Targeted Brownfield Assessment and Cleanup of Former Manufactured Gas Plant Site, 260 River Street, Montpelier, Vermont
Stone was hired by the Vermont Department of Environmental Conservation in spring 2017 to assess a former manufactured gas plant (MGP) site along the banks of the Winooski River. The project involved a comprehensive evaluation, including a Site-Specific Quality Assurance Project Plan and a Conceptual Site Model (CSM) to understand contaminant releases and their impact. Fieldwork in the Phase II ESA identified coal tar releases, leading to groundwater, soil, and sediment contamination. A Supplemental Site Investigation and an Evaluation of Corrective Action Alternatives (ECAA) followed, resulting in a selected remediation approach for different contamination areas. Stone submitted a Corrective Action Plan (CAP) in August 2019, securing approvals and permits for cleanup activities, which began in late 2019 and continued into 2020. The site underwent redevelopment, incorporating engineered barriers and institutional controls for managing contaminated soil, culminating in a Certificate of Completion under Vermont’s Brownfields Reuse and Environmental Liability Limitation program (BRELLA) in June 2022. Stone remains engaged in ongoing groundwater monitoring in compliance with regulatory requirements.