The RT3D software, one of the computer codes used in the Battelle Chlorinated Solvent Design Service, was used in the case study described here to design a system for treating trichloroethene- (TCE) contaminated groundwater at McClellan Air Force Base in Sacramento, California.  This case study was an Accelerated In Situ Bioremediation Design, in which the bioremediation team determined the approach and design of a pilot-scale bioremediation system.  Battelle provides accelerated in situ bioremediation designs and other bioremediation services to clients around the country.

McClellan Air Force Base (AFB) was the site for a technology demonstration to remediate TCE in groundwater.  The water table at this site is approximately 110 ft below ground surface and is contaminated with TCE at observed concentrations up to 5 mg/L.  The aquifer sediments consist of alternating layers of sand, silt, clay, and gravel.

EG&G's patented NoVOCs in-well stripping technology was coupled with accelerated aerobic in situ bioremediation to provide a combination of physical removal and biological destruction of TCE.  This synergistic combination of these two technologies takes advantage of NoVOC's ability to remove mobile contaminants while also adding oxygen to the groundwater to support cometabolic biological destruction.  Battelle's role in the project was to use the RT3D computer code to design the bioremediation portion of the combined treatment system.

RT3D was used to determine nutrient injection well locations and nutrient delivery needs:

• The oxygen flux though a vertical slice of the aquifer was simulated to estimate the oxygen distribution and to determine if additional aeration would be required.
• A proprietary, microbial reaction package was developed to simulate the aerobic, cometabolic degradation of TCE.
• RT3D simulations provided details on a feeding strategy that achieved electron donor and oxygen mixing in the locations where the NoVOCs well was least effective.

 

For more information, contact:
Michael Truex Program Manager Field Hydrology and Chemistry Group	Battelle 902 Battelle Blvd., K6-96 Richland, WA 99352 USA	509-376-5461 509-372-1704 FAX mj.truex@pnl.gov