‘Forever Chemicals’ Found in Crystal Lake Fish
State officials proposed adding a several of Minnesota’s bodies of water to its 2024 impaired waters list due to perfluorooctane sulfonic acid (PFOS) contamination. One of those is Crystal Lake in Robbinsdale.
Tracking water contamination is a year-round effort in the land of ten thousand lakes. Leya Charles is a water assessment and impaired waters list coordinator with the Minnesota Pollution Control Agency. A big part of her job is putting together this data.
“Minnesota does monitor more often and in more places than many of the states around us,” Charles said. “We are out there looking for a lot of the pollutants that are out there, and being transparent and putting those on the impaired waters list.”
PFOS chemicals have been used in some consumer products such as stain-resistant clothes, food packaging and firefighting foam.
PFOS are also known as “forever chemicals.”
A Minnesota Department of Health fact sheet says PFOS production has been phased out in America, but production continues in other countries.
Human exposure to PFOS can cause a number of health issues, including reduced immune response and liver function changes.
Why Crystal Lake?
Scientists found PFOS contamination in Crystal Lake’s fish population. Specifically, PFOS was discovered in fish tissue.
“It is above our water quality criteria for what we would consider safe for human consumption,” Charles said.
The department has a page on its website dedicated to fish consumption, with a section on PFOS. Recommendations depend on a number of factors.
“You might have to limit your fish consumption from that, but check the department of health,” said Summer Streets, a research scientist with the MPCA.
Streets suspects the contamination likely came from firefighting foam. Because it was found in fish tissue, she said it isn’t likely to stick around.
“PFOS, anyway, happens to have a very short half-life in fish — that is the amount of time it takes for the fish to get rid of half of their load of PFOS,” Streets explained.
According to Streets, the contamination will likely cycle out of the Crystal Lake fish in two years. In the meantime, the lake’s waters are still good to use for other purposes.
“It is important to remember those uses,” Charles added. “Just because it is impaired for aquatic consumption doesn’t mean it is impaired for aquatic recreation.”
Both Charles and Streets said the lake is still clear for boating and catch-and-release fishing.
This year’s impaired waters list is still in the draft period. The MPCA will take public comment through Jan. 12, 2024.
The full list of impaired waters and a location to share public comment is available on the MPCA website.