Date
Monday, July 28, 2025
Time
1:30 PM - 2:00 PM
Location Name
Ballroom C
Name
Emerging PFAS regulations and solutions for wastewater utilities
Track
Clean Water Emerging Issues
Description
Per- and polyfluoroalkyl substances (PFAS) are a group of compounds that occur throughout the environment and have a wide range of ecological and human health risks. Perfluorooctanoic acid (PFOA) and perfluorooctanoic sulfonate (PFOS), which have been most widely studied, have been linked to kidney and testicular cancer, as well as endocrine disruption and other medical effects in humans. Notably, sources for drinking water, both surface and groundwater, have been reported to be contaminated with legacy and emerging PFAS (Kumarasamy et al., 2020; Mullin et al., 2019; Bach et al., 2017; Zaggia et al., 2016) from urban and industrial discharges (Campo et al., 2016), firefighting foams that leach into water supplies (Daly et al., 2018), urban stormwater (Page et al., 2019), and land application of wastewater biosolids (Rahman et al., 2014). Thus, it is no surprise that the US Environmental Protection Agency (EPA) has been advancing regulations and risk assessments as outlined int the PFAS Action Plan – the first multi-media, multi-program, national research, management, and risk communication plan to address a challenge like PFAS.
EPA has already promulgated PFAS regulations for drinking water, and while early source water surveys in Kentucky and Tennessee reveal fewer issues than in many other states (https://eec.ky.gov/Documents%20for%20URLs/PFAS%20Drinking%20Water%20Report%20Final.pdf; https://www.tn.gov/environment/policy/pfas/tdec-pfas-sampling.html), new draft criteria for ambient water quality and biosolids that may make their way into state water quality rules may have more substantial implications for wastewater utilities throughout Tennessee and Kentucky. Notably, EPA has published draft Human Health Criteria for Ambient Water Quality. These values, some of which stretch down into the femtogram per liter concentrations, could have significant implications on wastewater discharges, particularly for discharges with low dilution factors.
In addition to impacts on future wastewater discharges, EPA has also just published a draft Sewage Sludge Risk Assessment for PFOA and PFOS (January 2025) that indicates that there may be human health risks exceeding the EPA’s acceptable thresholds for some modeled scenarios when land-applying sewage sludge that contains 1 part per billion (ppb) of PFOA or PFOS. And, while EPA recognizes that eliminating these risks is not currently possible, they recommend, in addition to pretreatment to reduce PFAS, that WWTPs leverage options or practices that can mitigate or lessen risks.
This presentation will provide a summary of the draft threshold values for PFAS in ambient water quality and bisolids and compare these values to recently reported results that have been published on wastewater effluent and unstabilized and stabilized wastewater solids. The authors will also present conventional and promising innovative approaches that can be deployed in a programmatic approach to strategically manage PFAS at wastewater plants.