McLaren Tailings Reclamation

Update to work at McLaren Tailings – Dec 2017

State to remove Soda Butte Creek from list of impaired streams

Soda Butte Creek will be delisted for metals from the 303d impaired water’s list!  This is a result of many years of hard work in mine reclamation in the watershed. Bozeman Chronicle Interview is here. Soda Butte Creek flowing into Yellowstone National Park has been contaminated with heavy metals since gold and copper mining and milling began in the New World Mining District since the 1800s. In 2010, the Department of Environmental Quality (DEQ) Abandoned Mine Lands Program began removing mine tailings from the area of the historic McLaren Mill, near Cook City, Montana. The tailings – the powdery rock that is the byproduct of the milling (metal extraction) process – were leaching heavy metals and arsenic into Soda Butte Creek into Yellowstone National Park. By the project’s completion in 2014, DEQ had removed approximately 400,000 tons of mine tailings from Soda Butte Creek and its floodplain. Following the reclamation efforts, the National Park Service Greater Yellowstone Inventory and Monitoring Network conducted water quality sampling throughout the Soda Butte Watershed. The resulting data led to a determination in November 2017 by the DEQ Water Quality Bureau which determined that metals conditions in Soda Butte Creek support all beneficial uses. The EPA has concurred with this recommendation.  For DEQ and its project partners, this marks the first time in Montana that a waterbody has been delisted from the impaired waterbody list (303d) for metals following the successful implementation of abandoned mine cleanup.  Soda Butte Creek meets water quality standards flowing into Yellowstone National Park. The project was funded through a grant to DEQ from the Office of Surface Mining Reclamation and Enforcement to address abandoned mines. A DNRC Reclamation and Development Grant provided additional financial assistance.

Pioneer was the design, engineering and oversight of the McLaren Tailings Reclamation Project. Contact:  Joe McElroy jmcelroy@pioneer-technical.com.

Project Description

 National Award Winning project.

The McLaren Tailings Abandoned Mine Site (Site) is an abandoned hardrock mine/mill site listed on the DEQ/MWRCB Priority Sites List based on site assessment conducted by Pioneer in 1993. The site is located adjacent to Cooke City, Montana at an elevation of approximately 7,500 feet and is immediately upgradient of the Lamar River located in Yellowstone National Park. Because of the site location and the potential impacts to surface waters entering Yellowstone National Park, the work required close communications and cooperation between the National Park Service, USFS, DEQ, Beartooth Coalition, and the Park County.

The DEQ retained Pioneer Technical Services, Inc. to perform site investigations and conduct a risk assessment for the Site and determined the preferred remedial alternative for the Site. Based on the risk assessment results a preferred alternative was selected for the Site and additional site investigations were completed at the Site. Based on the additional site investigation, groundwater/surface water modeling, soil stability analysis and modeling, and sediment transport modeling results, Pioneer developed a remedial design for the Site to stabilize and remove 239,000 cubic yards of mine tailings, mine wastes, and impacted soils; construct an on-site repository; reconstruct 2,000 linear feet of Soda Butte Creek and Miller Creek; construct a site wide dewatering system and water treatment system; construct 4,000 linear feet of storm water conveyance channels and infiltration systems; and revegetate 25 acres.

2014 Update: On September 8, 2014, Montana Governor. Steve Bullock, toured the nearly completed McClaren Tailings site near Cooke City, Montana. He praised the work, designed by Pioneer Technical Services and constructed by Knife River for the Montana DEQ, for helping restore Soda Butte Creek and protecting Yellowstone National Park. After 4 years, over 20 million dollars in federal reclamation money, and 256 cubic yards of waste removal, more than 100 million gallons of contaminated groundwater has been pumped and treated and the water now meets state safety standards. Pioneer provided design and construction administration on the McLaren Tailings project. The McLaren Tailings Site is located near Cooke City, MT in a valley drained by Soda Butte Creek, which runs through the site and through Yellowstone National Park, approximately five miles downstream.

2015 Update: For this project the team received a national recognition award for exemplary engineering achievement in the American Council of Engineering Companies (ACEC) 49th annual 2015 Engineering Excellence Awards competition. Previously, the team won a Montana ACEC award and the Montana Contractors Construction Excellence Award (2015). More project details here.

2016 McLaren Success Story – from the National Association of State Land Reclamationists (NASLR) – Fall 2016 issue – page 12.