Public Notice: Brownfields Remedial Action Plan
Former Sunoco Site and Former Bergevins Site
522 Main Street and 526 Main Street, Keene New Hampshire
The New Hampshire Department of Environmental Services (NHDES) has received the documents entitled Remedial Action Plan (RAP) and Remedial Action Plan Addendum for the 522 Main Street and 526 Main Street Sites in Keene, New Hampshire. These sites are also identified by NHDES as the Former Sunoco and Former Bergevins Sites, respectively. These documents were prepared as a requirement of the state’s Brownfields Covenant Program (RSA 147-F).
The 522 Main Street Site was formerly operated as a gasoline service station, an automotive service garage, and currently, an automotive cleaning and detailing business. Impacted groundwater at the 522 Main Street Property is currently managed and monitored under an active Groundwater Management Permit (GWP-199101014-K-005), issued by NHDES on August 3, 2017. The structures at 526 Main Street were both formerly used for automotive repairs. Prior environmental assessments identified the Site as being improved with a small pottery factory from the 1870s to the 1920s. The main Site building was constructed during 1956 and has been occupied by various automotive repair/maintenance facilities, an electrical parts retail business, and used for gasoline tanker-truck storage. The Site has been vacant and/or used for appliance and vehicle storage since 1993.
The Sites have been characterized during several phases of investigation. Chlorinated volatile organic solvents (CVOCs) have been identified in groundwater above regulatory standards. Based on information available to date, the primary source of shallow CVOC contamination in groundwater is likely a result of contamination from historical localized sources at the Sites (e.g., automotive and degreasing activities) and from unknown sources of groundwater contamination migrating onto the Sites from upgradient off-site properties located in the immediate vicinity. Despite several subsurface investigations completed at both Sites, a discrete source of contamination has not been identified at either property. It is suspected that the source of the CVOCs may be a result of incidental spillage at the Sites, and potentially from releases beneath the buildings from previously active floor drains.
The RAP and RAP Addendum that are the subject of this Notice includes the following remedial activities: 1) Amend the 522 Main Street Groundwater Management Permit to include the 526 Main Street property and associated permanent groundwater monitoring wells; 2) Continued groundwater monitoring and reporting in accordance with the requirements of the Groundwater Management Permit that will be issued for the combined Sites, and any subsequently issued permit renewals; 3) Routine vapor intrusion monitoring for the 522 Main Street building; 4) Installation of a sub-slab depressurization system in a portion of the 526 Main Street building; and 5) Routine inspection and maintenance of the sub-slab depressurization system.
Questions or comments concerning the RAP or RAP Addendum should be directed to:
NHDES Waste Management Division
29 Hazen Drive, PO Box 95
Concord, NH 03302-0095
The comment period will end July 5, 2020.