Jump to main content.

Local Navigation

Record of Decision System (RODS)



City & State:  WARMINSTER TOWNSHIP  PA  18974
County:  BUCKS
EPA ID:  PA6170024545
EPA Region:  03
NPL Status:  Currently on the Final NPL
ROD Type:  Record of Decision
ROD ID:  EPA/ROD/R03-93/175
ROD Date:  09/29/1993
Operable Unit(s):  01
Media:  GW
Contaminant:  VOC, Metals
Abstract:  The 734-acre USN Naval Air Development Center (Operable Unit 1) site is a Naval facility located in Warminster and Ivyland, Bucks County, Pennsylvania. Land use in the area is predominantly commercial, industrial, recreational, and residential, with areas of open land, woodlands, and wetlands habitats within and near the site. In addition, the site lies in an upland area between two local drainage basins. The northern 65 percent of the site drains to the north towards Little Neshaminy Creek. The southern 35 percent of the site drains to the south towards the headwaters of Southampton Creek, a tributary of Pennypack Creek. These streams are used for recreational and industrial purposes. The estimated 2,000 people who work onsite use the ground water to obtain their drinking water supply and for industrial and commercial uses. In 1944, the site was commissioned mainly for research, development, testing, and evaluation of Naval aircraft systems. Historically, wastes containing hazardous substances have beengenerated during aircraft maintenance and repair, pest control, fire- fighting training, machine and plating shop operations, spray painting, and various materials research and testing activities in onsite laboratories. From 1940 to 1980, the wastes, including paints, solvents, sludges, and waste oils, were disposed of in onsite pits, trenches, and landfills. In addition, wastes were burned in a fire training area until 1988. These disposal activities resulted in the release of hazardous substances to the environment. To date, eight areas, numbered one through eight, have been identified as areas used for the disposal of wastes containing hazardous substances. None of these areas are currently active. For investigative purposes, sites 1, 2, and 3 have been grouped into area A, while sites 5, 6, and 7 have been grouped into area B. Prior to 1985, EPA conducted two preliminary onsite investigations. Beginning in 1988, the Navy conducted detailed investigations of the site, which indicated that ground water underlying the site was impacted by the past disposal activities. In 1990, the Navy and EPA signed an IAG to establish a procedural framework for developing and implementing onsite investigative and response actions. In 1993, in response to the detection of contamination offsite, the Navy installed water treatment systems in each affected residence. For remediation purposes, the site has been divided into two OUs. This ROD addresses contaminated ground water attributable to areas A and B in overburden and shallow bedrock as an interim remedial action to prevent further migration of contaminated ground water, as OU1. Future RODs will present the final selected remedy for OU1 and will address ground water remedies for contamination in overburden and shallow bedrock in other areas and ground water deep bedrock, waste, soil, surface water, and sediment, as necessary. The primary contaminants of concern affecting the ground water are VOCs, including PCE, TCE and carbon tetrachloride; and metals, including arsenic. SELECTED REMEDIAL ACTION: The selected interim remedial action for this site includes installing ground water extraction wells and pumping ground water to hydraulically control migration of contaminated ground water; treating extracted ground water using air stripping, carbon adsorption, precipitation, sedimentation, and filtration; providing for the potential use of another treatment technology, such as ultraviolet oxidation, if the treatability study indicates that the selected remedy is ineffective for the removal of contaminants; sampling treated water periodically to determine the effectiveness of the treatment system; discharging treated water to an unnamed tributary of either Little Neshaminy Creek or Southampton Creek; installing and operating a vapor phase carbon adsorption unit, as necessary, to remove VOCs from the air stripper emissions; treating or disposing of solid residuals offsite; monitoring ground water in onsite monitoring and residential wells; evaluating, periodically, the hydrogeologic data and the effectiveness of the extraction system in minimizing contaminated ground water migration; and modifying the system, as necessary, based on the periodic evaluations. The estimated present worth cost for this remedial action is $13,172,000, which includesan annual O&M cost of $628,000. PERFORMANCE STANDARDS OR GOALS: Chemical- specific cleanup standards for this interim remedial action were not provided because the goal of the remedy is to limit migration. Treated ground water will meet the effluent limits developed in accordance with the CWA and the State NPDES requirements. INSTITUTIONAL CONTROLS: Not applicable.
Remedy:  The selected interim remedy for OU-1 is the first remedial action addressing the Site. OU-1 consists of contaminated groundwater attributable to Area A and Area B at the Site in overburden and shallow bedrock aquifers. The objective of the selected interim remedy is to minimize the migration of the contaminated groundwater. A final remedial action for OU-1 will be selected in a final Record of Decision for OU-1 to be issued after the full nature and extent of contaminated groundwater attributable to Area A and Area B in overburden and shallow bedrock aquifers are identified. The selection of the final remedial action will consider the information generated during the implementation of the interim remedial action. Future actions at the Site will address groundwater in overburden and shallow bedrock in other areas, groundwater in deep bedrock, waste, soils, surface water, and sediment as necessary.

The selected interim remedy for OU-1 includes the following major components:
* Installation, operation and maintenance of groundwater extraction wells
* Installation, operation and maintenance of an onsite groundwater treatment system which includes precipitation, filtration, air stripping and carbon adsorption, and/or other necessary means of treatment
* Periodic sampling of treated water to ensure the effectiveness of the treatment system
* Discharge of treated water to an unnamed tributary of Little Neshaminy Creek or an unnamed tributary of Southampton Creek
* Installation, operation and maintenance of vapor phase carbon adsorption units as necessary
* Offsite treatment and/or disposal of solid residuals generated during water treatment รน Monitoring of groundwater in monitoring wells and residential wells
* Installation and periodic sampling of observation wells to ensure the effectiveness of the groundwater extraction wells
* Periodic evaluation of hydrogeologic data and the effectiveness of the groundwater extraction wells
* Modification of the groundwater extraction well system and/or groundwater treatment system as necessary based on periodic evaluations
Text:  View full-text ROD [ 61K ]
To download a full-text ROD, right click on the above link and select Save Link As. A full-text ROD is in PDF format. Please note that download time may be extended given the size of the full-text document. File size is noted in kilobytes (K) or megabytes (M) next to the download link.
About Adobe Portable Document Format
Return to Search Results    Return to RODS List

OSWER Home | Superfund Home

Jump to main content.