Soil composition at the aquifer level, groundwater quality and the presence of Dehalococcoides ethenogenes at Dover AFB
Chlorinated solvents are among the most common groundwater pollutants globally. A common method to remediate this groundwater pollutant is through bioremediation. One of the most important bacteria that remediation workers use in this remediation is Dehalococcoides ethenogenes, which are the only dehalogenating bacteria with the capacity to break down these contaminants to the non-chlorinated compound, ethylene. While much is known about these bacteria in the laboratory, little is known about their natural habitat. In this experiment, eight sites on Dover Air Force Base were selected based on the larger CERCLA Closeout project; 2.54 cm wells were installed and groundwater samples were collected. These sites monitored groundwater quality parameters: temperature, pH, dissolved oxygen, and oxidative reduction potential. Additionally, samples were also analyzed for the contaminants: tetrachlorethylene, trichloroethylene, and vinyl chloride. The presence of vinyl chloride is an indicator of Dehalococcoides ethenogenes. Soil samples from the aquifer level were taken from each site as well and soil particle texture was assessed using the Bouyoucos hydrometer method. The objective of this experiment was to determine if there was a relationship between clay particles at the aquifer level, groundwater quality, and the presence of Dehalococcoides ethenogenes.
KeywordsGroundwater contamination Dehalococcoides ethenogenes Dover Air Force Base USA
The author would like to thank Lee Mitchell and Tom Feller from SCF, Dale Williams, Robroy Young, and Bill Ahlers from Oak Ridge National Laboratory and the sampling crews from URS for assistance with data and fieldwork. I would also like to thank Dr. Bruce Allison for his work on this paper and presentation.
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