The U.S. Army Corps of Engineers initiated a 30-day public comment period Jan. 14 on a permit application from Teck Cominco Alaska Inc. to increase the size of the tailings compound at its Red Dog zinc-lead mine near Kotzebue.
In the application, Teck Cominco said it needed more holding capacity at the mine to maintain the integrity of the tailings facility, which is an important part of the mine’s waste treatment system.
Specifically, added capacity would raise the crest elevation of the main tailings dam at Red Dog by 10 feet to 970 feet and maintain a 5-foot freeboard needed for safe operation of the waste treatment facility. Fill would be added to the downstream side of the dam, using toe-up construction methods to increase the size and elevation of the dam.
The construction would require about 358,000 cubic yards of clean fill, which would be obtained from a local material site. About 16,000 cubic yards of the fill would be placed in a 1-acre wetlands area along the west side of the dam.
Also, the seepage pond access road and pipe containment ditch at the base of the current dam would be relocated about 100 feet to the north in order to accommodate the increase in the size of the dam. The road and associated pipe bench would affect another 1.7 acres of wetlands.
Comments should be sent to the Army Corps by Feb. 13. For more information, contact Don Kuhle at (907) 753-2780 or toll free within Alaska at 800-478-2712, by fax at 907-753-5567 or by email at firstname.lastname@example.org.