Developing a Robust Conceptual Site Model: A Learning Experience Case Study
Monday, September 23, 2019: 1:00 p.m.
David Sherman, PG
,
Geosyntec Consultants, Inc.
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 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 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.
David Sherman, PG, Geosyntec Consultants, Inc.
Mr. Sherman is a senior environmental project manager who draws on over 20 years of experience in environmental investigation and remediation. He has managed and planned numerous projects, including hydrogeologic investigations; compliance and performance monitoring programs; vapor intrusion assessments; groundwater modeling; air monitoring; and a number of diverse environmental due diligence and remediation projects. Mr. Sherman has served as a consultant to public, private, and government sector clients including industrial, municipal, and state and federal and has expertise with site-wide strategies, hydrogeologic evaluations, remedial characterization, data analysis and interpretation, risk assessment, conceptual site modeling, and site closures.
