Glacial till overlies the heterogeneous, fractured sedimentary bedrock aquifer. The bedrock plume extends about 1,700 feet from the source areas. DNAPL has been observed in nearby wells.
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
Major Contaminants and Maximum Concentrations:
- Chlorobenzene (Not provided)
- Benzene (Not provided)
- Mirex (0 µg/L)
No technologies selected.
- Other (Nanoscale zero-valent iron (NZVI) was used to treat contaminated ground water.)
Comments:
A PRP conducted a multi-phase Remedial Investigation and Feasibility Study (RI/FS) which was being overseen by U.S. EPA and Ohio EPA. The study included installation and seasonal monitoring of a 70-well groundwater and residential monitoring system. To abate the immediate threat to human health and the environment posed by surface water runoff and sediment migration (a major transport mechanism of mirex), a removal AOC was effected November 1993, whereby Rutgers installed a leachate collection and onsite treatment system, numerous sediment barriers and surface water diversion structures.
Bench-scale and field-scale testing were performed to test formulations and effectiveness of NZVI. During the field study conducted in November 2006, 100 kilograms of NZVI in 2,665 gallons of clean water were injected into the aquifer. Powdered soy was used as a dispersant, which accounted for 20 percent by weight, and most batches injected included palladium, which accounted for one percent by weight. Chemical monitoring was conducted for six months. Tetrachloroethene and trichloroethene were reduced by up to 98 and 99 percent respectively. Methane, ethene, and ethane were produced as well as cis-1,2 dichloroethene. Benzene was not degraded during the NZVI treatment, but rather, was produced as a byproduct.
Preliminary results from the field testing were promising. Geochemical and chemical data showed that all of the monitoring wells (located 10 to 20 feet from the injection well) were being influenced. After four weeks there were substantial reductions in all wells of PCE (38 to 88 percent of the initial well concentration)and TCE (30 to 70 percent of the initial well concentration). Non-toxic end breakdown products (methane, ethane, ethane) increased. However, cis-DCE was produced, likely by partial dechlorination of parent compounds.
Not identified in the reference.
Monitoring results of the study will be evaluated during the summer of 2007.
Because of aquifer testing, the injection well location was changed and an additional monitoring well was installed. Injection time was longer than anticipated and adjustments were made while in the field to improve the injection rate. A biotreatability pilot project will be conducted to see if enhanced biotreatment will treat the benzene that was not degraded during the NZVI treatment.
References:
EPA Region 5 http:www.epa.govregion5sitesneaseindex.htm
EPA Region 5 Technology Update #1: Nanotechnology. September 2006. http:www.epa.govregion5sitesneasepdfsnanotechupdatefs1200509.pdf
EPA Region 5 Technology Update #2: Nanotechnology. June 2007. http:www.epa.govregion5sitesneasepdfsnanotechupdatefs1200509.pdf
EPA Region 5 - Latest updates
http:www.epa.govregion5sitesnease#latest
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