After nitrate lawsuit, Minnesota opens farm fertilizer rule for public comment

Minnesota is still trying to address farm pollution adding too many nitrates to waterways. Now, prompted by a lawsuit, state agriculture officials want feedback on existing crop fertilizer standards, with the possibility of tightening them.

The state’s Department of Agriculture this month opened public comment on its 2019 groundwater protection rule, a standard that governs how and when commercial fertilizer is applied.

It’s the first step in the Minnesota Department of Agriculture’s review of the standard per a Ramsey County District Court judge’s ruling last fall in a lawsuit by environmental groups holding Minnesota to its 2024 promise to address nitrates in southeast Minnesota waterways.

Environmentalists say more drastic action is needed to make more progress toward cleaner waterways, after a groundwater rule established in 2019.

“It’s been in place for six years now and we’ve seen that it is not making widespread and meaningful reductions in the amount of nitrate that is in groundwater,” said Joy Anderson, lead attorney for the Minnesota Center for Environmental Advocacy (MCEA), which is spearheading the lawsuit on behalf of other environmental groups and rural residents in southeast Minnesota.

Ongoing research links adverse health effects to drinking water with even lower levels of nitrate than the current 10-milligram standard. Associated conditions include colorectal cancer, thyroid disease and neural tube defects.

The MCEA and other water advocates want more stringent fertilizer restrictions, potentially tying application to rates recommended by the University of Minnesota Extension Service. Anderson argues state officials set the groundwater rule too loosely in 2019. The MCEA would also like farmers to keep better track of how much fertilizer they use.

While it will take decades to reverse nitrate levels in water, Birr said the state needs to give more time to farmers to allow current rules to be fully implemented.

“We’re not looking for slack in the rules, but … we can’t keep having the goal posts move on us constantly as that’s really challenging,” Birr said.

Birr and Minnesota Farm Bureau President Dan Glessing point to continually updated research on the best ways farmers can apply fertilizer to increase their yields as proof that ag interests are looking into better pollution control. With evolving technology, farmers are able to get more crops with less fertilizer.

“We’re always learning, we’re always doing more research and finding ways … to have the results we really would like to see,” Glessing said.

Environmentalists counter that that work isn’t resulting in meaningful nitrate reductions.

Advocates approached the EPA in 2023 with concerns Minnesota wasn’t doing enough to enforce nitrate standards. The EPA urged the state to take action to protect people whose well water is polluted, stopping short of an official order.

State officials have measured nitrate water pollution since 1990. Nitrate levels largely have risen across the state since then. Although cities and towns have wastewater treatment plants to address pollutants in their water, private well owners aren’t regulated.