Summary
Pease Air Force Base (Pease AFB) is located in the New Hampshire Seacoast Region between the City of Portsmouth and the towns of Newington and Greenland, New Hampshire. From 1956 until its closure in 1991, the base maintained a combat-ready force for long range bombardment operations. Due to environmental contamination of soils and groundwater, Pease AFB was placed on the National Priorities List in 1990.
Under the Air Force’s Installation Restoration Program, environmental investigations began in 1983. Currently, the base is in the later stages of cleanup, with Records of Decision completed for contaminated areas and all required remedial actions complete or ongoing. Base property is being transferred to the Pease Development Authority for reuse as a civilian commercial center.
The New Hampshire Department of Health and Human Services (NHDHHS) and the U.S. Agency for Toxic Substances and Disease Registry (ATSDR) have reviewed available environmental information related to contaminated areas on the base and identified several exposure situations requiring more detailed evaluation. The situations involved past and current exposures to chemical contamination in surface water, groundwater, sediments, and fish tissue. NHDHHS also reviewed soil gas data to evaluate the possibility that groundwater contamination beneath the base might affect the indoor air quality of some buildings on the site.
Based on this review, all of the exposure situations were categorized as either no apparent public health hazard or no public health hazard due to chemical exposures at levels that are unlikely to result in adverse health effects, or limited access to chemical contamination that prevents exposure
Exposure Situations With No Apparent Public Health Hazard
Consumption of contaminated groundwater
Past use and disposal of chemicals on the base have resulted in groundwater contamination. In 1977, trichloroethylene (TCE) was detected in the base water supply aquifers. In 1994, nitrate concentrations in the base drinking water supply were elevated. Both contaminants were at levels exceeding current drinking water standards. Although levels were above regulatory drinking water standards, people exposed to these contaminants in drinking water are unlikely to experience any adverse health effects because of the low levels of chemicals present and short duration of exposure. The contamination sources have been identified and measures taken to reduce the contaminant levels. Drinking water on base is regularly monitored, and currently meets all standards for drinking water.
Recreational Use of Peverly and Bass Ponds
Chemical contamination was found in sediments, surface waters, and fish in Peverly and Bass Ponds. These ponds were used for fishing and swimming while the base was active. Exposures to mercury, polychlorinated biphenyls (PCBs), and the pesticide DDT by past recreational users who swam, waded, and fished were below levels where adverse health effects are likely. Currently, the area is within the Great Bay National Wildlife Refuge and access is restricted.
Exposure Situations with No Public Health Hazard
Installation Restoration Program sites
The 49 Installation Restoration Program (IRP) sites, flight line, and petroleum underground storage tanks pose no public health hazard. There is no evidence of past or current exposures to hazardous substances at these sites and future exposures are not likely to occur. Institutional controls such as restrictions on use of groundwater and limitations on construction in contaminated areas are in place to prevent exposure. Contamination is under remediation, and the migration of contaminants in the environment is being monitored and is not expected to result in future exposures for workers and visitors at Pease AFB.
Potential Exposure Situations
Potential Building Indoor Air Contamination
It is theoretically possible that some contaminants in the groundwater beneath Pease AFB may evaporate, migrate upwards through the soil gas, and eventually impact the indoor air quality of buildings in the area. While there are no data on indoor air quality at Pease AFB, limited data on soil gas do not suggest that current indoor air quality problems would be expected. However, to guard against potential future exposures, this potential pathway should be kept in mind during the redevelopment of the base.