Issuance of Temporary Permit for Installation of Equipment to Control Air Emissions of PFAS – Saint-Gobain Performance Plastics, Merrimack, NH

On February 11th, the NHDES Air Resources Division issued a Temporary Permit (i.e. Permit to Construct) to Saint-Gobain Performance Plastics (SGPP) in Merrimack. The permit authorizes SGPP to install air pollution control equipment for the purposes of removing per- and polyfluoroalkyl substances (PFAS). As part of this decision, NHDES determined that the proposed control equipment (a regenerative thermal oxidizer) meets “Best Available Control Technology “, as specified under NH RSA 125-C:10-e Requirements for Air Emissions of Perfluorinated Compounds Impacting Soil and Water.

The issuance of this permit concludes a lengthy public process. On October 4, 2019, the NHDES Air Resources Division issued a public notice proposing to issue the Temporary Permit to Saint-Gobain Performance Plastics Corporation. A public hearing was held on November 5, 2019 in Merrimack, NH, and December 31, 2019 was the deadline to submit written comments.

The issuance of this permit initiates a 30-day period in which any aggrieved party may file an appeal with the NH Air Resources Council.

The final permit and supporting documents related to this action can be accessed below and electronically through the One-Stop Data and Information portal at the following links (Please note our One-Stop Database is currently undergoing upgrades and is unavailable):

Letter to Saint-Gobain Performance Plastics Corporation:
Cover letter to Findings of Fact

Findings of Fact and Director’s Decision:
Findings of Fact and Directors Decision

Attachment 1 of the Findings of Fact and Director’s Decision:
Review of Hydrogen Flouride Health Risks

Final Permit:
Final Air Permit

Final Permit Application Review Summary:
Air Permit Application Review Summary

Final Calculations:
Attachment 1 – Combustion Emissions Summary