Unconsolidated unsaturated loess overlying bedrock
The top of the bedrock occurs between 3.9 to 5.5 meters below ground surface and consists of inter bedded claystones, siltstones, and sandstones.
Beneath the dry well sourse area, the bedrock is moderately to highly weathered to approximately 14.6 m bgs. The sandstones in the weathered zone are generallyloose to poorly consolidated and more permeable then the interbedded claystones. The sandstones have been interpreted to be the primary pathways of ground-water flow and contaminant transport. Hydraulic conductivities are 6x10-5 cm/sec and ground-water flow is 3-12 m/yr.
Targeted Environmental Media:
 Fractured Bedrock
Major Contaminants and Maximum Concentrations:
- Methylene chloride (2,500,000 µg/L)
- Tetrachloroethene (300 µg/L)
- Trichloroethene (300 µg/L)
- Tracer (dye) Test
Comments:
Pumping tests
- Fracturing
- Bioremediation (In Situ)
Comments:
Application of an enhanced aerobic biological injection process utalizing hydrofracturing to address the low transport rates in a fractured claystone combined with the injection of dissolved methane to stimulate the production of the mono-oxygenase enzyme was implemented in 2002. The full-scale system consists of 40 nested shallow and deep injections spaced throughout a 20 acre area within the 100 ug/L and greater 1,1-DCE plume area. Methane, oxygen, and nutrients have been injected simultaneously over a two year period.
None provided
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