The elephant in the water-quality room

In his call for a summit to address the "critical" condition of Minnesota's lakes and streams, Gov. Mark Dayton correctly said that surface-water deterioration can no longer be ignored.

While it's fair to say that the action is a few decades late and that the damage already done to our celebrated lakes is much more serious than most realize, at least Dayton is standing up to an enormous and expanding problem that his predecessors flat-out neglected.

It's also noteworthy that Dayton announced the summit before the state's largest agricultural groups — the Farm Bureau and the Farmers Union — where he boldly spoke the truth: "Modern farming practices, especially the use of nitrogen fertilizer," contribute to farm-country lakes being mostly lost.

There's more than farming to blame, of course, like those who overdose lawn fertilizers or root out shoreland vegetation or fail to correct a faulty septic system. There also are local governments that bulldoze and pave and otherwise destroy natural vegetation in near-lake watersheds.

Lakes in farm country are degraded beyond reasonable hope of restoration, and too many highly prized recreational lakes in central Minnesota are stressed to a tipping point. Only the northern and Arrowhead lakes remain in good shape, despite emerging threats like the mass conversion of forested lands to potato farms near Park Rapids.

But pause to ponder an unfortunate recent bit of political pandering by Sen. Al Franken, D-Minn. Responding by e-mail to a Star Tribune reporter on an issue involving federal clean-water rules, Franken said all Minnesotans "support clean lakes, rivers, and streams — including our farmers and ranchers who are good stewards of the land and water."

Perhaps the senator slipped back into his previous life as a comedian and attempted a bad joke.

From the early 1900s to the present, the drainage of tens of thousands of potholes transformed farm country from a bejeweled complex of shimmering wetlands teeming with wildlife to, essentially, a black desert. Meandering streams became straight ditches, sod was busted on erosion-prone slopes and, more recently, nitrogen fertilizers coated fields to produce more yield from crops protected from weeds and bugs by truckloads of pesticides and herbicides.

Wetland destruction took out grasses that filtered excess nutrients along with basins that held spring runoff, recharged ground water, and provided habitat for an array of wildlife, including ducks and pheasants valued by hunters. There's a reason that floods are ever higher and more frequent and that hunters have to traipse ever farther for quarry.

Excessive fertilizers have washed down the Mississippi River from Midwest farmland and formed a 6,000-square-mile dead zone in the Gulf of Mexico. Nitrogen grows crops, but in excess it promotes overgrowth of algae that die and consume oxygen as they decompose, depleting the aquatic-rich gulf — and our lakes — of life support for things that swim. Sometimes the algae is the poisonous blue-green stuff that's killed more than a few thirsty dogs and other critters.

Then there's atrazine, a nasty herbicide widely used on corn. Recent tests in Minnesota showed atrazine levels three times the national standards and even worse during spring run-off. The endocrine-disruptor is banned in Europe, but in the U.S., it's used heavily on crops in southern parts of Minnesota, Wisconsin, and Michigan, much of Nebraska, and nearly all of Iowa, Illinois, and Indiana. In that broad region the long-lived atrazine is the most common toxin found in drinking water.

There's also the tilling of erodible land, which in the 1960s was seen as serious enough for the federal government to create the Conservation Reserve Program to pay farmers to keep environmentally fragile lands out of production.

Earlier this year, Dayton made headway with legislation requiring 50-foot buffer strips around public waterways. Were such a requirement universally applied — as it reasonably could be in a single growing season — there would be major water-quality improvements all across Minnesota.

Predictably, the biggest opposition to Dayton's buffer bill came from Big Ag, the very folks Franken claims are "good stewards of the land and water."