WASHINGTON – Drinking water is so contaminated with farm chemicals in parts of southeast Minnesota that state agencies must take action, the federal government ordered. The state has 30 days to develop a plan. Excessive contamination in well water had been reported to the U.S. Environmental Protection Administration in Winona County and seven other largely agricultural counties. The EPA estimated that 9,000 people in these counties are at risk of consuming water exceeding what’s considered safe — 10 milligrams of nitrates per liter. These counties all have porous underground limestone formations that suck up nitrates from factory-scale farming:
Dodge (population 20,900)
Fillmore (21,200)
Goodhue (47,900)
Houston (18,700)
Mower (40,200)
Olmsted (163,400)
Wabasha (21,500)
Winona (49,600)
Nitrates are invisible, tasteless and odorless – and potentially deadly. These diseases can result:
> Methemoglobinemia.
> Anemia.
> Cardiovascular disease.
> Lung disease.
> Sepsis.
> Glucose-6-phosphate-dehydrogenase deficiency.
> Metabolic problems.
Babies are especially vulnerable. Infant symptoms include bluish skin followed, if untreated, by serious illness and death.
Complainants
Several organizations petitioned the U.S. Environmental Protection Administration to tackle southeast Minnesota ground water issues under the 1948 Clean Water Act. The law has been enhanced several times, most recently in 990, as water toxicity has grown as a problem. The petitioners, whose concerns had been largely ignored by state agencies for years:
> Izaak Walton League.
> Land Stewardship Project.
> Minnesota Center for Environmental Advocacy.
> Minnesota Trout Unlimited.
> Minnesota Well Owners Organization.
The EPA responded under the authority of the U.S. Clean water Act. This was the same route that the EPA used in in 2014 for lead poisoning in Flint, Michigan.
Nitrate sources
High levels of nitrate in agricultural areas result from runoff or leakage from animal feedlots and commercially fertilized soil.
Nitrate remedies
Technology is available to remove nitrates in drinking water. These are complicated:
>Ion exchange.
> Reverse osmosis.
> electrodialysis.
Ion exchange resins are like tiny magnets that attract and hold the nitrate from passing through a water treatment system. Boiling is not a remedy. In fact, boiling increases nitrate levels by evaporate water but no nitrates. Filters such as those in a Brita brand water pitchers don’t remove nitrates. Other remedies go to the source:
> Tighter restrictions n feedlots that produce massive concentration of nitrate in manure.
> Limits on artificial crop fertilizers that are heavy with nitrates that leach into ground water.
Local water systems
The Winona municipal water system wells are deep into an aquifer not affected by high nitrate levels. However, rural wells at higher elevations in Winona County are vulnerable. Heavily contaminated are city wells in Lewiston and Utica. In a state study, 7% of participating private wells in Winona County exceeded the federal health standard for nitrate. In Fremont Township south of St. Charles, 43% of wells tested exceeded the limit. Elevation as a kay:
> Winona: 689 feet above sea level.
> Lewiston: 745 feet.
> Utica: 1,171 feet.
> Fremont township: 1,188 feet.