This photo shows the portal to the Eagle Mine in western Marquette County, Mich., which Gov. Mark Dayton toured last month. (The Minnesota Star Tribune)

Dear Gov. Mark Dayton,

When we learned you'd be touring the Eagle Mine in Michigan's wild Upper Peninsula, we — board and advisory board members of the grass-roots environmental group Save the Wild U.P. — asked to meet with you, to share key concerns about the mine. We'd like you to make an informed decision on Minnesota's proposed PolyMet project. Since you were unable to meet with us, we're now sharing our concerns publicly.

You toured Eagle Mine's facility, which the sulfide mining industry deems an environmentally responsible sulfide mine. Did you happen to notice the new heavy-duty paved haul road you traveled on from Big Bay — pavement that ends at the gates of the mine? Under Michigan's Part 632 legislation governing sulfide mining, that road should have been regulated as a mining haul road, subject to an environmental-impact assessment and permit revisions. Through a series of political and corporate sleights of hand, the road was paid for by Eagle but built as a county road.

Did Eagle show you its air pollution? For example, did Eagle proudly show you the main vent air raise on the bank of the Salmon Trout River, a wild, blue-ribbon trout stream flowing swiftly down to Lake Superior? During the mine's permitting phase, Eagle pledged to use environmentally responsible bag-house filters to remove heavy metals, sulfide rock particles, exhaust from underground equipment and cancer-causing particulates ejected from the mine following blasting. Did Eagle mention that it changed the design, revised the permit and removed all filters? Now, twice daily, the underground sulfide orebody is blasted and a plume of heavy metals is blown from the stack at high velocity. The pollutants are carried on the wind, falling out over the surrounding environment. Only one stack test was ever done, more than a year ago, prior to the mine becoming fully operational. Twice daily, we are told, someone stands at the vent site and views the plume to rate how dark it is, a sort of visual opacity test — although one blast takes place at night. The actual contents of Eagle's air pollution plume remain entirely unassessed and unregulated.

Did Eagle show you the Salmon Trout, a pristine, groundwater-fed river? At the mine's treated wastewater infiltration system, deionized wastewater is returned to the shallow groundwater aquifer, where it bonds with metals in the ground as it percolates. Almost immediately, it is outside of Eagle's fence line. Did Eagle officials explain that they are using groundwater as if it were a sewer pipe, conveying wastewater directly to springs that feed the east branch of the Salmon Trout?

We'd like you to understand that the Michigan Department of Environmental Quality and the U.S. Environmental Protection Agency (EPA) have allowed Eagle to use the wrong permit, a groundwater discharge permit that meets only human drinking-water values, rather than a National Pollutant Discharge Elimination System (NPDES) Clean Water Act permit, with the more sensitive pollution limits for copper and other contaminants needed to protect macroinvertebrates and other stream life, including trout. We hope you learned that there are no monitoring wells tracking the movement of Eagle's wastewater toward these critical springs. The Salmon Trout will be harmed; it's simply a question of when.

Eagle's milling facility, the Humboldt Mill, also poses multiple threats to clean water, with discharges from its tailings degrading the Escanaba River watershed and the Lake Michigan basin. Note that parent company Lundin Mining Corp. provided a mere $23.2 million in total financial assurances for both the mine ($18 million) and the mill ($5.2 million) — a tiny sum, inadequate to fund even an EPA cleanup investigation.

The sulfide mining industry would like you to ignore these serious issues — impacts to the air, water and land, as well as grossly inadequate bonding assurances — while falsely portraying the Eagle Mine as environmentally protective. The Eagle Mine should be viewed as a dire warning, rather than a good example. We urge you to deny the PolyMet permit and protect Minnesota's most valuable natural resource: clean water.

Kathleen Heideman is president of Save the Wild U.P. in Marquette, Mich.