Not identified in the references cited.
Targeted Environmental Media:
 Dense Non-aqueous Phase Liquids (DNAPLs) - Fractured Bedrock
Not identified in the references cited.
Major Contaminants and Maximum Concentrations:
- Trichloroethene (0 µg/L)
No technologies selected.
- Bioremediation (In Situ)
- Reductive Dechlorination (In Situ Bioremediation)
Comments:
Naturally-occurring dechlorination of tetrachloroethene (TCE) was taking place on site; however, a recirculation-based enhanced in situ bioremediation (EISB) system was implemented in 2008 to prevent plume migration and to accelerate dechlorination. EISB was selected based on various technical and practical factors such as the existence of nearby wetlands, the ongoing naturally-occurring dechlorination, restrictions on near-by sewer use, and facility and neighboring operations.
The EISB system includes:
ýGroundwater extraction wells (3)
ýAmendment infrastructure for ethanol (electron donor) and bromide (tracer)
ýInfrastructure for chlorine dioxide addition (biofouling control)
ýRecharge wells with operating capacity of 100 gallons per minute (5)
Not identified in the references cited.
From 2008 to 2010, the system has reduced cis-1,2-DCE concentration at the site boundary by more than 70 percent and dechlorination within the source area is slowly increasing. In the fall of 2009, KB-1ý will be injected into the plume in areas with the highest TCE concentrations to facilitate bioaugumention.
Elevated sulfate levels (>500 mgL) are being reduced and the sulfide production in the groundwater is restoring EISB dechlorination rates to initial levels. Dechlorination and Dehalococcoides are being monitored for further impacts from sulfide production.
|
