MPCA testing the entirety of the Mississippi River within Minnesota

MINNEAPOLIS, Minn. —It winds 650 miles, rushing past the cities, industries and landscapes that make up Minnesota.

However, the Mississippi River has never gotten this type of attention from water quality professionals.

For the first time ever, the Minnesota Pollution Control Agency (MPCA) is testing the entirety of the river, from Itasca to Iowa, in a single year.

The governor’s office wants the river to be swimmable and fishable, but right now, parts of the river are polluted.

The MPCA says the upper Mississippi is largely healthy up north, but quality drops south of St. Cloud where metro development and tributaries from agriculture muddy the waters. The National Park Service says stretches of the river exceed water quality standards for things like mercury, bacteria and sediment.

Think of the testing like a checkup for one of our state’s most valuable and powerful resources. Researchers will check temperature, transparency and levels of pollutants like phosphorus, nitrogen and ammonia.

Crews also check fish for those contaminants and collect insects to test in a lab to identify any concerning trends.

“If we find the fish community is suffering — maybe the water is too warm and maybe there’s a thermal pollution source upstream or maybe it’s too much runoff — that sort of stuff. Temperature is an important indicator especially for sensitive species,” Isaac Martin with the MPCA said.

Also for the first time, the agency is looking for PFAS contamination with money from an Environmental Protection Agency grant to identify and stop the forever chemicals from streaming into the Mississippi.

PFAS are a group of manufactured chemicals for industry and consumer products that don’t break down in the environment. While research is ongoing, the EPA says exposure to the chemicals can cause human health issues. It’s why the federal agency just lowered the amount allowed in drinking water.

“They go to parts per trillion, which is incredibly sensitive. You get that low, you’re talking drops in an Olympic swimming pool,” Martin said. “Part of the reason why it was chosen is because it’s a primary drinking source or potentially could be a primary drinking source. We’re just finding them in places we never expected to find them. We’re finding them almost everywhere and being that it is new, there’s just a lot of ‘I don’t know’ that goes with it.”

It’s too early to know what this complete snapshot will reveal, but we know this powerful river is part of our community, economy and health.

“Maybe you don’t use the resource yourself, but maybe you know someone who does or future generations of your own will,” Martin said. “In Minnesota, we’re just trying to be the best stewards we can be.”

The data from this testing will be available early next year. Researchers will use that data and compare it to 10-year pollution averages to determine which parts of the river are improved or impaired.

A full report will be released in 2026.