FS Engineers, Inc. (FSE) conducted a site assessment and oversaw remedial activities for a proposed 1.7-acre residential
complex in eastern Massachusetts. Portions of the site had been used as an iron
foundry from the mid-1800s through 1971, and historical property uses for abutting parcels included a tannery and a brass
foundry. Previous investigations had been completed at the site and found
various types of fill and debris in the subsurface not suitable as bearing materials.
Based upon a review of historical records and previous investigations, there was also the potential for encountering
abandoned heating oil tanks at the site. Laboratory analytical results collected
during prior subsurface investigations revealed contaminants in the soil in excess of the applicable Massachusetts Contingency
Plan (MCP) Reporting Limits. The site was therefore classified as a “disposal
site” according to the MCP and subject to Massachusetts Department of Environmental Protection (MassDEP) regulations
and reporting requirements.
Prior to construction,
a Release Abatement Measure (RAM) Plan was prepared for the site by FSE and submitted to the MassDEP. The purpose of the RAM Plan was to address the excavation of potentially contaminated soils and subsequent
reuse and/or disposal of the soils encountered during construction at the site. FSE
also prepared the requests for permits for the extraction, treatment, and discharge of groundwater that would likely be encountered
during footing and foundation work within areas of soil and groundwater contamination.
The applications and supplemental materials for General Permit Coverage for Construction Site Dewatering were submitted
the MassDEP and the U.S. Environmental Protection Agency. The approved permit
applications were then presented to the municipal public works department for final approval, prior to groundwater discharge.
During the construction
process, FSE characterized the granular fill, miscellaneous fill, contaminated material, and the natural material underlying
the fill. Based on the analyses of the various soils, cost effective and appropriate
disposal options for each type of material were determined. Due to the presence
of large amounts of unsuitable bearing materials at the site, the project involved extensive geotechnical and foundation work
which was incorporated in the RAM Plan. In addition, due to the location of active
railroad tracks adjacent to the site, tiebacks and retaining walls were used at the site – the specifications of which
were laid out in the RAM Plan. FSE provided construction observation during RAM
activities which were implemented in coordination with the construction sequence to optimize the efficiency of the redevelopment.
Soil Management and Regulatory Closure DocumentsFSE provided the client
with Licensed Site Professional services relative to the excavation and disposal of soils generated from construction activities
including the preparation of Bill of Lading documentation for offsite soil management.
By the completion of the project, about 6,000 cubic yards of fill and 800 cubic yards of contaminated material were
segregated and disposed off-site. Along with the RAM Completion report, a Response Action Outcome (RAO) Statement in Support
of a Method 1 Risk Assessment was completed for the site and submitted to MassDEP, bringing the site into regulatory closure.