VERTEX was retained by a national, multi-family housing developer to assess and remediate the site of a former gasworks building and gas holder associated with a former Manufactured Gas Plant (MGP) in preparation for construction of a 16-story residential building.
VERTEX was retained to conduct soil management during the construction of the residential building on this former commercial/industrial site. Prior to demolition of the existing structures, VERTEX conducted a comprehensive pre-characterization field investigation to evaluate soil disposal alternatives for urban fill soils impacted by historical use by chlorinated volatile organic compounds (VOCs), petroleum, and metals. Prior to the commencement of construction activities, residual coal tar contamination associated with the former gas holder was identified in soil between 30 and 40 feet below the ground surface. Further investigation in the impacted area identified non-aqueous phase liquid (NAPL) in several wells.
VERTEX conducted an Immediate Response Action (IRA) under the Massachusetts Contingency Plan (MCP) consisting of several shallow and deep monitoring wells to assess the nature and extent of the release. The existing monitoring wells were decommissioned, and construction of the building was completed. Following building completion, replacement monitoring wells were installed to monitor groundwater quality. VERTEX determined that the contamination is limited to a narrow layer and is not impacting site groundwater. VERTEX is in the process of demonstrating that there are no existing exposure pathways for residual impacts and that the NAPL is stable and non-mobile and can therefore remain in place.
The project achieved the client’s goals enabling them to move forward with the construction of the residential building. The redevelopment of the site has been viewed favorably by the community because the work addressed the long-term environmental issues present at the site.