The Agency for Toxic Substances and Disease Registry (ATSDR), a public health agency of the U.S. Department of Health and Human Services, today released for public comment a public health assessment addressing contaminants at the
Hanscom Field/Hanscom Air Force Base (HF/HAFB) site in Middlesex County, Mass.

HF/HAFB is a 1,120-acre site located 14 miles northwest of Boston near the towns of Bedford, Concord, Lincoln and Lexington. The site comprises Hanscom Air Force Base (HAFB), an active U.S. Air Force (USAF) base, and L.G. Hanscom Field (HF), an adjacent civilian airport owned by the Commonwealth of Massachusetts and operated by the Massachusetts Port Authority and the Federal Aviation Administration. Light industry, residential areas and open space surround HF/HAFB and the headwaters of the Shawsheen River are on the site.

Throughout its history, routine operations at HAFB generated wastes, including paint waste, chlorinated solvents, fuel, aromatic solvents and polychlorinated biphenyls (PCBs). These wastes were often burned during fire training exercises, buried in landfills or discharged to adjacent wetlands and streams. In addition, the handling and storage of fuels in underground storage tanks and above-ground storage tanks released contaminants to the soil and groundwater.

In the early 1980s, the USAF initiated site investigations under the U.S. Department of Defense's Installation Restoration Program (IRP). The investigations initially identified 13 areas of contaminated soil and groundwater. During subsequent investigations, USAF located a total of 22 potential contaminant source areas.

In May 1994, the U.S. Environmental Protection Agency placed HF/HAFB on the National Priorities List because of contamination found in groundwater and subsurface soil. Using these and other investigation findings, the USAF is conducting ongoing remedial actions to address site contamination and protect public health at eight IRP sites. The other 14 potential contaminant source areas have been closed out with regulatory approval.

In 1994 and again in 2003, ATSDR conducted site visits at HAFB. Although no imminent public health hazards were present at the site, ATSDR did identify three exposure pathways for additional evaluation: (1) potential exposure to site-related contaminants via groundwater, (2) potential contact with contaminants from former landfills, and (3) potential exposure to surface water and sediment.

ATSDR evaluated available environmental sampling data from long-term monitoring and individual IRP site investigations. Overall, HF/HAFB poses no public health hazard. On the basis of its evaluation, ATSDR reached the following conclusions regarding the three exposure pathways:

Groundwater: Volatile organic compounds have been detected in groundwater beneath and immediately downgradient of HF/HAFB. However, this groundwater is not used as a drinking water source. ATSDR has concluded that public and private wells located downgradient of HF/HAFB have not been affected by site-related contamination.

Surface Soil: Most soil contamination areas at HF/HAFB were beneath the surface, thus generally inaccessible to the public. ATSDR evaluated the three areas where surface contamination was possible. Given the limited contamination found in these soils, previous and ongoing remedial actions, and institutional controls in place; no current or future health hazards are associated with these areas. ATSDR finds that past exposure to surface soil contamination is an indeterminate public health hazard.

Surface Water and Sediment: Expected doses from exposure to concentrations of contaminants measured in the Shawsheen River and surrounding wetlands are not likely to have caused adverse health effects. Consequently, no public health hazards are associated with using the Shawsheen River or surrounding wetlands for recreational purposes.

The public health assessment will be available for review and comment through April 12, 2004, at the following repositories:

Base Library
Hanscom AFB
Bldg. 1530
Hanscom AFB, MA 01731

Environmental Flight Office
Hanscom AFB
Bldg. 1810
Hanscom AFB, MA 01731

Comments on the public health assessment must be made in writing. Mail comments to

Chief, Program Evaluation, Records and Information Services Branch
ATSDR
1600 Clifton Road, N.E. (MS E-60)
Atlanta, GA 30333

Comments received during this public comment period will be logged in to ATSDR's administrative record for this health assessment. Comments received, without the names of individuals who submitted them, and ATSDR's responses to the comments will appear in an appendix to the final public health assessment. Names of those who submit comments, however, will be subject to release to requests made under the U.S. Freedom of Information Act.

For more information, community members can contact Environmental Health Scientist Jeffrey Kellam or Community Involvement Specialist Januett Smith-George toll free at 1-888-422-8737. Regional Representative Gary Perlman also may be contacted at 617-918-1492.