A mining company and the state of Alaska had asked the justices to take the case. At issue is a challenge by environmentalists to the planned dumping of tailings from gold mining into 23-acre Lower Slate Lake in the Tongass National Forest.

The U.S. Army Corps of Engineers issued a permit for the dumping after the corps and the Environmental Protection Agency agreed to a regulatory change in 2002. The rule defines “fill” as “tailings or similar mining-related materials.”

The 9th U.S. Circuit Court of Appeals in San Francisco invalidated the permit, saying the dumping is barred by stringent EPA pollution-control requirements under the Clean Water Act of 1972.

Dumping the tailings would kill all the fish and nearly all acquatic life and deposit potentially hazardous materials including aluminum, copper, lead and mercury, the appeals court said.

It has been illegal since 1982 for new gold mines using a particular mining process to discharge waste into lakes or rivers. The corps permit would allow the discharge.

The corps has often issued permits in situations that create tailing ponds. Environmentalists say the current permit is the first to authorize the discharge of mining process wastewater into a navigable waterway.

The case is Coeur Alaska Inc. v. Southeast Alaska Conservation Council, 07-984; State of Alaska v. SACC, 07-990.

source : AP