October 1999 Groundwater Sampling and Data Analysis, Distler Brickyard Site, Hardin County, Kentucky

This report describes the results of a sampling event conducted at the Distler Brickyard Superfund Site, Hardin County, Kentucky, October 1999. The purpose of the sampling event was to evaluate the extent of natural biodegradation of chlorinated aliphatic hydrocarbons (CAH) occurring at the Site. Sampling locations were selected to evaluate three areas of the suspected CAH plume: the source area, an axial cross-section, and a downgradient transect. Due to inadequate recharge to and the poor physical condition of some monitoring wells at the Site, the sampling approach was modified to reflect wells that could be sampled. Results indicate that natural anaerobic degradation of chlorinated aliphatic hydrocarbons is occurring in the presumed source area around monitoring well GW-11. The primary contaminant of concern, trichloroethene, migrates downgradient from the source area into the Coarse Grained Alluvium Aquifer at concentrations slightly greater than the Maximum Contaminant Level (MCL). Based on the available, the following hypothesis is proposed: the source area has been remediated through soil removal activities and subsequent anaerobic reductive dechlorination. If this is the case, this Site may be a good candidate for implementation of a monitored natural attenuation remedy. However, more data are necessary before this hypothesis can be confirmed