EPA has approved additional field investigations requested by the General Electric Co. (GE) at the Fletcher’s Paint Works and Storage Facility Superfund Site in Milford, New Hampshire. GE’s contractor, Arcadis US Inc. began these investigations in April 2012. These activities will continue for approximately three months.
Implementation of these field investigations will result in additional data that will reduce uncertainties associated with three elements of the soil cleanup plan: (1) the dewatering rate for the deeper excavation cells at the Mill Street Area; (2) side-wall verification sampling along the proposed vertical excavation supports at the Elm Street Area; and (3) soil characterization to determine the appropriate off-site treatment and/or disposal of the excavated materials. Reducing these uncertainties now could have a significant impact on the sequencing, implementation, schedule and cost of the soil cleanup plan. These investigations will utilize various types of drilling equipment to collect soil samples and to install 5 additional groundwater monitoring wells and two pumping wells.
The soil sampling activities will take place on both the Elm and Mill Street Areas of the Site. The new groundwater monitoring wells will be installed at the end of the Keyes Drive, at the American Legion property and just north of the railroad track at Mill Street, while the pumping wells will be installed at the Mill Street Area.
Information collected from soils will include PCB concentrations and waste characterization data for disposal analysis. The data will be used to support the final location for the support walls needed to excavate the contaminated soils near the River at the Elm Street Area. The pump test activities will allow for a determination of the rate at which groundwater needs to be extracted to enable the installation of support walls at the Mill Street Area, so that the soils being excavated can be dewatered to the extent possible, and loaded into trucks for off-site disposal.
GE will submit the Final Remedial Design incorporating the results of these tests to EPA following these investigations and prior to contracting for the eventual soil cleanup work needed at the Site. GE will also start certain Remedial Action activities in the fall of 2012 which are part of the site preparation efforts needed before soil cleanup can begin. One of these critical activities includes construction of the alternative access road to Keyes Field while Keyes Drive is closed for soil excavation work. EPA plans to present further details regarding these accelerated activities to the public this summer.
On June 15, 2009 EPA amended the 1998 cleanup plan to allow for the excavation and off-site treatment and/or disposal of the highly contaminated soils at the site. EPA added the Site to the National Priority List of Superfund sites in March, 1989. The Draft Remedial Design for the cleanup of the contaminated soils was approved by EPA on September 30, 2011. The Final Design will incorporate modifications from the results of this field work and a change in the final cover of the Elm Street Area to a mixed use cap (engineered soil cover and a parking area).
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Dredging Today Staff, May 7, 2012;