Researchers at the University of New Hampshire say roughly 10 percent of the per- and polyfluoroalkyl chemicals present in Great Bay can be traced back to wastewater facilities.

This was discovered after the researchers conducted two of the first studies in New England to collectively show that PFAS ends up in the environment after being processed through wastewater facilities, making it more challenging to set appropriate screening levels.

Courtesy of UNH
Courtesy of UNH

Paula Mouser, associate professor of civil and environmental engineering, said PFAS chemicals are not easily broken down and have been linked to adverse health effects.

“They are found in a wide variety of industrial, commercial, and medicinal products that can end up in the body, human waste, and the environment,” Mouser said in a statement released by UNH’s media relations department.

The findings suggest other dominant PFAS sources are contributing to the waterway pollution, such as septic systems, agricultural land, urban runoff, groundwater discharge from contaminated sites, and surface water runoff.

For the first study, researchers looked at the journey of 24 different PFAS chemicals as they passed through six New Hampshire wastewater treatment facilities, including those along the Great Bay Estuary on the Seacoast.

The Maine Department of Environmental Protection has established screening levels for three PFAS chemicals in biosolids, so for the second study, researchers used those numbers to examine biosolids from wastewater treatment facilities in New Hampshire and Vermont.

Of the 39 biosolids reviewed in the sludge waste, 29 had PFAS levels that exceeded screening levels set by the Maine DEP.

Courtesy of UNH
Courtesy of UNH

Mouser said state agencies across New England are considering regulating PFAS in wastewater biosolids, but more research is needed on how the treatment of wastewater sludge influences these forever chemicals.

The challenge is finding a safe and acceptable level for waste residue that doesn’t force facilities to deposit these solids in landfills which would be costly, fill up landfills faster than anticipated and possibly lead to the leaching of PFAS into landfill wastewater.

This research was funded by New Hampshire Sea Grant and the UNH Collaborative Research Excellence Initiative.

Contact Managing News Editor Kimberley Haas at

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