MINNEAPOLIS (AP) — A federal judge has rejected challenges by several environmental groups to a land swap needed for the planned PolyMet copper-nickel mine in northeastern Minnesota.

U.S. District Judge Joan Ericksen dismissed the four challenges late Monday. She ruled that the groups lacked the necessary legal standing to block the land exchange between PolyMet and the federal government.

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She said that’s because PolyMet had not yet secured all the necessary permits to begin work, so the groups couldn’t establish that they’d been harmed.

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PolyMet traded 6,650 acres of federal land in the Superior National Forest near Babbitt and Hoyt Lakes for a similar amount of private land last year. The environmental groups say the deal undervalued the federal land and violated other laws. PolyMet disputed those claims.

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