PROJECT:
Remediation of PCB Contaminated Caulk in University Housing

Cooperstown Environmental was retained by the Massachusetts Institute of Technology (MIT) to oversee the remediation and restoration of a graduate student housing complex with graduate students and young children during the school year while these buildings were fully occupied.

The Westgate complex on the western end of the Cambridge campus was constructed in the early 1970’s, and during a facility upgrade and window and door replacement program in the late 1970’s a type of polymer caulk was used that contained high concentrations of PCBs to improve material durability, resistance to degradation and as a softener/plasticizer for improved application. Sampling of these caulk materials during a reconstruction program led to the discovery of elevated concentrations of PCBs and subsequent investigations uncovered leaching and transport of high concentrations of PCBs into the surrounding building materials and soils.

The remediation was planned and coordinated in conjunction with requirements under the Massachusetts Contingency Plan as well as under a risk-based cleanup plan approved by the U.S. Environmental Protection Agency, and after a series of pilot programs to determine the most effective cleanup approach, the work was initiated during the summer of 2008. The work entailed the removal of the PCB-laden caulk using chisels and small hand instruments to minimize the vibratory impact and interruption of power tools. As residual materials were removed a two-part epoxy encapsulant was applied to ensure that any PCBs that had leached into the surrounding brick materials would not be accessible.

Following the removal and encapsulation of the building materials, Cooperstown Environmental oversaw the removal of several hundred tons of contaminated soils surrounding the buildings. Subsequent human health risk assessment studies using post excavation sampling data were employed to support a finding of no significant risk and the site was restored to its original state.

A significant component of Cooperstown Environmental’s program oversight was dedicated to managing the public participation activities and resident expectations during the year it took to fully remediate the site. A Cooperstown Environmental representative was on site daily to oversee contractors and remediation specialists, but more importantly, was available to answer questions from the residents and to address the campus community in a series of town-hall styled meetings as the program progressed.

Communications with residents were coordinated through resident advisors and using a web blog to ensure ready and equal access by any members of the public or student community. All questions and answers became part of the public record for this project. An open dialog between the community and MIT’s environmental management department was instrumental in the overall success of this project.

The work performed during this lengthy remediation has been cited by EPA Region I as one of the largest and most successful remediation efforts addressing the complex problem of removing PCB-laden caulk from occupied buildings, and the approach will be used as a model for similar projects in the Region.

CLIENT: Massachusetts Institute of Technology Department of Environmental Health and Safety

LOCATION: Cambridge, Massachusetts