NHDES denial of Merrimack Cease and Desist Order to Saint Gobain Performance Plastics

June 20, 2024

On March 4, 2021, the Town of Merrimack, NH (“Town”) issued a Cease and Desist Order (“Order”) to Saint Gobain Performance Plastics (“SGPP”) under the authority of RSA 485-C:16. In its Order, the Town alleged that the SGPP operations continue to “cause or contribute” to a violation of Ambient Groundwater Quality Standard (“AGQS”) for certain PFAS chemicals. This statement was based on the fact that the regenerative thermal oxidizer (“RTO”) required under Temporary Permit TP-0256 was not installed by the required permit deadline of February 11, 2021 pursuant to the requirements of RSA 125-C:10-e Requirements for Air Emissions of Perfluorinated Compounds Impacting Soil and Water.

Upon review, the Commissioner of NHDES has determined that the Order issued by the Town was based on factually inaccurate information regarding the basis of the annual emission limits contained in the Temporary Permit. The standards used by NHDES in developing annual emission limits to ensure that SGPP no longer causes or contributes to an AGQS violation were not based on EPA Advisories as the Town stated, but rather on PFAS detection levels for current scientific water testing methods.  Finally, the Consent Decree entered into by SGPP and NHDES and filed in Hillsborough Superior Court has addressed the matter of SGPP’s failure to install air pollution control equipment by February 11, 2021, as required by their temporary permit and RSA 125-C:15.

NHDES letter to Town of Merrimack