GMU Helps Monitor PFAS, Heavy Metals, More Pollutants In Potomac After Huge Sewage Spill

FAIRFAX, VA — George Mason University researchers are studying the environmental fallout from a massive sewage spill that sent more than 240 million gallons of wastewater into the Potomac River earlier this year.

Seven George Mason researchers received a nearly $300,000 National Science Foundation grant this summer to investigate how the spill may have affected water quality, aquatic life and the overall health of the Potomac's tidal freshwater ecosystem, the university announced in a recent release.

The spill began after a sewer line collapsed in Montgomery County, Maryland, on Jan. 19. A temporary repair was completed in March, and remediation work has continued.

Researchers at George Mason's Potomac Environmental Research and Education Center, or PEREC, began collecting samples in February with seed funding from the university's College of Science.

"We have 11 different sampling locations where we sample water quality and organisms each month," Amy Fowler, a George Mason associate professor and interim director of PEREC who is co-leading the research, said in a release from the university.

The project has an unusual advantage: PEREC has collected water samples from Gunston Cove since 1984. Researchers can compare conditions following the spill with more than four decades of historical data.

The team is monitoring temperature, salinity, water clarity and nutrients, as well as contaminants including PFAS and heavy metals.

Researchers are also using environmental DNA, or eDNA, to identify organisms from genetic material they leave behind in the water. That allows scientists to track changes in biodiversity ranging from phytoplankton to fish without having to directly capture or observe every species.

"Typically, if you have big, severe, acute disturbances like this, you'll expect to see reductions in diversity," said Jennifer Salerno, a George Mason associate professor who is co-leading the project, according to the release. "So, we're going to test that theory, as well as examine if those changes affect the food web."

The $299,886 NSF grant runs through May 2027. George Mason's regular monitoring of Gunston Cove, funded by Fairfax County, will continue after the grant ends.

The project's findings will be incorporated into the Meaningful Watershed Educational Experiences program with Fairfax County Public Schools. More than 10 graduate, undergraduate and high school students have also been recruited to work on sampling, laboratory analysis, data interpretation and science communication.

George Mason researchers are working with partners including the Potomac Riverkeeper Network and Smithsonian Environmental Research Center on sampling along the river.

Researchers said the work could help determine how a major sewage spill affects the Potomac beyond the immediate contamination and potentially inform how organizations respond to similar incidents in the future.