By Peter Chawaga
A new study has underscored the complexity of treating per- and polyfluoroalkyl substances (PFAS), one of the country’s most prolific and widespread water contaminants, while highlighting the futility in attempting to address the problem at wastewater treatment facilities.
“PFAS compounds … are found in greater quantities in the treated water leaving Michigan wastewater treatment plants — the water returning to streams, rivers and lakes — than in the not-yet-treated water entering the plant, a new Western Michigan University study found,” according to the Detroit Free Press. “Detailed study of 10 wastewater treatment plants in Michigan with industrial pretreatment programs — efforts to remove PFAS compounds from their industrial sources before the water reaches the plant — found PFAS concentrations as much as 19 times higher in the plant’s effluent, or outflow, than its influent.”
PFAS — also known as “forever” chemicals due to their lasting impact on the environment — have been linked to adverse health effects in those who consume them via drinking water. They often find their way into water supplies as the result of industrial pollution, and the U.S. EPA has recently announced plans to propose its first-ever rules to limit their presence in effluent.
But many individual states, including Michigan, have already taken action to implement stricter PFAS limits. As this recent study highlights, these regulatory limits may not be enough to curb their presence.
“Michigan currently has some of the strictest drinking water and groundwater standards in the nation,” per Michigan Radio. “The state’s clean-up criteria are 8 parts per trillion for PFOA (perfluorooctanoic acid) and 16 parts per trillion for PFOS (perflurooctane sulfonic acid).”
For Michigan’s wastewater treatment plants, as with similar facilities around the country, the problem seems to lie in the complexity of the PFAS compounds themselves and the challenges ahead in learning how to combat them at the drinking water or wastewater treatment levels.
“It appears that PFAS chemicals that scientists cannot readily detect in the wastewater entering plants are being transformed into detectable PFAS compounds during the treatment process,” the Free Press reported. “PFOS also tends to adhere to sewer sludge, which wastewater treatment plants often convert to biosolids fertilizers and market for use on farm fields.”
As wastewater systems across the country continue to face PFAS in influent, and likely also face stricter regulations around their presence in the near future, they will be hoping for innovation in the tools used to detect and eliminate them as well.
To read more about how wastewater treatment operations address PFAS, visit Water Online’s Wastewater Contaminant Removal Solutions Center.