The Saint-Gobain factory in Merrimack is putting the finishing touches on a big new air emissions treatment system, a state-mandated upgrade designed to burn off harmful PFAS chemicals that represents a first for the company.
They unveiled the new system to reporters as part of a factory tour on Tuesday.
Inside the plant, Saint-Gobain's signature protective fabrics were being woven on giant looms and coated with chemicals that include kinds of PFAS, also known as "forever chemicals."
The substances are linked to health problems and persist in the environment. New Hampshire is one of the few states that regulate PFAS in drinking water, but they remain common in consumer products and aren't subject to federal limits.
Saint-Gobain uses the substances to make fabrics that resist chemicals, fire and the elements for military and emergency gear – biohazard suits and desert shelters, for example – and construction uses, such as weather-proof sports stadium rooftops.
“We make products here [in Merrimack] we don’t make at other facilities,” said Chris Angier, the company’s regional environmental health safety manager. “There’s kind of some unique things that take place here.”
After Saint-Gobain’s PFAS use in Merrimack caused contamination in hundreds of nearby water wells several years ago, state regulators ordered the company to install the new air emissions treatment system.
Saint-Gobain missed its first deadline this past February. The final deadline is July 30, 2021.
"A very difficult time"
The company said the $5.3-million project marks the first time they’ve used this technology, called a regenerative thermal oxidizer, to treat PFAS at their facilities. It’s more commonly used to eradicate volatile organic compounds, which are also toxic.
The oxidizer replaces all of the factory’s old rooftop smokestacks with a large system of ducts, heating chambers and a bright blue tower on the outside of the building. It includes three large ovens, which collect PFAS-laden air and burn off the chemicals at more than 1,800°F.
The system is now ramping up to its required temperature and capacity, and the company says it will be fully operational by the state’s deadline.
Saint-Gobain’s Merrimack plant manager Gabriel Caridade said the project has taken 32,000 labor hours to complete, almost all over the past four months, often including six- or seven-day work weeks. He said he and his workers are glad the project is done.
“This has been a very difficult time for them,” he said at the factory Tuesday. “We are very proud of this.
Angier, the environmental safety manager, said he’s confident the device will address local concerns about pollution from the plant.
“It’ll destroy PFAS, it’ll meet the state-required conditions,” he said, “so I’m optimistic.”
Waiting for proof
Town officials want to see the data to prove that the new system is effective, after years of tension with the factory, which they called a public nuisance in a recent lawsuit.
“It’s great that it’s being finalized, finally,” Merrimack town council chair Tom Koenig said Wednesday. “We are definitely waiting for the required studies to formalize the functionality of all this.”
Those studies will include a company analysis of the oxidizer’s hydrogen fluoride emissions, which the town wants addressed with a scrubber to prevent further health risks.
The company is also completing a state-mandated study of PFAS in rainwater around the facility, and it’s still installing new water lines for neighbors with contaminated wells.
The permit for the air oxidizer includes a 60-day follow-up period in which the company will gather data for the state on whether the system is working as expected.
The plant reduced its operating hours by about 40%, without furloughing workers, while the oxidizer was under construction, in order to reduce PFAS emissions to state specifications. They say they’ll return to full strength once the system is finalized next week.
