Cleanup and final reports on contaminants found on the Council on Aging/Community municipal parcel during construction are almost complete.
During excavation work to build the CoA/CC on January 30, 2023, Tower Construction inadvertently broke open an abandoned concrete underground storage tank that was not on any prior site plans. The surrounding soil tested positive for petroleum-based contaminants exceeding reportable levels as well as low levels of PFAS.
Over the years, site investigations have found several different plumes of chlorinated volatile organic compounds (CVOC), metals, and chlorinated biphenyls (PCBs) in the soil and groundwater across the Rathyeon site that have undergone various ongoing remediation efforts since 2001. Where the new CoA/CC, homes and retail buildings in town center stand today, Raytheon had a research facility at the approximately 83-acre site from 1955 to 1995 until closing in 1996.
Consultant Ben Gould of CMG Environmental, Inc. reviewed the entire Raytheon site status as part of the Public Involvement Plan (PIP meeting) presentation on May 8, noting that the western area wetlands remediation was complete and the northern and southern areas remain in Phase V (monitored natural attenuation) for trichloroethylene and perchloroethylene.
On behalf of Raytheon, Environmental Resources Management Consulting and Engineering, Inc. (ERM) continues to monitor the full site cleanup on a biannual basis to meet regulations of the Massachusetts Contingency Plan, the MassDEP program that oversees waste site cleanups. The site has a principal Release Tracking Number (RTN) 3-13302 with multiple secondary RTNs as further problems have been discovered in the course of the site redevelopment.
The town hired CMG to review ERM’s earlier reports and conduct Phase I environmental site evaluations before and after the May 9, 2022, town acquisition of the 1.96-acre municipal parcel located at 8 Andrew Ave.nue. and to manage the Release Abatement Measure (RAM) plan.
When the underground storage tank was discovered and reported, a new secondary RTN 3-50340 was assigned. Multiple soil stockpiles were created to isolate and identify the contaminants before remediating the area. Raytheon and ERM became involved in the handling and disposal of the stockpiled soils during 2024 as the process proceeded. Questions arose about the need for a vapor barrier under the new building.
The stockpiled soil situation was eventually resolved through the reuse of the soils under MassDEP “similar soils provision” and use of a Non-Regulated Soil Acceptance (NRSA) waiver. The liquid found inside the tank, which contained PFAS above the reportable limits, was removed in three 55-gallon drums and disposed of at a licensed facility.
On May 8, 2025, CMG filed two draft reports to MassDEP providing options for dealing with the underground tank. Lab findings received on May 29, 2025, showed no PFAS6 exceedances in the groundwater. Those results meant CMG had sufficiently completed its March 8, 2023 RAM activities for RTN 3-50340.
The combined RAM and Permanent Solution documents will be finalized and submitted by June 12, 2025, the MassDEP deadline of one year from the incident notification date. Missing that deadline would have pushed the remediation efforts into the next more costly phase in the Massachusetts Contingency Plan process.
