It's hard to persuade residents of a state whose very name bespeaks an abundance of water to worry about water quality. Maybe that's why three successive governors did little to implement a 1989 statute empowering state agencies to "promote best practices … to the extent practicable" to minimize groundwater pollution.

Then again, Govs. Arne Carlson, Jesse Ventura and Tim Pawlenty were in office before Minnesotans knew the extent to which nitrate is contaminating groundwater, the drinking water source for 75 percent of Minnesotans. Nitrate causes a potentially fatal condition in infants and is a suspected source of other health disorders.

The bigger worry in 1989 was pesticide pollution. Only since enactment of the Legacy Amendment in 2008 was funding available for tests that found that dozens of community water systems and, in a southeastern Minnesota sample, one in 10 private wells contained potentially unsafe nitrate levels. Although nitrate is a naturally occurring substance, elevated levels in water have been linked to farmers' use of fertilizer to boost production of this state's two big cash crops, corn and soybeans.

Unlike his predecessors, DFL Gov. Mark Dayton is not spared that knowledge, and he's trying to do something about it. Last week, Dayton and state agriculture Commissioner Dave Frederickson unveiled an amended version of a proposed rule on agricultural fertilizer use in areas with porous soil and/or high nitrate levels in public drinking water.

In those targeted areas, the proposed rule would restrict fertilizer use in the autumn, in keeping with best practices recommended by the University of Minnesota. Fertilizer applied in the autumn is most likely to leach into groundwater or wash into streams and rivers rather than stay in the topsoil to be absorbed by young plants in the next growing season. That's especially true where soils are porous and/or annual precipitation is high.

The proposed new rule would rely on local advisory teams and a phased series of voluntary and mandatory practices to address high nitrate concentrations. "No one will be told 'You can't grow corn,' " Frederickson assured a state Senate panel.

Nevertheless, the amended rule is bound to face some of the same resistance its original version faced last year. Republican legislators made that clear. "My farmers feel like they've been kicked around" by the Dayton administration, state Sen. Michael Goggin, R-Red Wing, told Frederickson, referring to Dayton's push to ban row crop production in buffer strips adjacent to public waterways.

Two House committee chairmen, Rod Hamilton of Mountain Lake and Paul Anderson of Starbuck, issued a joint statement calling Dayton's effort "a reactionary re-branding of a vastly unpopular rule." They urged the governor to drop the rule-making effort and "work with us through the legislative process to ensure maximum participation and input from farmers and other stakeholders."

We can echo part of that call. As the rule-making process enters a new public comment phase, those comments ought to include legislative hearings. The proposed rule is subject to more months of public input before at least one more revision; it is expected to be finalized by December. That's ample time for legislators to weigh in. But the 1989 Legislature was right to give a state agency the authority to take practical steps to keep Minnesota's drinking water safe. That authority should stand. The Legislature is ill-suited to do this work on its own.

The state Senate sponsor of the 1989 bill, Steve Morse, is today's executive director of the Minnesota Envionmental Partnership. Halting the rule-making now would be "a horrendous setback" at a critical time, Morse aptly said. "It goes to a core question about who we are as Minnesotans, if we will not protect our corpus of clean water." Now would be a fine time for Minnesotans who agree to say as much to their legislators.