Editorials are designed to provide clarity and understanding to public policy. In this regard, "Timely leadership by Smith on BWCA" (April 26) fell far short. The writers enthusiastically applaud U.S. Sen. Tina Smith's letter to the Biden administration expressing opposition to the Twin Metals project on the grounds that it would place the Boundary Waters in jeopardy. We fully agree.

However, at no point does the Star Tribune Editorial Board, or Sen. Smith, mention that all the same hazards endangering the BWCA also are present in the PolyMet mine that threatens the St. Louis River and Lake Superior, which provides drinking water for the Fond du Lac Band of Lake Superior Chippewa and the people of Duluth.

But perhaps the most disturbing element is the editorial's misuse of Walter Mondale's legacy. Clearly, he was one of our nation's finest conservationists and a major player in the establishment of the BWCA.

However, Mondale was also a fierce and outspoken critic of all sulfide mining and not just one project as the Editorial Board clearly implies.

"We have learned much about the catastrophic consequences of sulfide-ore mining," Mondale wrote in a Star Tribune commentary, "Fighting to save the soul of Minnesota" (March 14, 2016). "Above all else, we have learned that sulfide-ore mining has never — never — been undertaken without serious environmental consequences. Sulfide-ore mining is dangerous everywhere and most dangerous in wet environments.

"[The contaminants] will surely outlive all of us and will just as surely outlive the mining company's pledges, promises and sureties."

If we are to truly honor his life's work, we must, once and for all, honestly come forth and acknowledge that both proposed mining projects, Twin Metals and PolyMet, pose the same mining risks and clearly endanger Minnesota's most cherished physical asset, its pristine waters. This state cannot and must not place these waters at risk.

Fortunately, the federal government last week struck out against the gross mismanagement of the PolyMet mine permitting process. That puts the state on notice and will require rethinking and redoing. But, even aside from this action, Minnesota should have the wisdom to listen to Mondale's warning and, at a minimum, conduct a comprehensive and independent water study before even considering placing our precious waters in harm's way.

Arne Carlson was governor of Minnesota, 1991-99. Tom Berkelman (DFL-Duluth, 1977-83) and Janet Entzel (DFL-Minneapolis, 1975-84) were members of the Minnesota House. Chris Knopf is executive director, Friends of the Boundary Waters Wilderness.