Site Name: PEASE AIR FORCE BASE
EPA ID: NH7570024847 EPA Region: 01 Metro Statistical Area: 6450
509 CSG/CC, PORTSMOUTH, NH 03803-5000
Operable Unit: 05
ROD ID: EPA/ROD/R01-95/111 ROD Date: 06/26/95
Contaminant: polynuclear aromatic hydrocarbons, halogenated hydrocarbons, semivolatile organic compounds, pesticides, benzoic acid, aromatic hydrocarbons, oxygenated hydrocarbons, metals, phthalates, phenols, diesel fuel, benzoic acid
Keys: groundwater, landfill, solid waste, deed restrictions, long-term monitoring, SVOCs, VOCs, PAHs
Abstract:
Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.
Pease Air Force Base (AFB) is a National Priorities List (NPL) site consisting of numerous areas of contamination. This ROD addresses sources of contamination in Zone 1. Zone 1 comprises Landfill 2 (Site 2 or LF-2), Landfill 3 (Site 3 or LF- Storage Area (Site 13 or BFSA), the Paint Can Disposal Area (Site 44 or PDCA), and the Railroad Tracks Herbicides (Site 46). However, only LF-2, LF-4, the PCDA, and Zone 1 groundwater are addressed in this ROD. Zone 1 occupies approximately 350 acres on the northeastern margin of the former Pease AFB.
Pease AFB is located in the Town of Newington and the City of Portsmouth. Pease AFB occupies approximately 4,365 acres. The base is located on a peninsula in southeastern New Hampshire bounded on the west and southwest by Great Bay, on the northwest by Little Bay, and on the north and northeast by the Piscataqua River. The base is situated near the center of the peninsula.
At the beginning of World War II, an airport at the present Pease AFB location was used by the US Navy. The Air Force assumed control of the site in 1951, and construction of the facility was completed in 1956. Various quantities of fuels oils, solvents, lubricants, and protective coatings were used at the base over time, and releases of contaminants into the environment occurred.
In December 1988, Pease AFB was selected to be closed on March 31, 1991. The New Hampshire Air National Guard (NHANG) remains at the airfield and uses some of the existing facilities. The remainder of the base has been divided among the Department of the Interior, the State of New Hampshire's Pease Development Authority (PDA), and the Air Force.
Although the ultimate disposition/future use of the property has yet to be determined by the PDA, some assumptions have been made concerning future use scenarios for sites in Zone 1. The landfills are considered to have restricted future use potential; construction of residences will not occur on the landfills Construction of residences could, however, occur adjacent to identified source of fill areas. Roads, parking lots, and open space are typical future uses that are reasonable for landfills. The PDCA is located in the NHANG restricted-access area. It is assumed that this area will continue to have restricted access in the future.
Land use in the vicinity of Zone 1 varies. An off base commercial and residential area is located along Spaulding Turnpike, approximately 1,000 feet northeast of the Pease AFB eastern boundary and approximately 500 feet north of the northern boundary of Zone 1. The North Ramp is adjacent to Zone 1 in the west.
Historic land use in Zone 1 included waste disposal at LF-2, LF-4, LF-5, and the PCDA. Fuel storage and transfer occurred at the BFSA.
Remedy:
The selected remedy at Zone 1 addresses the principal threat posed by the migration of contaminated groundwater from the LF-5 source area. Implementation of this remedy will prevent endangerment of public health, welfare, and the environment by allowing natural physical and chemical attenuation processes to remove residual contamination in groundwater.
The selected remedy also involves the placement of deed restrictions on the use of groundwater in areas of Zone 1 where Maximum Contaminant Levels (MCLs) are exceeded for the time period during which the MCLs are exceeded and long-term environmental monitoring in the zone. In addition, a Groundwater Management Zone (GMZ) will be established in accordance with New Hampshire Department of Environmental Services (NHDES). A GMZ is the designation used by NHDES to denote a subsurface volume in which groundwater contamination associated with the discharge of a regulated contaminant is contained and managed. The use of the contaminated groundwater is managed typically through institutional controls such as deed restrictions, and groundwater is monitored in the GMZ.
No further action under CERCLA is planned for LF-2, LF-4, and the PCDA. These sites will be closed according to applicable New Hampshire regulations. LF-5 and the Railway Ditch are addressed in a separate ROD. Removal of waste materials from the PCDA was performed. LF-3 has been addressed in a No Further Action Decision Document. The Railroad Tracks also have been recommended for no further action. In addition, the BFSA is not addressed in the selected remedy for the zone because the site has been excluded from the amended Federal Facilities
Agreement.
