# Per and Polyfluoroalkyl Substances in Tap Water Following an Accidental Release of Fire-Fighting Foam into the Drinking Water System in McKeesport, Pennsylvania, USA

## TL;DR

A fire in McKeesport led to PFAS contamination in tap water, with some homes still exceeding safety limits even after cleanup efforts.

## Contribution

This study provides empirical evidence of PFAS contamination in household tap water after a fire-fighting foam release.

## Key findings

- Five months after the incident, PFOS levels in 5 out of 15 homes exceeded the EPA's 4 ppt threshold.
- Kitchen taps had the highest PFAS levels, followed by bathroom and laundry taps.
- Point-of-use filters effectively removed specific PFAS, and hydrant flushing reduced contamination system-wide.

## Abstract

On July 16th, 2021,
a fire at an auto body shop in McKeesport,
Pennsylvania, caused firefighting foam containing per and polyfluoroalkyl
substances (PFAS) to enter the drinking water system. Although the
water authority flushed the distribution system, community concerns
persisted about PFAS residues in plumbing and contamination risk at
consumers’ taps. To address this, we collected tap water from
kitchen, bathroom, and laundry sinks in homes during November 2021-
May 2023. Point-of-use filters (POUFs) were provided, and filters
were collected to evaluate their efficacy. Our results showed that
five months after the incident, perfluorooctanesulfonate (PFOS) levels
in 5 out of 15 homes exceeded the USEPA’s drinking water threshold
of 4 ppt. 6:2 fluorotelomer sulfonate was frequently detected in the
tap water. Kitchen taps had the highest PFAS levels, followed by bathroom
and laundry taps. GenX was detected in aerator extracts from 5 homes
but determining its source requires further investigation. POUFs effectively
removed specific PFAS, and hydrant flushing by the local water authority
was successful in decreasing levels across the water system. However,
lack of clear communication following the event left the community
distrustful of their water quality, and community members reported
feeling disconnected from the decision-making process.