PCB-Contaminated River Remediation & Restoration

When the Housatonic River’s soils, sediments and surface water became contaminated with polychlorinated biphenyls (PCBs), the Environmental Protection Agency (EPA) requested assistance from the New England District U.S. Army Corps of Engineers (CENAE). CENAE awarded Weston one of multiple contracts and task orders to provide comprehensive technical and analytical services for river remediation and restoration.

This high profile program included environmental studies along 126 miles of the Housatonic River. This resulted in: an interim removal action consisting of design and remediation of 95,000 cubic yards of PCB sediments along a 1.5 mile stretch of the River in Pittsfield, MA; human health and ecological risk assessments; hydrologic, hydraulic and hydrodynamic modeling; hydrographic and topographic mapping; database management of over 10,000 samples; remedial and geotechnical engineering; and, large environmental sampling programs. These initial work phases led to more detailed engineering analyses, feasibility studies and remediation cost estimates.

During remediation, given the close proximity of residents and businesses, Weston worked closely with U.S. Army Corps of Engineers, EPA and local stakeholders to implement solutions that were beneficial to all. The design and construction approach featured geotechnical sheet pile cofferdams, a temporary dam and a gravity feed piping system to perform remediation in the dry while allowing natural flow of the river system. Additionally, heavy construction equipment was safely operated along the river bank (in residents’ backyards) and within the channel; channel flow and aquatic and terrestrial resource were reestablished; and contaminated sediments were dewatered and disposed of within a permitted landfill facility adjacent to the project site.