A former solvent recycling facility was used for disposal of distillation residues.
Following remedial actions in the 1980s and 1990s to remove contaminated source materials, a site characterization was conducted, which indicated perched groundwater zones and high concentrations of chlorinated volatile organic compounds (CVOCs) were present in unconsolidated soil. Perimeter area monitoring wells were installed to evaluate karst bedrock groundwater. From 2005 to 2015, soil vapor extraction (SVE) was implemented to treat impacted soil and reduce the CVOC concentrations in perimeter area groundwater; however, clean-up goals were not achieved. Following the SVE remedy, additional Site characterization indicated that groundwater is likely not perched, overburden material remains highly impacted, and dense non-aqueous phase liquid (DNAPL) was observed in one SVE well. Groundwater underlying the source has CVOC concentrations that were much higher than the perimeter monitoring wells.
The initial characterization was not detailed and led to a remedy that could not complete cleanup of the site. To develop a robust conceptual site model, the extent of contamination will be further delineated, and the processes that control transport of CVOCs will be evaluated, with an eye towards effective remedy design and implementation.
- Geosyntec Authors: David Sherman
- All Authors: David Sherman
- Title: Developing a Robust Conceptual Site Model: A Learning Experience Case Study
- Event or Publication: 2019 National Groundwater Association (NGWA) Conference
- Practice Areas: Water and Natural Resources
- Citation: Geosyntec professionals will contribute to the 2019 National Groundwater Association (NGWA) Conference on Fractured Rock and Groundwater at the Hilton Burlington Lake Champlain in Burlington, Vermont on September 23-24, 2019.
- Date: Sept. 23, 2019 at 1:00 p.m.
- Location: Burlington, Vermont