The Defense Fuel Support Point - Newington (DFSP) (FFID - NH197152484700) is located approximately 4 miles northwest of Portsmouth, New Hampshire and 2 miles northeast of Newington. The terminal is 14.9 acres and lies on the Piscataqua River, which is a major waterway used for the shipping of manufactured products. The DFSP mission was to receive, store, and deliver jet propulsion fuel (JP-4) and employed 1 military and 11 civilians before closing in February 1990. The US Air Force currently owns the property.
The DFSP has a docking pier for unloading fuel from barges and tankers, and a truck loading rack. Aviation Gas and then jet propulsion fuel were stored in two 80,000 barrel and four 50,000 barrel underground storage tanks at this facility. All of the tanks, which are below ground, are constructed of steel and have a 12-inch concrete and 4-foot soil cap. During cleaning operations in April 1981, an explosion at Tank 3 destroyed the top of the tank, which remains out-of-service. Prior to the closure of Pease Air Force Base, the terminal pumped JP-4 to Pease Air Force Base through 8- and 10-inch pipelines that are approximately 1-1/4 miles in length. The DFSP supplied fuel to New Hampshire State Military Reservation, Concord, and Fort Devens, Massachusetts by tank truck. All of the tanks and the pipeline have been drained and cleaned and are currently inactive.
Since 1983, twelve site assessment subsurface studies were conducted at the site and off-site. Five major contaminated areas were identified at the site. Remedial efforts began in 1984 with free-phase floating product recovery, and has progressed to an integrated effort combining soil vapor extraction treatment, groundwater extraction and soil removal.
The groundwater contamination problems at DFSP have occurred at the manifold (the piping and valve system to route the fuel between the delivery pier, storage tanks, Pease Air Force Base and the truck filling station), the stormwater lagoon, two underground oil/water separator tanks and the truck filling station, commonly called the truck rack. Some valves and comparison flanges at the manifold had leaked directly onto the ground for an undetermined period of time. Fuels that did not evaporate infiltrated into the upper soil horizon and percolated to the shallow aquifer. A concrete pad for containing leaking fuel and runoff was installed in the fall of 1982 and was removed in 1996 to facilitate the removal of soils in the manifold area.
One of the underground oil/water separator tanks (OWS2) was located directly adjacent to the manifold area and was designed to receive runoff from the manifold area concrete pad. This tank over-flowed on February 3, 1983. The investigation of this overflow included excavating around OWS2 which revealed a broken 4-inch cast iron inlet pipe and an appreciable quantity of fuel in the ground near the top of the tank. Approximately 2,500 gallons of fuel were recovered from the excavation. The tank and all lines feeding it were removed in 1991. Investigations at the monitoring wells in the area of the manifold and OWS2 (manifold area) indicated that a recoverable quantity of fuel existed in the subsurface. There was no evidence to show that fuel found in the subsurface migrated from the area to the Piscataqua River.
From April of 1984 to June of 1986 a total of 1,154 gallons of product were recovered from the manifold area with a fuel recovery trench and well. Additional active remediation was conducted at the manifold area, starting in January of 1992, where approximately 4,300 pounds of petroleum hydrocarbons were removed from the subsurface soil by multi-point dewatering/treatment and SVE. All identified free-phase floating product was recovered. Subsequent routine monitoring showed that there was another occurrence of floating fuel products in the subsurface. As a result the Remedial Action Plan was revised to provide for removing contaminated soils from all contaminated areas on the site, including the truck rack, OWS1 and the manifold area.
In October of 1996 approximately 500 tons of soil was removed from the site and transported for thermal treatment. Subsequent analyses showed that the removal successfully lowered contaminants in the truck rack and the OWS1 areas. The manifold area still showed some contamination, including increased levels of benzene, ethylbenzene and naphthalene in some monitoring wells downgradient of the soil excavation. Subsequent analyses showed that ethylbenzene decreased below the AGQS levels, while benzene and naphthalene have been typically decreasing. Accordingly, the Department issued a Certificate of Completion in October of 1997 stating that the active remediation is complete.
The groundwater quality at the site has been managed via groundwater monitoring networks consisting of up to 19 monitoring wells. A Groundwater Management Permit (GMP) was issued in 1995, and reissued in 2000. This GMP currently requires monitoring of the groundwater at seven monitoring wells.