On July 6, 2023, CNN reported on a recent US Geological (USGS) Survey study that found almost half of tap water in the United States is contaminated by per-and polyfluoroalkyl substances (PFAS).   USGS scientists indicated that the study might actually underestimate the nation’s water contamination problem, because the agency analyzed water for just 32 of the over 12,000 known PFAS.

The USGS study is the most comprehensive analysis to date of PFAS in the nation’s water supply.

From 2016-2021, USGS analyzed water  from 716 sites across the country (269 private wells and 447 public  drinking water supplies).  The agency found 17 different PFAS in water.  Water with PFAS had between 1-9 PFAS, with a median of 2 PFAS in each drinking water sample.  Concentrations of PFAS ranged from

CNN interviewed Notre Dame physics and chemistry professor Graham Peaslee, an expert on PFAS testing, about the study.  Peaslee said,

“I think that we should try our best to work on how to clean this up. My fear is that this is, global warming aside, this is probably the most expensive environmental problem we’re ever going to face. ”

He added, “There’s nothing that will magically fix it…But the cleanup will have to be done, he said, because these chemicals carry real health consequences and people can’t exactly avoid drinking water…

“It’s really insidious, this poison. We are going to have to get inventive on how to filter it out for all of our days.”

Read CNN’s report on the USGS study.