PFAS Update

As part of Phase II investigations being conducted for the PFAS matter under the Massachusetts Contingency Plan (MCP), Tighe & Bond recently sampled additional surface water in the four locations shown on this map to supplement prior surface water sampling at two ponds known as Schoolhouse Pond and Airport Pond. All of these new results were well below the Surface Water Quality Criteria for PFAS. However, under the MCP, where it appears that the surface water detections may be represent a connection to impacted groundwater rather than surface water runoff, it is necessary to report the data as a “Condition of Substantial Release Migration” (SRM) to MassDEP for their database. Our LSP has notified MassDEP of the SRM, and Tighe & Bond plans on conducting additional surface water sampling in other locations within the PFAS affected area being addressed by the Town. It is normal for groundwater – shallow or deep – to eventually reach surface water, so these results were not unexpected, and they do not require a different approach to the Town’s mitigation program being implemented to monitor and treat private water supply wells. This information will be covered at the October PFAS Information Session which has yet to be scheduled.