RI/FS Former MGP Site - Manchester Street Power Station

New England Power Company completed a major conversion of the Manchester Street Power Station, located on a 30-acre property adjacent to the Providence River, from oil to natural gas. The conversion required multi-million dollar construction, including a new turbine/generator plant adjacent to the existing plant, relocation of existing oil tanks, and a public access park along the river.

During the preliminary investigation for the repowering project, the utility discovered that a former manufactured gas plant (MGP) had been located at the site. The State of Rhode Island Department of Environmental Management (RIDEM) required that a remedial investigation/ feasibility study (RI/FS) be performed before they would grant approval for the siting of the plant to continue.

GEI was engaged to perform the RI/FS site investigation within a
5-month period. GEI prepared a detailed work plan that was submitted to the state and approval granted for the repowering project to continue. Within the allotted time, GEI completed the following work:

• Detailed site history evaluation involving historical plans, a field survey, and integration of the data on AutoCADD_TM to determine the limits of the former MGP
• Field investigations; sampling and analysis of ground water, subsurface and surface soils, marine sediments and surface water, ground water elevation measurements during tidal cycles; and a soil gas survey
• Public health and environmental risk assessment for present and future conditions
• Remedial investigation report
• Feasibility study to evaluate and select recommended remedial actions
• Meetings and negotiations with state and utility regulatory agencies.
• GEI continues to provide consultation and long-term environmental monitoring at the Manchester Street Station.