U.S. EPA Contaminated Site Cleanup Information (CLU-IN)


U.S. Environmental Protection Agency
U.S. EPA Technology Innovation and Field Services Division

Fractured Bedrock Project Profiles

Last Updated: February 8, 2011

Point of Contact:
Brad White
USEPA 1650 Arch Street
Mail Code: 3HS22
Philadelphia PA 19103-2029 
Tel: 215-814-3217 
Email: white.brad@
pa.gov

Valmont TCE
West Hazleton, PA


Hydrogeology:

The Site is located in the Appalachian Mountain Section of the Valley and Ridge Physiographic Province. The Appalachian Mountain Section consists of broadly folded Paleozoic sedimentary rocks that range in age from Mississippian to Pennsylvanian. Pennsylvanian age Pottsville Group and the Mississippian age Mauch Chunk formations underlie the Site. The average depth to competent bedrock is about 14 feet bgs.

The Pottsville Group is a terrestrially deposited, fluvially influenced complex composed primarily of gray conglomerate, conglomeritic sandstone, siltstone, sandstone, and some thin beds of anthracite coal. The Mauch Chunk Formation underlies the Pottsville beneath the Site at a depth of less than 300 feet. The Mauch Chunk Formation is composed of an interbedded brownish-gray to grayish-red siltstone, claystone, and brownish-gray to pale red poorly cemented, fine grain sandstone.

The occurrence and migration of groundwater beneath the Site are primarily controlled by open bedrock fractures. Fractures are found both at lithologic contacts (bedding plane fractures) and within lithologic units (cross-bedding fractures). Fractures tend to be more common near the contacts between finer-grained rocks, such as siltstone, shale, and sandstone beds. The predominant orientation of bedding planes based on strike distribution was east-northeast and west-northwest. In general, all porosity information indicated very low matrix porosity in both sandstones and shales. Higher measured porosities are observed in some sandstones, but are more often attributed to secondary porosity associated with fractured rock.
The bedrock aquifer is the primary source of drinking water in the area. Groundwater is also found in localized, perched conditions in the overburden. Depth to water at the Site ranges from 10 feet (near the groundwater divide in the Plant area) to approximately 30 feet below ground surface.

Targeted Environmental Media:
  • - Dense Non-aqueous Phase Liquids (DNAPLs)
  • - Fractured Bedrock

Contaminants:

The plume of VOC contaminated groundwater measures approximately 2,000 feet by 500 feet, to an approximate depth of 110 feet.

Major Contaminants and Maximum Concentrations:
  • - Trichloroethene (17,000 µg/L)
  • - Tetrachloroethene (35 µg/L)
  • - 1,2-Dichloroethene (1,030 µg/L)
  • - 1,1-Dichloroethane (370 µg/L)
  • - 1,1,1-Trichloroethane (13,000 µg/L)
  • - 1,1-Dichloroethene (280 µg/L)

Site Characterization Technologies:

  • - Vertical Chemical Profiling
    • Packer Isolation

Remedial Technologies:

  • - Chemical Oxidation (In Situ)
    • Permanganate
Comments:
A pilot insitu chemical oxidation (ISCO)injection with potassium permanganate was conducted between 2009 and 2010.
Remediation Goals:

MCLs were chosen as cleanup goals.


Status:

The remedy (ISCO) has been selected but the ROD has not been issued.

http://cfpub1.epa.gov/supercpad/cursites/csitinfo.cfm?id=0303307

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For more information on Fractured Bedrock, please contact:

Ed Gilbert
Technology Assessment Branch

PH: (703) 603-8883 | Email: gilbert.edward@epa.gov