Read the full article by Chris Hubbuch (Wisconsin State Journal)

“Scientists at UW-Madison are working to better understand how toxic ‘forever chemicals’ move through the ground, which could help communities like Madison find and clean up the manufactured compounds before they contaminate drinking water.

Used for decades in firefighting foam, non-stick cookware and stain-resistant fabrics, these synthetic compounds, known collectively as PFAS, have been linked to health problems including low birth weight, cancer and liver disease.

Sprayed on the ground in firefighter training exercises, leaked from landfills and spread on farm fields in sewage sludge, PFAS, which do not break down naturally, have contaminated communities across the nation and Wisconsin, including Marinette, Wausau, La Crosse and Madison.

But in order to clean up a spill, you have to know where it is.

A new paper published in the journal Environmental Science & Technology presents a simplified framework for understanding how the chemicals are moving through the jumble of soil, sand, rock and water that lie between the surface and deep aquifers that supply drinking water.

That’s especially difficult because air, water and particles are constantly moving through this ‘unsaturated zone,’ said Will Gnesda, a UW-Madison graduate student in geoscience professor Christopher Zahasky’s lab and lead author of the study.

It’s a problem for any contaminant, but the unique properties that attract PFAS to the boundary between air and water make it all the more challenging.

‘Chemistry dictates that part of it wants to be in water and part of it wants to be in air,’ Gnesda said. ‘The unsaturated zone is full of those boundaries.’

The synthetic chemicals, which do not break down naturally, have been linked to health problems including low birth weight, cancer, and liver disease.

Christy Remucal, an associate professor of civil and environmental engineering at UW-Madison who specializes in PFAS but was not part of Gnesda’s study, said the research is a critical first step to being able to focus cleanup efforts.

‘There’s lots of places where they might stick,’ Remucal said. ‘There are over 6,000 different PFAS and they don’t all behave the same way. It’s really challenging, just because it’s so complex.’

Predicting the movement of PFAS has traditionally involved guesswork and a lot of computer models.

Gnesda and his colleagues developed a simplified framework to reduce the time and computing power needed to model the movement.” …