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FOR IMMEDIATE RELEASE
Oct 22, 2013

 

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Jeni Garcin-Flatow
Remediation
406-841-5016

 

McLaren Tailings Reclamation Project in Cooke City Wrapping Up

 

FOR IMMEDIATE RELEASE
October 22, 2013

FOR MORE INFORMATION

Jeni Garcin-Flatow
DEQ Remediation Public Information Officer
406-841-5016
jgarcin2@mt.gov

McLaren Tailings Reclamation Project in Cooke City Wrapping Up

Helena – The Montana Department of Environmental Quality (DEQ) Abandoned Mine Lands (AML) program has completed its fourth construction season at the McLaren Tailings mine reclamation project near Cooke City, Mont. The reclamation work is one year ahead of schedule and is expected to be completed by the fall of 2014.

Several major milestones were achieved during the 2013 construction season, including the removal of mine waste from the Soda Butte Creek floodplain and the return of Soda Butte Creek to its pre-mining channel. The mine waste, which includes waste rock and mine tailings, has been put into an engineered repository where it can be stored safely.

Removing the mine waste from the bottom of the Soda Butte Creek drainage has eliminated the risk of it washing downstream, preventing significant damage to the Soda Butte Creek and Lamar river valleys within Montana and Yellowstone National Park. Stopping the continuous discharges of polluted water to Soda Butte Creek will be a significant factor in restoring the creek to its pre-mining state.

“This cleanup is an excellent example of the work that DEQ does to protect human health and the environment, “says DEQ Director Tracy Stone-Manning. “Soda Butte Creek will now be a healthier fishery and clean water will run into Yellowstone National Park.”

DEQ began work on the McLaren Tailings in June 2010. Approximately 250,000 cubic yards of mine waste have been removed, mixed with lime and placed in the repository. Over 100 million gallons of contaminated water have been pumped from dewatering wells surrounding the area and treated to meet DEQ water quality standards. This has allowed for the safe removal of the mine waste. Approximately 2,000 feet of Soda Butte Creek has been reconstructed in the area that was covered by the mine waste and the creek has been returned to its historical location.

In 2014, the cover soils saved since 2010 will be mixed with compost and spread over the project site and a cap will be completed over the repository and covered with soil. Both will be seeded. Monitoring of water quality in Soda Butte Creek and the revegetation of the site will also be conducted.

For more information on the McLaren Tailings reclamation project, please contact Tom Henderson at 841-5052 or at thenderson@mt.gov or visit the webpage at http://deq.mt.gov/abandonedmines/mclaren.mcpx.

Background
From 1934 until 1953, the McLaren Mill processed gold and copper ore from the New World Mining District. During the operation of the mill, Soda Butte Creek’s channel was filled with mine waste and the stream was diverted into a ditch and culvert that ran along the south side of the impoundment. A flood in 1950 breached the tailings dam and they washed downstream. The tailings have been found fifteen miles downstream near the confluence of Soda Butte Creek and the Lamar River in Yellowstone National Park. In 1969, the tailings impoundment was graded and covered with soil, and Soda Butte Creek was routed into a channel dug along the north side.

Discharges of polluted water from the McLaren Tailings have been identified since the 1960s as a significant source of metals contamination to Soda Butte Creek. Following the Yellowstone fires of 1988, the proximity of the tailings dam to Soda Butte Creek was identified as a significant concern because a high runoff could erode or saturate the dam, causing it to fail. This would have resulted in a catastrophic release of the tailings into the creek. The McLaren Tailings site was designated an Emergency Response Action Site by the U.S. Environmental Protection Agency in 1988, resulting in efforts to stabilize the dam.

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