DEQ releases data from preliminary study of PFAS in biosolids, wastewater

The North Carolina Department of Environmental Quality’s Division of Water Resource (DWR) has released data from a preliminary study that found per- and polyfluoroalkyl substances (PFAS) present in soil, wastewater and biosolids, the nutrient-rich organic material after wastewater has been treated. The study is the agency’s first investigation assessing PFAS concentrations in biosolids across the state.

PFAS are a group of man-made chemicals widely found in commercial, industrial and consumer products. PFAS are known as “forever chemicals” because they don’t break down in the environment and can build up in humans and animals. Wastewater treatment plants can receive PFAS from residential, commercial and, industrial sources. An estimated 3.5 million North Carolinians drink tap water that has PFAS levels above the U.S. Environmental Protection Agency health-based standard scheduled to go into effect in 2029. The deadline may be extended to 2031, according to an announcement by the agency. More information about PFAS can be found on DEQ’s website.

DWR staff began gathering samples in 2023 for the study, which evaluated PFAS concentrations in wastewater and biosolids from 37 municipal, industrial and domestic wastewater treatment facilities. Staff also tested soil collected from 19 fields that are regulated under non-discharge permits.

The study found PFAS compounds present in wastewater, biosolids and soil samples. Estimates found the majority of PFAS entering wastewater facilities on an annual basis is discharged into waterways, as compared with the amount entering the environment through land application of biosolids. An overview of the study, including background information and a summary of the results, is available online.

“The study represents a first step for DEQ to begin to understand PFAS concentrations in wastewater and biosolids in our state,” said Julie Grzyb, deputy director of the DEQ Division of Water Resources. “The study was based on a small sample size and was limited in scope, but it underscores the importance of characterizing and controlling PFAS contamination at the source.”

There are currently no federal or North Carolina state regulatory requirements for PFAS in biosolids. The study will inform future study design and identify opportunities for further data collection and analysis. Researching the movement of these chemicals in the environment was beyond the scope of the study.