The Minnesota Department of Agriculture wants to test 70,000 private wells throughout the state's farming regions as part of an ambitious but controversial plan to measure and fix nitrogen contamination in drinking water.
The initiative reflects urgent concerns about Minnesota's groundwater, which in some areas shows rising levels of pollution from the tons of fertilizer and other forms of nitrogen applied each year across the southern two-thirds of the state. A 2011 survey found that 62 percent of the monitoring wells in central Minnesota, where groundwater is most susceptible, showed excessive contamination.
The plan, which officials hope to complete early next year, also calls for persuading farmers to ratchet up their control of fertilizer. That could mean asking farmers not to fertilize in the fall, when the risk to water is greatest — or, potentially, stronger steps such as requiring farmers to plant different crops or paying them to take land out of production altogether.
Agriculture Department officials say the plan reflects everything they've learned about managing fertilizer since they were assigned responsibility for protecting the state's groundwater a quarter-century ago. So far they have relied on voluntary measures, but now for the first time are inching toward direct regulation when nothing else works.
But environmental advocates, state health officials and at least one influential legislator say the plan is inadequate. They are urging the department to adopt tougher measures to address an increasingly widespread contaminant that can be lethal to infants and harmful to livestock.
The sharpest critics say the new plan perpetuates a failed strategy that relies on trusting that landowners will voluntarily protect water, and that the agency is not fulfilling its charge to protect groundwater that provides drinking water to three-fourths of the state.
"It's more of the same with the public's money," said Rep. Rick Hansen, DFL-South St. Paul. "I don't think that's what the law says and that's not what Minnesotans expect."
First plan surfaced in 1990
The Agriculture Department devised its first fertilizer-management plan in 1990, recognizing that groundwater contamination was becoming a significant problem in central, southwest and southeast Minnesota. Since then, the state, the University of Minnesota and other agronomists have devised increasingly sophisticated practices to minimize nitrogen losses — which farmers largely follow, officials said.