BOSTON - E.P.A. has completed the "Record of Decision" (ROD) for the Nuclear Metals, Incorporated Superfund Site, located in Concord, Massachusetts The ROD outlines a detailed project for cleaning up contaminated soil, sediment and groundwater at the Site.
The ROD explains the various cleanup options chosen by E.P.A. for the Site. E.P.A. selected a cleanup that includes excavation and off-site disposal of sediments and soils located outside of the Holding Basin, stabilization of Holding Basin soils, and containment of those soils with a vertical wall and horizontal cover. The ROD also includes treatment and monitoring of groundwater at the site. The approximate cost for EPA's cleanup decision is estimated to be approximately $125 million.
"EPA is pleased to complete this milestone and prepare to implement further cleanup at the Nuclear Metals site," said Curt Spalding, regional administrator of EPA's New England office. "Our goal with this remedy is to protect human health and the environment by preventing risk of exposure to contaminants still present at the site."
A Remedial Investigation conducted at the Location was completed in April 2014. The investigation summarized the nature and extent of the Site's contamination and was used to prepare a Feasibility Study, completed in Oct. 2014, which identified all of the options E.P.A. considered for the cleanup. The study evaluated different combinations of cleanup options (or "alternatives") to restrict access to, contain, remove, and/or treat contamination to protect human health and the environment by preventing risk of exposure from site-related contaminants in soil, sediment, and groundwater.
The ROD generally includes the following components:
• Excavation and off-site disposal of approximately 82,500 cubic yards of contaminated materials.
• In-Situ stabilization of depleted uranium contaminated soils in the Holding Basin using apatite injection.
• Extraction and ex-situ treatment of groundwater for volatile organic compounds (VOCs) and 1,4-dioxane.
• In-situ treatment of depleted uranium and natural uranium in groundwater.
• Long-term monitoring to monitor the effectiveness of in- and ex-situ treatment.
• Institutional Controls to prevent disturbance of the Holding Basin area, prevent the use of Location groundwater, and address potential vapor intrusion risks.
As part of this ROD, E.P.A. has also decided to accelerate the cleanup of 1,4 dioxane in groundwater by initially addressing the contamination under Non-Time Critical Removal Authority. Recent sampling indicates that the 1,4 dioxane plume may be migrating underneath the Assabet River. Beginning the groundwater remedy for 1,4 dioxane before the rest of the suggested remedial action would contain this plume from expanding further, thereby avoiding the increase in time and cost for this component of the remedy. The ROD provides additional information regarding risks at the Location relating to 1,4 dioxane in groundwater.
The Nuclear Metals, Incorporated property is located on a 46.4-acre parcel located at 2229 Main Street in Concord, Massachusetts The property is bordered to the north by Main Street, commercial and residential properties, and the Assabet River; to the east by woodland and residential properties; to the west by woodland and commercial/industrial properties; and to the south by woodland and residential properties. In 1958, Nuclear Metals, Incorporated (NMI) began operating a manufacturing facility on previously undeveloped land. Nuclear Metals, Incorporated produced depleted uranium products, primarily as penetrators for armor piercing ammunition. They also manufactured metal powders for medical applications, photocopiers, and specialty metal products, such as beryllium tubing used in the aerospace industry. Operations at the Location resulted in contamination of soils, sediments, and groundwater.
E.P.A. has taken 2 time-critical removal actions, one in 2002 and one in 2008, to address materials which presented more immediate risks at the Site. In 2011, a Non Time-Critical Removal Action began at the Location to address the contaminated buildings, this removal action is ongoing.
More information:
Background on EPA's work to assess and cleanup contamination at the Nuclear Metals Superfund Location (including electronic copy of the ROD):
(http://yosemite.epa.gov/r1/npl_pad.nsf/f52fa5c31fa8f5c885256adc0050b631/7B6349F1A22FFDF3852569E5006CA840?OpenDocument)
The ROD is accessible at: http://semspub.epa.gov/src/document/01/582996
The ROD will also be accessible in the Nuclear Metals Location repository located at the Concord Public Library, 129 Main St., Concord, Massachusetts
