Hoyt Lakes, MN (NNCNOW.com) -- Mesabi Nugget, an iron processing plant near Hoyt Lakes, is at the center of a lawsuit.
The environmental group WaterLegacy filed the lawsuit on Monday.
The group alleges the U.S. Environmental Protection agency violated the Clean Water act when it approved a water quality variance late last year for Mesabi Nugget.
The complaint says the variance improperly allows the plant to discharge excessive levels of salts and other contaminants, which threaten wild rice and other aquatic species in the St. Louis River.
Mesabi Nugget did not immediately respond to a request for comment.
The EPA does not comment on pending litigation.