The Feasibility Study (FS) evaluated a variety of alternatives to achieve the Remedial Action Objectives (RAOs) for the various affected media. Based on the FS, EPA in it’s Record of Decision (ROD) dated September 30, 2005 selected a remedy for the Site that consists of the following major components:
- Design, construct and operate an in-situ thermal treatment system to treat contamination in the Overburden NAPL Area. A general description of this technology is provided in the EPA Citizen’s Guide to In Situ Thermal Treatment.
Figure: Thermal Treatment Area
- Excavate contaminated soil and wetland soil from the Cianci Property and culvert outfall. A general description of this technology is provided in the EPA Citizen’s Guide to Excavation of Contaminated Soil.
Figure: Soil and Sediment Area
- Remove existing concrete culvert; re-route drainage from the Site to the Quinnipiac River through a new, impermeable pipe. Completed November 2012.
- Design and construct a low-permeability, multi-layer, composite RCRA Subtitle C cap over contaminated soil in the Operations Area and along the Railroad Right-of-Way. A general description of this technology is provided in the EPA Citizen’s Guide to Capping.
Figure: Capping Area
- Design, construct and/or operate and maintain, as necessary, a hydraulic containment, extraction and treatment system for groundwater in the overburden and bedrock aquifers. A general description of this technology is provided in the EPA Citizen’s Guide to Pump and Treat.
- Monitor natural attenuation of the groundwater in the Severed Plume that exceeds cleanup levels. Monitor natural attenuation of the NAPL in the overburden aquifer that lies outside the Overburden NAPL Area and in the bedrock aquifer underlying the Site. A general description of this technology is provided in the EPA Citizen’s Guide to Monitored Natural Attenuation.
- Implement any institutional controls determined by EPA to be necessary to restrict future use of Site property and groundwater. Monitor compliance and enforce, and/or assist EPA and CT Department of Energy and Environmental Protection (CT DEEP) in enforcing, such institutional controls.
- Restore the functions and values of any and all habitats affected by the remediation.
- Assist EPA in performing five-year reviews to evaluate effectiveness and protectiveness of the remedy.
- Design and implement a long-term groundwater monitoring program to evaluate the performance of the Hydraulic Containment and Treatment System and the overall effectiveness and protectiveness of the remedy, including the MNA component.
- Implement changes to the selected remedy to meet the ROD requirements that may be necessary as a result of remedial design and construction processes.