Former Municipal Landfill

A statistical analysis of long-term groundwater monitoring data indicated an increasing concentration trend for several inorganic compounds at one of the perimeter monitor well locations. In response to this finding, the regulating agency requested corrective actions.

SES Environmental initiated the project by conducting a detailed review of all available geologic, hydrogeologic, and geochemistry data available for site. The results of this review indicated a high probability that the suspect monitor well installed in the early 1980s may have been improperly constructed. More specifically, information on a boring log for the suspect well indicated a shallow, thin sand seam was encountered. This shallow sand seam appeared at an elevation that would correspond to the adjacent landfill operation. It was surmised this sand seam might be hydraulically connected to the landfill. SES designed an investigation to test this hypothesis. The investigation included soil borings and monitor well installations to document stratigraphy, gamma logging to assess the relative positioning and continuity of the various sand layers, and a groundwater geochemical statistical analysis to more fully evaluate localized groundwater quality. Results of this investigation indicated the suspect well was not screened within the appropriate aquifer. Corrective actions included decommissioning the suspect well and the installation of a new well.