Remediation for PCE in Groundwater at Former Medfield State Hospital

Weston & Sampson was selected by the Division of Capital Asset Management and Maintenance (DCAMM) to provide remediation services at the former Medfield State Hospital.

Historical laundry operations at a hospital led to groundwater contamination with tetrachloroethylene (PCE) and its byproducts. After evaluating remedial options, our team implemented In-Situ Chemical Oxidation (ISCO), injecting 20,000 gallons of sodium persulfate at 40 locations. Due to tight soils and contaminant rebound, further action was needed. A targeted field investigation and cost analysis led to selecting In-Situ Chemical Reduction (ISCR) using zero valent iron (ZVI). Soil blending with ZVI at the source area and installation of a Permeable Reactive Barrier downgradient were chosen to address low permeability and reduce migration. We provided design, construction oversight, and continues long-term monitoring, achieving cleanup standards for PCE.