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.
After site activities were delayed approximately 9 months during consultation meetings with the NH Division of Historical Resources and the Advisory Council on Historic Preservation, a Memorandum of Agreement was reached on September 23, 2005. Upon signature of the MOA, final recordation activities were completed and removal activities resumed on October 24, 2005. An Asbestos survey and abatement was completed prior to the start of building demolition activities.
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. Remobilization is planned for the spring of 2006 to complete removal of the contaminated soils.
Removal of contaminated soils is planned for June 2006. All soils will be transported to a licensed disposal facility. The property will be regraded and seeded prior to final removal activities at the site.
|