Operable Unit: 10
ROD ID: EPA/ROD/R01-95/103 ROD Date: 08/09/95
Contaminant: total petroleum hydrocarbons(TPHs), trichloroethylene(TCE), tetrachloroethene(PCE), chlorobenzene, benzene, toluene, ethylbenzene, xylenes, polynuclear aromatic hydrocarbons (PAHs), arsenic, cadmium, calcium, chromium, copper, lead, magnesium, nickel, silver, thallium, zinc, vinyl chloride, cis-1,2
Keys: soil, groundwater, VOCs, TPHs, TCE, PCE, PAH, arsenic, lead, in situ, air sparging, extraction, soil vapor extraction, excavation, off-site, disposal, land use restrictions, long-term monitoring, GMZ, storage tanks, fence, well
Abstract:
Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.
Pease Air Force Base (AFB) is located on a peninsula in southeastern New Hampshire. The peninsula is bounded on the west and southwest by Great Bay, on the northwest by Little Bay, and on the north and northeast by the Piscataqua River. The City of Portsmouth is located east and southeast of the base. Pease AFB occupies 4,365 acres and is located approximately in the center of the peninsula.
The Old Jet Engine Test Stand (OJETS) occupies an area of approximately six-tent of the runway and 400 feet north of the Golf Course Maintenance Area (GCMA).
At the beginning of WWII, the U.S. Navy used an airport located at the present Pease AFB. The Air Force assumed control of the site in 1951, and construction of the existing facility was completed in 1956. During its history, Pease AFB was the home of the 100th and 509th Bombardment Wings, whose mission was to maintain a combat-ready force capable of long-range bombardment operations. The New Hampshire Air National Guard (NHANG) relocated in the 157th Military Airlift Group from Grenier Field in Manchester, New Hampshire, to Pease AFB in 1966. The mission of the group was changed in 1975, when it was designated as the 157th Air Refueling group. Over time, various quantities of fuels, oils, solvents, lubricants, and protective coatings were used at the base for routine maintenance operations, and releases of contaminants into the environment occurred as a result of usage and disposal of these and other materials.
Land use in the vicinity of the OJETS is limited to the runway, which is approximately 1,000 feet to the northeast; the GCMA, which is 400 feet to the south; Lowry Lane, which runs along the east side; and an open field and wooded area, which are to the west of the OJETS. A fence runs along the eastern edge of the site and separates the OJETS from the flightline area.
There are approximately 3,700 dwellings within a one-mile radius of Pease AFB. Based on water usage surveys conducted in 1988 and 1992 and on available U.S. Geological Survey (USGS) and New Hampshire Department of Environmental Services (NHDES) information, a number of these dwellings have wells and/or springs located on their properties. The OJETS is relatively isolated from the off-base residential areas. The closest dwelling downgradient of the OJETS that has a well or spring is approximately 3,500 feet away.
Surface water runoff from the OJETS is minimal because the site is relatively flat and the soils are highly permeable. All rainfall and snowmelt at the OJETS infiltrates into the subsurface at, or immediately downgradient of, the site. There is no surface water body that receives runoff from the OJETS.
The OJETS was constructed in approximately 1958 and consisted of a partially enclosed engine test stand (roof and sidewalls), an engine control room structure adjacent to the test stand, a fuel storage tank, associated pumps and piping, and a rock-filled, in-ground crib. During testing, engine exhaust was directed out of the northern end of the containment structure toward the rock crib, which was designated to deflect the exhaust from engines being tested. Between 1965 and 1976, the perimeter of the rock crib was paved with asphalt.
The test stand was used heavily, particularly in the mid-1960s when the base had its minimum number of aircraft. Records related to the detailed operation of the test stand are not available; however, extensive use of petroleum products, hydraulic fluids, and solvents likely occurred at the OJETS. After the OJETS was removed from service in 1976, and prior to commencement of the Site Inspection (SI) in 1992, the engine control room, aboveground fuel storage tank, and transformer were removed from the site. As part of the Remedial Investigation (RI) the OJETS building, cement pad, and rock crib were removed in 1993.
Remedy:
The selected remedy involves in situ air sparging treatment of contaminated soil below the water table; in situ vapor extraction treatment of contaminated vadose zone soil; and installation of a low-permeability membrane on the ground surface in the source area. In addition, delineation, and if necessary, excavation and off-site disposal of surface soils contaminated above cleanup goals for inorganics will be conducted. Following remediation of the contaminated soil (the source of groundwater contamination), natural physical and chemical attenuation processes will remove residual contamination in groundwater.
The selected remedy also involves the placement of land use restrictions on the use of groundwater in the vicinity of the OJETS where MCLs are exceeded for the time period during which MCLs are exceeded, and long-term environmental monitoring at the site. In addition, a Groundwater Management Zone (GMZ) will be established. A GMZ denotes a subsurface volume in which groundwater contamination associated with a discharge of a regulated contaminant is contained and managed.
