Contaminants in groundwater near former Navy bases in southeastern Pennsylvania

Highlights

• The latest report (see Publications) describes results of packer tests and other vertical profiling methods in 15 boreholes in fractured sedimentary bedrock in Northampton, Warminster, and Warwick Townships.
• Regional groundwater-flow paths from possible PFAS source locations at and near Willow Grove and Warminster bases terminate at streams and pumping wells with a few miles of the bases.
• Industrial chemical contaminants have migrated in fractured-rock aquifers in the vicinity of former Navy bases.
• Newark Basin aquifers of the Brunswick Group and the Lockatong and Stockton Formations have been used for industrial and drinking-water supply.
• Field testing characterized the highly heterogeneous and anisotropic strata showing the predominant role of bed-oriented fractures in contaminant migration.
• Measured water levels in wells were used to construct water-level maps, and aquifer testing revealed high-permeability hydraulic connections between wells.

Recent & Ongoing Studies

• USGS is conducting borehole geophysical and packer testing to help characterize the area hydrogeology and design groundwater monitoring systems.
• Groundwater-flow modeling was used to synthesize field-test results using a 3D hydrogeologic framework of dipping shale, mudstone, and sandstone strata.
• Modeling was used to show how changes in pumping over time have changed flow paths from possible contaminant source areas, providing scientific information for characterization, monitoring, and remediation activities.
• Areas contributing recharge to groundwater that then discharges to streams or water-supply wells were mapped using groundwater-flow modeling; as groundwater withdrawals in the area have decreased, a higher proportion of local recharge ultimately discharges to streams.

Streamflow Monitoring

USGS provides streamflow information in the study area that can be used in conjunction with water quality data to evaluate the mass of contaminants transported by streams and the relations between concentrations and flow conditions. Other applications may include evaluating groundwater/surface water interactions and transient effects of point discharges from wastewater treatment plants.

Data Access

• Stream gage data in the study area is Tabulated Here.
• Find these and other surface-water data using the National Water Information System (NWIS) Mapper.

For reports, datasets, and maps collated by location see

• Former Naval Air Station / Joint Reserve Base
• Former Naval Air Warfare Center (NAWC) Warminster