DES: Saint-Gobain demolition nearly complete; agency seeks soil-distribution work plan for consent-decree area

At the Sept. 12, 2025 meeting of the Legislative Study Commission on the Environmental Health Effects of PFAS, a DES representative reported that demolition of the former Saint-Gobain facility is nearly complete and that company-funded clean-water remedies have advanced but that soil management and long-term groundwater monitoring remain major unresolved issues.

"The demolition of the former facility is nearly a 100% complete," the DES presenter said, and noted only a concrete slab remains while the company completes decommissioning work requiring railroad access. DES said Saint-Gobain is evaluating potential PFAS leaching from the remaining concrete using EPA leaching-test approaches and that results are expected in coming months.

DES summarized remedial and replacement-water work completed under the parties' consent decree and associated term-sheet attachments: contractors have installed approximately 748 point-of-entry treatment (POET) systems (707 of them considered officially complete), and dozens of municipal waterline connections have been completed in Merrimack, Bedford and other towns. DES said a recent report summarized installation efforts and system monitoring through March 31, 2025, and that bottled-water deliveries have been discontinued at properties where meters have been installed. The presenter said the company has sampled about 1,300 eligible properties under a revised groundwater monitoring work plan and expects to sample roughly 150–200 properties per month.

DES reported that 111 additional properties were identified as exceeding the state's ambient groundwater-quality standard (PFOA) during the revised sampling program and were offered bottled-water remedies under the consent decree. DES also said it had accepted a company work plan to sample previously unsampled areas at the edge of the consent-decree boundary (Bedford and Litchfield) and that Saint-Gobain intends to sample those properties twice before February 2026.

On soils, DES told commissioners it had asked Saint-Gobain in a Sept. 8 letter to submit a work plan (due Nov. 7, 2025) to evaluate PFAS distribution in soils within the consent-decree outer boundary and to develop guidelines for soil management practices. The agency said the scale of potential soil contamination presents unique management challenges because the area spans tens of square miles; DES staff said they want practical, protective approaches that avoid forcing every excavated yard of soil into a landfill.

Community members and commission members urged more timely and visible action. Maureen, a commission member and long-time local resident, pressed the parties on follow-up sampling in the epicenter area and said, "We have a responsible party ... they haven't ... been held fully accountable for the environmental damage that they've done." Another commissioner warned that delays in resolving where contaminated soils can be managed could slow municipal infrastructure projects such as a planned bridge replacement in Merrimack.

DES also described ongoing regulatory and technical timelines: the state's ambient groundwater standard is currently 12 parts per trillion (ppt); federal drinking-water MCLs (proposed at 4 ppt for certain PFAS) are being phased in and will have separate implementation timelines for public water systems. DES staff said that once the federal MCL is adopted and the state ambient groundwater standard is adjusted, the consent-decree remedies could be enforced to the lower state standard.

DES said it will continue to review company submittals, requested a final demolition and decommissioning report from Saint-Gobain, and plans to share comments on the recent remedy-installation report. Commissioners asked DES for clarification on sampling counts and status reports; DES said it will provide updated numbers and meeting notes to the commission clerk.