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Beltsville Agricultural Research Center Groundwater Treatment

For over 15 years, BMT has supported cleanup of Areas of Concern (AOCs) at the U.S.

For over 15 years, BMT has supported cleanup of Areas of Concern (AOCs) at the U.S. Department of Agriculture’s (USDA) Beltsville Agricultural Research Center (BARC) in Maryland. One AOC, dubbed BARC 32, consisted of transformers containing polychlorinated biphenyls (PCBs) that had leaked PCB-containing fluids. Soil was contained other environmental contaminants, including pesticides, metals, and polynuclear aromatic hydrocarbons (PAHs).

BMT delineated contamination using a variety of investigation technologies that included historical aerial photography; sampling soil and groundwater using Geoprobe® direct push methods; and field immunoassays to produce real-time data that expedited the assessment and cleanup.

An expedited Time-Critical Removal Action (TCRA) was implemented to ensure that contaminants were removed and potential exposures were minimized. The removal action addressed over 800 tons of highly concentrated PCB wastes. In addition, over 8,000 tons of soil was sent to a Low Temperature Thermal Desorption (LTTD) facility to separate contaminants and allow the soil to be recycled.

BMT identified the presence of groundwater contamination with chlorinated volatile organic compounds (VOCs) consisting primarily of Tetrachloroethene (PCE). An important aspect of our work is the development of groundwater treatment options. BMT evaluated several treatment technologies to reduce PCE levels in groundwater to acceptable levels, and developed an approach using a proprietary treatment technology using “OSorb®.”

Osorb® is a silica absorptive material used for the capture of a broad range of groundwater contaminants. Iron-Osorb® is a version of Osorb® which uses embedded micro iron to reductively dechlorinate chlorinated solvents such as PCE, trichloroethene (TCE), cis-1,2-dichloroethene (DCE), and vinyl chloride.

This approach was brought forward to ARS and EPA as a way to cost-effectively address PCE in groundwater. Bench tests demonstrated the ability of the Osorb® material to prevent further migration and reduce concentrations of PCE. BMT continues site monitoring.

 

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