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Saint-Gobain halts coating production due to a broken PFAS treatment system

The regenerative thermal oxidizer will burn PFAS chemicals from Saint-Gobain's air emissions in Merrimack. It replaces the factory's old smokestacks, like the one seen at far top left.
Annie Ropeik
The regenerative thermal oxidizer burns PFAS chemicals from Saint-Gobain's air emissions in Merrimack. It replaced the factory's old smokestacks, like the one seen at far top left.

A treatment system that’s meant to minimize the toxic PFAS chemicals emitted by the Saint-Gobain manufacturing facility in Merrimack is broken, and the company has stopped some of its manufacturing work until it is fixed.

Saint-Gobain’s regenerative thermal oxidizer (or RTO) failed last Monday, when its fan shut down unexpectedly. After some repairs, the company restarted the system on Thursday, but the fan failed again Friday morning.

The RTO collects PFAS chemicals from the air and burns them, breaking down the toxic substances before they enter the environment. Exposure to PFAS chemicals can put people at risk for harmful health effects like kidney cancer and abnormally high cholesterol.

Saint-Gobain unveiled the emissions treatment system in 2021 under orders from state regulators, after causing widespread PFAS contamination in nearby water wells.

State testing last year showed that 17 pounds of emissions came through the facility into the RTO, and 2 pounds of those emissions made it out of the RTO, according to Cathy Beahm, an administrator in the Air Resources Division at the state’s Department of Environmental Services.

Beahm said the company is following the state-approved monitoring plan as the RTO undergoes repairs.

“They are not in operation right now and cannot start back up until the RTO is operating at its correct temperature,” she said. “So right now there are no PFOA emissions or PFAS emissions to be concerned about.”

The facility uses PFAS chemicals in coatings that go over protective fabrics, like biohazard suits, that resist extreme weather and chemicals. The company says they have stopped the coating process as they repair the broken emissions treatment system.

“Coating production is halted and will not continue until the new component is installed and the RTO fully operational at the appropriate temperature,” a company spokesperson said in a statement.

In November, New Hampshire lawmakers and community advocates asked the Department of Environmental Services to shut down operations at Saint-Gobain’s manufacturing facility, after state regulators sent the company a letter of deficiency. In the letter, regulators said they observed an unauthorized bypass stack on the emissions treatment system, and that the facility released uncontrolled PFAS emissions during a bypass event in September.

The company said the bypass was a necessary safety feature that had been included on drawings submitted to the town of Merrimack and cited in correspondence with state regulators.

According to Beahm, Saint-Gobain is required to submit a written report of last week’s breakdown, in which the bypass stack was enabled, within 10 days of the RTO shutdown.

Mara Hoplamazian reports on climate change, energy, and the environment for NHPR.

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