MPCA to test entirety of Mississippi River this year • Minnesota Reformer

The Minnesota Pollution Control Agency will be testing water quality along the entirety of the Mississippi River within the state’s borders in 2024, the agency announced this week.

The MPCA typically only tests portions of the river in any given year, and this year’s effort to sample over 50 locations from Bemidji to the Iowa border represents a first for the agency in what could be read as increasing concern about emerging threats to water quality, including 3M-manufactured chemical compounds known as PFAS.  

Water quality within Minnesota’s stretch of the river has improved dramatically over the past four decades, according to a fact sheet from the Metropolitan Council. But levels of some contaminants — including nitrogen from excessive fertilizer use and chloride from road salt — are rising.

“By monitoring our lakes and rivers, we are supporting safe drinking water, enjoyable recreation, tourism, and Minnesota’s strong economy,” said MPCA Commissioner Katrina Kessler. “Our work protecting the mighty Mississippi from its headwaters here in Minnesota is critical to maintaining a healthy river downstream, all the way to the Gulf of Mexico.”

The data will include traditional water quality measurements like temperature, transparency and pollutant levels. Crews will also collect and measure samples of fish and invertebrate life from the river.

The MPCA will also be screening for PFAS contamination for the first time, following the imposition of strict federal limits on the compounds.

In the metropolitan area, Mississippi River water quality degrades downstream of the junction with the Minnesota River, which carries large amounts of agricultural runoff. But it improves downstream of the St. Croix River, which is surrounded by undeveloped areas.

Farm runoff from Minnesota and other Midwestern states contribute to a massive “dead zone” stretching of thousands miles around the Mississippi delta in the Gulf of Mexico. Chemicals in fertilizer fuel massive blooms of algae, which rapidly deplete oxygen levels, making the area unsuitable for many forms of marine life.

Closer to home, nearly the entirety of the river within Minnesota boundaries is on the state’s impaired waters list. Impairments include high levels of fecal bacteria, mercury and polychlorinated biphenyls (PCBs) in fish, PFAS, aluminum and sulfates.