The Air Force has spent $67 million on off-base drinking water protection, including bottled water delivery, well treatment, home connections to extended waterlines, and in-home filtration. About 100,000 tons of contaminated soil have been treated. Four groundwater plumes at Otis are being extracted and treated at roughly 5.4 million gallons per day, while seven plumes at Camp Edwards are treated at 3.0 million gallons per day, totaling about 10.6 million gallons daily across the site.

Cleanup construction was completed in December 2009, and the site achieved sitewide ready for anticipated reuse status in June 2010. Human exposure is under control, and contaminated groundwater is stabilized with no unacceptable discharge to surface water. Monitoring continues to confirm groundwater stays contained. Two recent Records of Decision, covering the Old Grenade Courts and Old K Range areas, were finalized in July and August 2025, showing that active cleanup decisions are still being made for some portions of the site. Institutional controls such as zoning restrictions and land use limits remain in place across the site.

Community members can follow site progress through EPA's online document system, which includes 45 key documents, 67 decision documents, and 7 five-year review reports. Public information repositories are maintained by the Air Force for the Otis program and by the Army for the Camp Edwards program. The most recent five-year review was completed in September 2023, with the next expected between September and November 2028. For direct questions, residents can contact the EPA's Community Involvement Coordinator.