Seasonal Analysis of PFAS in Groundwater Wells

Drinking Water
Oral Presentation

Prepared by Y. Li, J. Whitaker
Eurofins Eaton Analytical, LLC, 110 South Hill Street, South Bend, Indiana, 46617, United States

Contact Information: [email protected]; 574-472-5562


Human exposure to per- and polyfluoroalkyl substances (PFAS) is a worldwide public health issue. Drinking water supplies have become increasingly vulnerable to PFAS contamination from industrial discharges, fire-fighting activities, wastewater discharges, landfill leachates, biosolids, air emissions, etc. In the United States, approximately 22 states have had different kinds of drinking water regulations for 11 PFAS. Some regulations are more stringent than the others. In June of 2022, the Environmental Protection Agency (EPA) also published the final health advisory levels for 10 ng/L of HFPO-DA and 2,000 ng/L of PFBS and the interim health advisory levels for 0.004 ng/L of PFOA and 0.02 ng/L of PFOS. The second national drinking water assessment through the fifth Unregulated Contaminant Monitoring Rule (UCMR5) has started to monitor 29 PFAS in approximately 10,311 public water systems (PWS). As anticipated, EPA will soon establish a national primary drinking water regulation at least for PFOA and PFOS. PFAS contamination in groundwater has been widely studied. Some states (e.g., CT, MA, MN, and NY) have provided information about PFAS testing in private wells. According to EPA’s estimates, there are more than 23 million households relying on private wells for drinking water in the United States.

This work will present the seasonal analysis of 54 PFAS in the selected groundwater wells by using a modified EPA Method 533. The studied wells included small transient non-community water systems (TNCWS) and private wells in local suburban areas and were not in proximity to potential sources of PFAS contamination from commercial and industrial operations. The purpose was to assess the occurrence concentrations and seasonal variations of PFAS and the potential impacts of household plumbing on PFAS detection. The results have indicated that 12 out of 54 PFAS were detected at varied concentrations (sub- to low ng/L) in 12 out of 20 groundwater wells, seasonal variations of PFAS concentrations were detected in some wells, and impacts of household plumbing on PFAS results were insignificant. It is our hope that these data can be useful for considering private well water quality and future PFAS regulations.

Presentation Description:
This presentation will describe the seasonal analysis of 54 PFAS in the selected groundwater wells used as a source of drinking water. The results will be helpful for understanding PFAS contamination in the least monitored drinking water wells, potential impacts of household plumbing materials, and occurrence of new PFAS as well.