Contaminants in groundwater near North Penn Area Superfund sites

Science Center Objects

USGS has investigated groundwater flow and contaminant transport in the vicinity of Superfund sites in Montgomery County, southeastern Pennsylvania, in cooperation with EPA. Additional cooperative support for these investigations has been provided by the Pennsylvania Department of Environmental Protection, Montgomery County, and local government agencies.

Highlights

  • Industrial solvent contaminants have migrated in fractured-rock aquifers in the vicinity of North Penn Area Superfund sites
  • Newark Basin aquifers of the Brunswick Group and the Lockatong Formation 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
  • Groundwater-flow models were developed based on synthesis of field-test results using a 3D hydrogeologic framework of dipping mudstone and shale strata
  • Simulations of transport paths were compared to observed contaminant distributions, and the simulated effect of changes in pumping on flow paths helped optimize pump and treat system operation
  • Areas contributing recharge to streams and discharging wells were mapped using the groundwater-flow models; as groundwater withdrawals in the area have decreased, a higher proportion of local recharge ultimately discharges to streams

Non-publication abstracts and presentations. (see Publications for reports and articles)

  • Streamflow Depletion by Groundwater Pumping from Fractured-Rock Aquifers of the Newark Basin: 2014 Pennsylvania Groundwater Symposium (ARCHIVED abstract)
  • Comparison of Stair-Step and Dipping-Layer Approaches for Simulation of Flow and Advective Transport in Fractured-Sedimentary Formations: 2007 National Ground Water Association / EPA Fractured Rock Conference (ARCHIVED abstract)
  • Scale and Hydrogeologic Complexity in Models of Ground-Water Flow for Newark-Basin Aquifers: Rutgers University 2004 Regional Workshop on Hydrogeology of the Newark Basin (ARCHIVED abstract & presentation)