The approximately 0.4 acre site is located in a mixed commercial and residential area in Chesterfield, NH. The Site is comprised of two separate and abutting parcels, identified as Lots# 5 and 5.1 of Map 6A, Block D at the Chesterfield Tax Assessor's Office. The Site includes two main commercial buildings, one small building that formerly housed a portion of an industrial wastewater treatment facility and an on-site septic leachfield which was used by both parcels.
Historical records indicate the primary building was constructed around 1810 and was originally used for manufacturing textile and wood-based products until the 1930's. During the 1940's the buildings were used as a warehouse until it was sold to Electrosonics in 1966. Electrosonics manufactured printed circuit boards until 1984. It has been reported that Electrosonics discharged untreated wastewater contaminated with various volatile organic compounds (VOC's) and heavy metals into an on-site septic leachfield. This caused the leachfield to suffer frequent surface breakouts that resulted in waste effluent flows into Partridge Brook. Other reports have indicated that portions of the wastewater were discharged into the earthen basement floor of the original mill building. It is believed that for several years, after a newly built wastewater treatment facility was brought on-line in 1974, there were no discharges into the ground or the Partridge Brook.
After circuit board manufacturing operations ceased in 1984, different portions of the former Electrosonics facility were used for warehouse and office space by several owners/operators.
During the 1980's and 1990's, the New Hampshire Department of Environmental Services (DES) conducted several inspections and concluded that the leachfield periodically failed and resulted in discharges to Partridge Brook. DES sampling of on-site monitoring wells detected elevated levels of VOC's in the groundwater. The contaminated soils at the Electrosonics site have been identified as the source of the VOC's in the groundwater. DES installed point-of-entry (POE) treatment systems on four homes near the site which draw their drinking water from private wells. The POE systems are currently still operating in the four homes.
Since the Site was a former mill, and it would be necessary to demolish some of the buildings in order to gain access to the contaminated soils beneath the building, OSC Young coordinated with the New Hampshire Division of Historical Resources (DHR) to determine if the main building located on Lot# 5.1 was eligible for the National Register of Historic Places. After site activities were delayed approximately 9 months during consultation meetings with DHR, the Federal Advisory Council on Historic Preservation (ACHP) and the Town of Chesterfield, a Memorandum of Agreement (MOA) was reached on September 23, 2005 which outlined the terms for recording the building, in accordance with Section 106 of the National Historic Preservation Act (NHPA), prior to demolition. Upon signature of the MOA, final on-site recordation was completed and removal activities resumed on October 24, 2005.
An Asbestos survey and abatement was completed prior to the start of building demolition. Building demolition and disposal of the materials was completed on November 14, 2005. EPA secured the site for winter hiatus and demobilized from the site on November 16, 2005. Removal of the contaminated soils was scheduled for Spring/Summer 2006.
Excavation and site restoration activities were completed during the week of August 7, 2006. Maps are being developed by the START contractor which will define areas that were excavated for future use by the State of NH and the Town of Chesterfield.
Installation of the holding tank to replace the leach field removed as part of the excavation of contaminated soils will occur during the week of October 9, 2006. EPA will provide site maps and final sampling data to the State of NH and the Town of Chesterfield.
Final drafts of the recordation reports will be submitted to EPA during the week of October 2, 2006. Completion of the final recordation report is expected during the week of October 23, 2006.
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