Read the full article by Kimberly Houghton

“MERRIMACK — The Saint-Gobain facility in town is still releasing small amounts of polyfluoroalkyl chemicals from its smokestacks, which could be contributing to local groundwater contamination, according to officials.

The New Hampshire Department of Environmental Services is now requiring that the Saint-Gobain plant investigate and apply for a permit to install air pollution controls on its local facility.

‘This request comes as a result of two years of investigation by NHDES, and the authority provided to NHDES in a law that became effective on Sept. 8, which authorized the department to require controls for air emissions of certain PFAS compounds that impact soil and water,’ NHDES said in a statement released Monday.

The investigation, according to the release, concluded that the Saint-Gobain facility continues to have small emissions of PFAS compounds, which could be contributing to the existing groundwater issues. Currently, there are areas surrounding the plant that have detected more than 70 parts per trillion of perfluorooctanoic acid in the groundwater…

In 2016, a few months after PFOA was discovered at two faucets at Saint-Gobain, the plant made improvements to one of its smokestacks in an effort to decrease the amount of residual contaminants being emitted.

And, earlier this year, Saint-Gobain began piloting a treatment system for its air emissions at the facility, which was also designed to determine whether next-generation compounds were exiting through the plant’s smokestacks.

‘Several PFAS compounds were detected in all nine of the stack residue samples collected,’ Robert R. Scott, commissioner of NHDES, wrote in a Sept. 26 letter to Saint-Gobain.

According to Scott’s letter to Edward Canning, director of environmental health and safety at Saint-Gobain, dust samples were also collected from multiple window sills at the Webster Green condominium complex across the street from Saint-Gobain. Those samples detected total concentrations of PFAS at 68.8 parts per trillion, which is just shy of the 70 ppt standard.

More details, including a full overview of the stack testing, will be discussed at a public informational meeting next week in Merrimack.

The new notice given to Saint-Gobain orders the company to submit to NHDES an application for a permit to install air pollution controls within six months.”