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August 25, 2023

'Forever chemicals' found in most Pennsylvania streams tested by U.S. Geological Survey scientists

Neshaminy Creek in Bucks County and Valley Creek in Chester County have the highest concentrations of PFAS in the state

The vast majority of Pennsylvania streams sampled four years ago by the U.S. Geological Survey were contaminated with "forever chemicals," according to a study published Friday. 

Researchers collected water samples from 161 streams and rivers in September 2019, and tested them for 33 types of per- and polyfluoroalkyl substances, or PFAS. They found that 76% of sampled streams contained at least one of these so-called "forever chemicals." 

PFAS are a group of 12,000 synthetic chemicals commonly used to make nonstick cookware, waterproof clothing, food packaging, firefighting foam, personal care products and household cleaning items. They also have been found in food, drinking water, and soil and groundwater near landfills. 

Many PFAS break down very slowly and can build up in people, animals and the environment over time, according to the U.S. Environmental Protection Agency. That's why they're been dubbed "forever chemicals." 

High concentrations of some PFAS have been linked to thyroid problems, developmental delays, immune system issues, higher cholesterol levels, decreased fertility, high blood pressure in pregnant people and an increased risk of some cancers. 

The prevalence of PFAS in the environment has made made them a major concern for water quality, according to the U.S. Geological Survey. Though scientists are particularly concerned about the impact of PFAS on drinking water, only untreated surface water — and no drinking water — was tested as part of the 2019 study. 

Still, researchers suggested better water treatment methods are needed to remove potential PFAS contamination from drinking water sourced from Pennsylvania's streams. 

The highest concentrations of PFAS were found in the Philadelphia region, but Neshaminy Creek in Bucks County and Valley Creek in Chester County were the only streams in the state that exceeded the EPA's proposed Hazard Index, which if implemented would enforce PFAS limits in drinking water. 

The contamination in Valley Creek was likely due to wastewater from an electronics manufacturer, researchers said. Contamination at Neshaminy Creek was likely from firefighting foam used at a former joint military base in Horsham, the Delaware Currents reported last year.

Other streams with high concentrations of PFAS included the Schuylkill River in Pottstown and at Falls Bridge in Philadelphia, Perkiomen Creek in Collegeville, Brandywine Creek at Chadds Ford, Wissahickon Creek in Philadelphia and Fort Washington, and Red Clay Creek in Kennett Square, the Inquirer reported.

Electronics manufacturing and water pollution control facilities were the top sources of PFAS contamination in urban waterways, researchers said. Combined sewage overflows located near oil and gas developments were the likely culprits of contamination in rural areas. 

"This is the first statewide study that associates electronics manufacturing as a source of PFAS in streams, which is likely an under-recognized, but significant source of PFAS contamination," said Sara Breitmeyer, a USGS chemist and lead author of the study. "The sources of environmental PFAS contamination are starting to be better understood thanks to studies like this. Our study contributes new information on PFAS sources to surface water in Pennsylvania, which will help regulatory agencies address the growing concerns of PFAS's ecological and human health impacts across the state." 

The most prevalent PFAS chemicals found in Pennsylvania's waterways are consistent with common PFAS detected in surface waters throughout the Northeast, the study found.