Tolkkinen: Minnesota needs to do a better job protecting well water from farm runoff

Minnesota farmers deserve a lot of credit. Up all hours during calving, out at 20 below to milk cows, and usually working another job, besides.

They raise the sweet corn we eat in late summer, the potatoes that become our French fries, the turkeys that grace our Thanksgiving tables.

But there’s one thing too many farmers do that imperils the drinking water of Minnesotans who live in farm country, especially in areas with fragile soil: They spread too much fertilizer.

Farmers don’t like to hear that, but it’s true, especially in today’s world of 10,000-cow dairies that produce about 1.2 million pounds of manure each day. It has to go somewhere, and hauling it is expensive, so it gets spread on nearby fields.

Some manure spreading is useful. But it becomes a problem when too much of it goes onto a field, or when it gets spread at the wrong time of year. Spread it in the fall, and the nitrogen, a slippery substance that quickly slides into the groundwater, will be gone by planting time in the spring. Spread it on icy fields, and it will all run into drainage ditches and creeks, polluting waterways and lakes, when the ice melts.

Rural Minnesotans who get their water from community wells are generally protected from nitrate pollution, because the state tries to limit the kind of fertilizer-intensive crops like corn that are grown near the wellheads.

But the 1.2 million of us Minnesotans who rely on private wells don’t have that protection. This is especially troubling in farm country, particularly in the central sands area around Stearns County or in the karst region of southeastern Minnesota. If we don’t test our drinking water, we — and our children and grandchildren — might be drinking unsafe amounts of nitrates.

Nitrates in high amounts can be fatal for infants. But nitrates are also possible causes of colon, kidney and stomach cancers.

This week, Minnesota environmental groups sued the Minnesota Pollution Control Agency and the Minnesota Department of Agriculture, contending that the state needs to do more to control the amount of nitrogen in drinking water.

They sued for a couple of reasons. Until Jan. 20, they had the U.S. Environmental Protection Agency on their side. The EPA was nudging Minnesota to protect people from nitrates, so the state allocated about $16 million in 2024 to supply reverse osmosis filters in southeastern Minnesota, to further refine best practices for fertilizer use, and some other things that incrementally protected the health of well users.

But given President Donald Trump’s stated goal of reducing environmental protections, they expected the EPA would no longer be their champion, so they turned to the courts.

Some 35 years ago, Minnesota lawmakers passed the Groundwater Protection Act, which instructs the state to protect groundwater. But the state has been largely relying on polluters — which are primarily farms — to voluntarily comply with clean water rules.

That means the state has chosen not to use the heavier handed method of regulation, said Joy Anderson, the supervising attorney for the Minnesota Center for Environmental Advocacy, who drafted the lawsuit.

“And it hasn’t been working,” she said. “The agencies have admitted over and over again that the current practices and that the best management practices are not sufficient.”

The environmental groups are asking the court to require the state to open up their water protection rules to public comment.

That might sound like tedious bureaucrat speak, but rulemaking is a powerful tool that can result in major changes. Everybody gets to comment on the changes they’d like to see — and that means every Minnesotan — and the state has to respond to every comment. Do you want to preserve the status quo? You can tell them that. Do you want dairies to have to spread their manure in a much larger area? You can say that. Do you want to limit the use of fertilizer in geologically sensitive areas? Go ahead. Let them know.

If the environmental groups succeed in forcing the state to reopen its nitrate standard rules, we could see a huge improvement in the health of our drinking water.

At a time when cancer rates are rising, especially among young people in rich countries, we need to seriously consider what we’re putting into our drinking water. And it’s not only nitrates — it’s medications, PFAs, microplastics, and many other contaminants. But nitrates is a good first step.

“We’re not asking for anything crazy,” Anderson said. “We’re not asking for, you know, people to stop farming. We’re asking farmers to think about not only what they’re putting on their fields, but how that affects the groundwater that their entire community depends on.”

The farmers I know care about their communities a great deal. They might need funding and technical help, though, to meet any new requirements.

Karen Tolkkinen is a Star Tribune columnist focused on the people and issues of greater Minnesota. karen.tolkkinen@startribune.com