LEP Services for Voluntary Remediation at Former Power Plant and Coke Works

GEI provided a full range of environmental consulting services to The United Illuminating Company (UI) starting with divestiture of its electric generating facility in New Haven. The site includes a one-unit power plant constructed in 1974 located on over 60 acres. The property was previously a coke works operated by the Connecticut Coke Company.

Initial Phase I assessments involved detailed site inspections, interviews, 150-year site histories, state regulatory file reviews, state and federal database searches, and municipal records searches. The Phase I assessment was conducted concurrently with a detailed internal UI environmental file review to determine permitting/violation status for the site.

Phase II/III field investigations were also completed at the site. Borings and wells were installed and hundreds of samples were analyzed. The investigations also included hydraulic conductivity testing, tidal surveys, and ecological assessments. All field and analytical data were managed in a database that allowed for the timely and accurate presentation of data in the final reports. All data were compared to the applicable regulatory guidelines and remedial options were developed for the various constituents/areas of concern. GEI completed these investigations within the aggressive schedule and assisted UI in assembling the environmental compliance data room.

Environmental permits were identified, assembled, and evaluated.

Using digitized aerial photographs and contaminant concentration overlays, GEI prepared a presentation that summarized the results of the site investigations. The presentation was delivered to potential buyers during a two-month due diligence period in which GEI assisted the UI management team in responding to questions and issues regarding the environmental status of the facility.

The portion of the site containing the power plant was sold. UI retained the northern portion of the site which is 19 acres in size and includes a substation, a vehicle fueling facility, and two buildings for meter testing and service offices. This retained parcel is referred to as the East Shore facility.

GEI prepared an environmental conditions assessment form to enter this site into the state’s voluntary remediation program. Additional investigations have been completed to address data gaps, and a remedial action plan (RAP) has been prepared. A key component of the RAP is the use of engineered controls. As required by state regulations, GEI submitted a request to the state to obtain approval to use engineered controls (i.e. caps) at the site. One cap, addresses an area containing tars from former coking operations. This cap is impervious and includes a synthetic membrane liner. The other cap address soils, coal and ash that contain substances, such as arsenic, which are present at concentrations above the direct exposure criteria. This cap is pervious and is constructed of soil in some areas and asphalt in other.