Operable Unit: 06
ROD ID: EPA/ROD/R01-95/110 ROD Date: 09/18/95
Contaminant: total petroleum hydrocarbons, dioxins, lead, benzene, toluene, ethyl benzene, xylenes, aromatic hydrocarbons, halogenated hydrocarbons, arsenic, manganese, napthalene, ethylene dibromide, BTEX, acetone, diethyl ether, trichlorofluoromethane, trichloroethane, benzoic acid, pesticides, PCBs, calcium, tetrachloroethene, mercury, thallium, chlorobenzene, methyl isobutyl ketone
Keys: soil, groundwater, surface water, LNAPL, soil vapor extraction, air sparging, VOCs, institutional controls, GMZ, monitoring, surface water, sediment, leachate, wells, SVOCs, TPH, AHC, EDB, PCE, TCE, lead, BETX, pesticides, mercury
Abstract:
Please note that the text in this document summarizes the Record of Decision for the purposes of facilitating searching and retrieving key text on the ROD. It is not the officially approved abstract drafted by the EPA Regional offices. Once EPA Headquarters receives the official abstract, this text will be replaced.
Pease Air Force Base (AFB), Zone 2 site, is located in the Towns of Newington and Greenland, and in the City of Portsmouth, New Hampshire. Pease AFB is located on a peninsula bounded on the west and southwest by Great Bay, on the northwest by Little Bay, and on the north and northeast by the Piscataqua
River. Pease AFB occupies 4,365 acres and is located in the center of the peninsula. The City of Portsmouth is located approximately three miles from the base.
During the history of the land occupied by Pease AFB, various quantities of fuels, oils, solvents, lubricants, and protective coatings were used at the base and releases of contaminants into the environment occurred as a result of usage and disposal of these and other materials.
All Air Force activity within Zone 2 was halted when the base officially closed. Land uses at the base since closure include industrial, commercial, and military. Stewardship of the area west of McIntyre Road has been granted to the U.S. Fish and Wildlife Service, and the area is operated as part of the Great Bay National Wildlife Refuge. This area is largely wooded, and contains Upper and Lower Peverly Ponds and Bass Pond. Between McIntyre Road and the runway to the east are two former burn areas, a former fire training area, and an area formerly used for sludge disposal.
There are approximately 3,700 dwellings within a one-mile radius of the site. It has been determined that a number of these dwellings have wells and/or springs located on their associated properties. The Town of Newington, in particular, had a large number of private wells. The closest dwelling to Zone 2 that has a well or spring is only 2,000 feet away.
Based on the data collected during the remedial investigation, it was shown that soil and groundwater have been affected by past disposal practices at Zone 2. Chemicals of concern remaining in the unsaturated soil are primarily total petroleum hydrocarbons (TPHs), and dioxins and lead at concentrations above background. Saturated soil areas have significant residual contamination, including benzene, toluene, ethylbenzene, and xylenes (BTEX)
and TPHs.
Groundwater contamination consists mainly of BTEX, aromatic hydrocarbons (AHCs), low levels of halogenated hydrocarbons (HHCs), and metals, including: arsenic, manganese, and lead. Other groundwater contaminants exceeding Maximum Contaminant Levels (MCLs) include: benzene, etyhlbenzene, toluene, and napthalene, ethyl dibromide.
Surface water does not appear to have been impacted by past practices in Zone 2. Sediment samples contain pesticides and metals above background levels. The pesticides are the result of basewide pesticides and metals above background levels; they are not the result of spillage or disposal of pesticides in Zone 2.
Remedy:
This action addresses the principal threat posed by leaching of contaminants to groundwater at BA-1 and the associated groundwater contaminant plumes.
The selected remedy includes in-situ treatment of BA-1 source area light, nonaqueous phase liquids (LNAPLs) and residual LNAPL with enhancement of soil vapor extraction (SVE) by air sparging, which involves injection of air below the water table. Extracted soil vapor will be treated for removal of volatile organic compounds (VOCs). The remedy selected for BA-1 addresses the groundwater plumes associated with zonewide groundwater contamination. The selected remedy also includes establishment of institutional controls restricting future use of Zone 2 groundwater, including a Groundwater Management Zone (GMZ) and performance of long-term monitoring. The selected remedy for Zone 2 also includes natural attenuation of groundwater contamination. As part of the selected remedy for BA-1, surface water, sediment, and fish tissue sampling will be conducted at the Peverly Ponds and Bass Pond, although BA-1 is not considered a source of surface water and sediment contamination. The reuse for the portion of Zone 2 located east of McIntyre Road will be under the jurisdiction of the Pease Development Authority (PDA) to support airport operations. Reuse of the portion of Zone 2 west of McIntyre Road will be under the jurisdiction of the U.S. Fish and Wildlife Service to support a National Wildlife Refuge.