PFAS (per-and polyfluoroalkyl substances), a group of more than 4,700 fully synthetic compounds that are widely used in industrial and manufacturing processes and found in many consumer products, persist through wastewater treatment at levels that may impact the long-term feasibility of “beneficial reuse of treated wastewater,” according to a study conducted by researchers and recently published in the Journal of Environmental Quality.

PFAS, often referred to as “forever chemicals,” are used to make fluoropolymer coatings and products that resist heat, oil, stains, grease and water, and are found in a variety of products from clothing and furniture to food packaging and non-stick cooking surfaces.

“PFAS are so pervasive and persistent that they have been found in the environment all over the world, even in remote locations,” said Heather Preisendanz, associate professor of agricultural and biological engineering at Penn State. “Unfortunately, these compounds have been shown to negatively impact ecological and human health, particularly because they can bioaccumulate up the food chain and affect development in children, increase risk of cancer, contribute to elevated cholesterol levels, interfere with women’s fertility and weaken immune systems.”

Because of their wide variety of uses, PFAS enter wastewater treatment plants from both household and industrial sources, said Preisendanz.

Beneficial reuse of treated wastewater is an increasingly common practice in which treated wastewater is used for irrigation and other non-potable purposes. According to Preisendanz, this practice provides an opportunity for the soil to act as an additional filter for PFAS, reducing the immediate impact of direct discharge of PFAS to surface water, as would typically happen following traditional wastewater treatment. However, given that the chemical structures of PFAS are difficult to degrade, the risks and potential tradeoffs of using treated wastewater for irrigation practices, especially in the long-term, are not well understood.

Preisendanz continued, “Our study results have important implications to ensure that beneficial wastewater reuse activities achieve desired goals to reuse water and nutrients, while simultaneously ensuring PFAS levels are safe from a human health perspective.”

The full research paper from the Journal of Environmental Quality can be found here.