The U.S. Supreme Court has upheld a permit issued under the Clean Water Act by the Army Corps of Engineers that allows mining waste to be dumped into Lower Slate Lake, north of Juneau, Alaska, according to this article in the NYT. Environmental groups opposed the permit because it might turn the lake "into a lifeless waste dump."
A copy of the decision can be found here (Coeur Alaska, Inc. v. Southeast Alaska Conservation Council).