Research at the Tap: Community Partnerships and PFAS

Public supply and private supply drinking-water can all be routes of human exposure to multiple chemicals and chemical mixtures. Drinking-water exposures to per- and poly-fluoroalkyl substances (PFAS) are a current national concern, however, there is limited information on PFAS occurrence in residential tapwater, especially from private-wells. This data disparity undermines risk-management decision-making, leading to an increased probability of contaminant exposures in rural and remote locations that heavily rely on private wells. We (CPHEA, USGS and others) have conducted research over the last several years to identify and compare PFAS exposures in private-well and public-supply tapwater. In a national reconnaissance study, seventeen PFAS were observed at least once with PFBS, PFHxS and PFOA observed most frequently in approximately 15% of the samples. Across the US, PFAS profiles and estimated median cumulative concentrations were similar among private wells and public supply tapwater. Potential source and land-use information was related to cumulative PFAS concentrations, and the number of PFAS detected.

Impact/Purpose

The results indicate that human-health risks from contaminant exposures are common to and comparable in all three drinking water (DW) supplies.  Importantly, these studies' target analytical coverage, which exceeds that currently feasible for water purveyors or homeowners, nevertheless is a substantial underestimation of the full breadth of contaminant mixtures in the environment and potentially present in DW. Thus, the results emphasize the need for improved understanding of the adverse human-health implications of long-term exposures to low level inorganic /organic contaminant mixtures across all three distribution pipelines and do not support commercial messaging of BW as a systematically safer alternative to public-TW. Regardless of the supply, increased engagement in source-water protection and drinking-water treatment, including consumer point of use treatment, is necessary to reduce risks associated with long-term DW contaminant exposures, especially in vulnerable populations, and to reduce environmental waste and plastics contamination.

Citation

Smalling, K., E. Medlock Kakaley, AND P. Bradley. Research at the Tap: Community Partnerships and PFAS. EPA Bimonthly PFAS Science Call with States & Tribes, Durham, NC, June 24, 2024.