in the early 1970s there was a the Reserve Mining Controvery, centered upon
tailings discharges of taconite (iron) into the lake, near Duluth, MN.
people in the metropolitan and surrounding area mobilized to fight the appar-
ent threat to the people's health.
in the end, they were successful. today, there are undoubtedly people still
living in the area who may help you out on this new threat. if you want, i
can look up some references and names for you to contact.