Background
The Fossa Ave VI Site is located at 9-11 Fossa Avenue in
Nashua, New Hampshire. The Site is .7 acres consisting of two multi-unit
townhouse buildings and two multi-unit storage sheds owned by the Nashua
Housing Authority (NHA). Adjacent properties include residential properties to
the North, South, and East and Salmon Brook to the West.
The Site was undeveloped prior to 1912. G.F. Fossa Steam
Laundry operated from the 1940s to the mid-1970s. It was vacant from the
mid-1970s to 1980, and the existing multi-unit residential townhouse buildings
were constructed in 1981.
During an assessment near the Site
by an engineering consulting firm in 2012, chlorinated volatile organic
compounds (CVOCs) were detected in the groundwater at concentrations exceeding
their respective NHDES groundwater quality standards. The CVOCs detected were
typically associated with dry cleaning solvents and their breakdown products.
The firm concluded that the source of the CVOCs was from an off-site source,
namely the former laundry business located on the property.
What has been done to clean up the site?
Site investigations and air sampling have been conducted
on-site since 2016 by the NHA and New Hampshire Department of Environmental
Services (NHDES). A vapor mitigation system – a structure or mechanism designed
to prevent harmful vapors (CVOCs) from entering a building - was installed at 9
Fossa Avenue in 2023.
EPA conducted a preliminary assessment/site investigation
(PA/SI) in January and July 2024. A contaminant called Perchloroethylene (PCE)
was identified in soil gas at the Site above EPA’s vapor intrusion screening
levels.
What is the current site status?
EPA signed an Action Memorandum on December 4, 2024, to
install a vapor mitigation system at 11 Fossa Avenue. Work is expected to be
complete by Spring 2025. The Agency will coordinate with residents and the City
of Nashua about ongoing site activities.
