Senators Amy Klobuchar and Al Franken should not have publicly endorsed the proposed Polymet copper-nickel mine because of the damage the environmental review is predicting it will cause, according to a letter to the senators from 13 environmental groups.

The groups, including Minnesota Center for Environmental Advocacy, also requested a meeting with the senators to explain their concerns in detail and to explain a proposed state bill to require the mining companies to post a “damage deposit” to clean up any damage to the waters and lands from the mining operation.

“We are writing to express our disappointment in your recent premature endorsement of PolyMet Mining Corp.’s NorthMet mine project,” the letter states. “Our organizations consider this form of mining, which is much different than the iron mining that Minnesota has been home to for more than a century, a significant risk to the state’s finances and environment. We believe these projects need further review before anyone passes judgment.”

The letter further points out the problems already discovered by the draft environmental impact statement for the proposed mine near Hoyt Lakes. Those problems include likely acid runoff into lakes and rivers near the site, an increase in the amount of mercury absorbed by fish which already is a public health problem, criticism from the U.S. Environmental Protection Agency for not including a review of financial assurance or “damage deposits” to clean up future damage, and how to curb the global warming problems from the mine, among others.

Despite these problems identified in the document, few, if any, solutions were examined, the letter states.

The letter, dated Dec. 21, also requests a meeting to discuss those issues and the proposed bill to be introduced in the Minnesota Legislature, which would tighten up the state’s financial assurance laws “to better guarantee that Minnesota taxpayers will not be left on the hook should the mining companies abruptly leave the scene, as they have so many times before, without meeting their legal obligations.”