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: January 2, 2011

Point of Contact:
Joshua Barber
USEPA 1650 Arch Street
Mail Code: 3HS21
Philadelphia PA 19103 
Tel: 215-814-3393 
Email: barber.joshua@
pa.mail

Tysons Dump
Merion, PA


Hydrogeology:

Three types of geologic materials were encountered during the remedial investigation (RI): the overburden materials south of the railroad tracks, the floodplain deposits north of the railroad tracks, and the lower member of the Stockton Formation which underlies all of the unconsolidated materials within the area of the investigation. The overburden materials south of the railroad tracks can be divided into three types of materials: undisturbed colluvial deposits, fill material emplaced during past remedial activities at the former lagoon areas, and construction debris and fill material in the seep area.

The lower member of the Stockton Formation beneath the site can be divided into four lithologic units, each of which is highly variable in thickness. these units, from shallowest to deepest, include:
* brownish-red arkosic sandstone, dark to light brownish-red, medium to coarse grained, arkosic sandstone, with trace biotite and quartz cobbles; the average thickness is twenty feet.
* light grey green arkosic sandstone, light grey-green arkosic sandstone with some dark green fine to medium grained arkosic sandstone, with trace to little biotite and trace olive green medium grained arkosic sandstone; the
average thickness is seventy-five feet.
* red shale, dark red silty shale with a trace biotite, typically five to ten feet thick.
* dark green arkosic sandstone, dark green fine to medium grained arkosic-subarkosic sandstone, trace biotite, little to some light grey green medium to coarse grained sandstone, trace tiotite. this basal unit was found to be
at least forty feet thick.

Groundwater at the site occurs in two principal flow systems: a local system in the unconsolidated deposits overlying the bedrock and a regional system in the fractures, joints and bedding planes of the underlying bedrock.

Both primary and secondary permeability are apparent in all three zones monitored in the bedrock aquifer. Secondary permeability is contributed by discontinuities such as joints, fractures, faults, and weathered bedding planes. The occurrence of significant zones of enhanced secondary permeability is represented by the fracture traces. The fracture traces are indicative of vertical planes of fracture concentration.

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

Contaminants:

DNAPLs have been physically observed at depths of 600 feet bgs and 1,500 feet away from the source lagoons. Contaminated groundwater has been found at 1,000 feet bgs.

Major Contaminants and Maximum Concentrations:
  • - 1,2,3-Trichloropropane (1,200,000 µg/L)
  • - Xylenes (Not given)
  • - Toluene (Not given)
  • - cis-1,3-Dichloropropene (Not given)
  • - Tetrachloroethene (Not given)
  • - Trichloroethene (Not given)

Site Characterization Technologies:

No technologies selected.


Remedial Technologies:

  • - Pump and Treat
Comments:
The initial pump and treat system (seven extraction wells)for the bedrock aquifer became operational in 1990. This system was designed to prevent contamination from entering the Schuylkill River. Six additional wells were added to this system in 1991. In the mid 1990s two additional deep recovery wells became operational. As of 2004 there are 14 pumping wells.

Over 200,000 pounds of VOCs have been removed by SVE from overburden soils.
Remediation Goals:

TABLE 2
TYSON'S SITE
ACCEPTABLE LEVELS IN GROUND WATER
CHRONIC WATER
COMPOUND EXPOSURE, MG/L ORAL
ANILINE 6/1E-03
ANTHRACENE 7.00E + 00
BENZENE 2.20E - 04
BENZOIC ACID 7.00E - 01
BIS(2-ETHYLHEXYL)
PHTHALATE 2.5E-03
2-BUTANONE 1.80E + 00
CHLOROBENZENE 6.00E - 02
2-CHLORONAPHTHALENE 1.10E - 01
2-CHLOROPHENOL 1.00E - 01
CHRYSENE 1.50E - 06
CYCLOHEPTATRIENE 2.00E - 02
CYCLOHEXANONE 2.30E - 01
DI-N-BUTYL
PHTHALATE 3.50E - 00
DI-OCTYL PHTHALATE 6.30E - 01
DICHLOROBENZENES * * * *
2,4-DIMETHYLPHENOL 2.80E - 01
N,N-DIMETHYL-L,3-
PROPANEDIAMINE 6.50E - 01
DODECANE 3.90E + 00
ETHYLBENZENE 6.80E - 01
1-ETHYL-2-
METHYLBENZENE 1.20E - 01
FLUORANTHENE 2,10E - 01
HEXADECANE 2.20E + 01
HEXADECANOIC ACID 2.00E - 02
METHYLENECHLORIDE 1.60E - 03
2-METHYLNAPHTHALENE 5.30E - O1
2-METHYLPHENOL/
4-METHYL PHENOL 1.80E + 00
4-METHYL-2-
PENTANONE 1.80E + 00
N-NITROSO
DIPHENYLAMINE 7.10E - 03
NAPHTHALENE 1.4E-01
NITROBENZENE 1.80E - 02
1,1-OXYBIS-
(2-ETHOXYETHANE) 8.50E - 01
PHENANTHRENE 2.50E - 01
PHENOL 1.4E+00
PYRENE 3.8E-05
TERTRACHLOROETHENE 2.30E - 04
TETRAMETHYLUREA 7.60E - 01
TOLUENE 2.00E + 00
1.2,4-TRICHLORO
BENZENE 2.30E - 01
1,3,5-TRICHLORO
BENZENE 2.30E - 01
TRICHLOROETHENE 1.10E - 03
1,2,3-TRICHLORO
PROPANE 3.50E - 04
TRIDECANE 4.10E - 01
UNDECANE 1.80E - 01
O-XYLENE 1.20E - 01
* 1,2 DICHLOROBENZENE 3.1E+00
* 1,3 DICHLOROBENZENE 3.1E+00
* 1,4 DICHLOROBENZENE 1.


Status:

The groundwater recovery system remains operational and dissolved contaminant concentrations are decreasing. However, given the amount of DNAPL present and primary porosity in the bedrock rebound will occur. The discharge of DNAPL and dissolved phase chemicals to the Schuylkill River has stopped.

http://cfpub.epa.gov/supercpad/cursites/csitinfo.cfm?id=0301436

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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