Remediation using Large Diameter Auger with Steam and Zero Valent Iron
Tetrachloroethylene (PCE) concentrations in groundwater in the source zone of a former syringe manufacturer were indicative of dense non-aqueous phase liquid (DNAPL). Distinctive to the Site, the upper surficial aquifer is separated from the lower surficial aquifer by two clay layers with a vertical head gradient (downward) across the clay layers of 40 feet. The significant head difference resulted in the vertical downward migration of the PCE DNAPL into/within the clay layers and then forming a large plume in the lower surficial aquifer beneath the clay layers. Over time, migration of the contaminants, including PCE and its breakdown products, resulted in an expansive dilute dissolved plume throughout a residential area with multiple private water supply wells. The primary project objective was to refine the existing conceptual site model and develop and implement a remedial strategy to address the PCE/DNAPL source material diffused within the clay layers and representing a long-term source of flux to the dissolved plume.
