Upper Blackfoot Mining Complex
Seepage just below the tailings impoundment.
Beartrap Creek and mine waste looking north from the base of the tailings impoundment.
Please click on the tabs below for more information on the UBMC. Included are links to other agency websites that provide information related to the UBMC.
The Upper Blackfoot Mining Complex (UBMC) is a state superfund facility located about 15 miles east of Lincoln. Seeps from the tailings and waste rock dumps along with acid mine drainage from old adits have contaminated surface water, sediments, soils and groundwater. Additional contamination exists due to the 1975 dam failure that washed metals-laden tailings down the Beartrap Creek drainage and into the upper Blackfoot River.
DEQ will lead cleanup efforts in coordination with the United States Forest Service (USFS) and Montana Natural Resource Damage Program (NRDP) over the next few years. The primary goal of the cleanup is to remove approximately 1 million cubic yards of tailings and mine waste to protect human health and the environment. This protection will be accomplished by minimizing direct contact with contaminants and limiting migration and mobility of contaminants within the environment.
The UBMC, also known as the Heddleston district, is an inactive mining district which was mined intermittently from 1889 to the 1950s and explored intermittently up to the present. The UBMC is located in the headwaters of the Blackfoot River in a fairly remote location on and near national forest land, which is used by hunters and other recreationists. The town of Lincoln is about 15 miles downstream.
The main mine workings at the UBMC are the Mike Horse, Anaconda, Carbonate, Edith, Mary P and Paymaster mines and a tailings impoundment on Beartrap Creek. Tailings are the materials created during the processing of the ore rock. They are generally fine-grained and may contain elevated levels of metals. The historic mining and exploration activities in this area have resulted in numerous tailings and waste rock dumps. Erosion from the tailings and waste rock dumps along with acidic seeps and mine drainage from old adits have contaminated surface water, sediments, soils and groundwater. Additional contamination exists due to the 1975 tailings impoundment failure that washed metal-laden tailings down the Beartrap Creek drainage and into the upper Blackfoot River.
The State of Montana and the USFS successfully reached a settlement with ARCO and Asarco for environmental damages at the UBMC. Claims and interest paid amounted to approximately $39 million. More detail on the settlement can be found at the NRDP website. DEQ will lead cleanup efforts in coordination with the USFS and NRDP.
Blackfoot Valley Dispatch (Article): "Mike Horse clean-up remains a challenge, but on schedule"
Blackfoot Valley Dispatch (Article): "Clean up work resumes at UBMC"
KPAX (Article): "Work at Mike Horse Mine site resuming this week"
KPAX (Video/Article): "Agencies pleased with first year progress on Mike Horse Mine cleanup"
KPAX (Article): "Winter closes work season at Mike Horse Mine reclamation"
Blackfoot Valley Dispatch (Article): "Partial area closure remains in place for Mike horse area"
Blackfoot Valley Dispatch (Article): "Meadow Creek Road re-opened as Mike Horse cleanup ends for season"
Blackfoot Valley Dispatch (Article): "Mike Horse tour gives students, area residents chance to learn about waste removal, see progress of clean up"
Blackfoot Valley Dispatch (Article): "Cleanup of Mike Horse mine wast underway"
Helena IR (Article): "Weather, breakdowns push Mike Horse Dam behind schedule"
Great Falls Tribune (Video): "Saving the source of the Blackfoot River"
Great Falls Tribune (Article): "Waste polluting Blackfoot River hits the road"
DEQ, in coordination with the USFS and NRDP, puts out the Mike Horse Messenger, the newsletter for the Upper Blackfoot Mining Complex. It is generally published twice a year, before and after the field season, to keep interested parties informed of progress at the UBMC.
If you would like to receive the Mike Horse Messenger or any other mailings on the UBMC from DEQ, you have two choices: 1.) To receive the information electronically, please use this ListServ option to enter your email information, or 2.) use this link to enter your address information and the mailings will be put in the mail to you.
Water Treatment Plant
The water treatment plant (WTP) is now meeting final discharge limits (final limits) for all metals at UBMC. Construction modifications to meet final limits began at the WTP in the spring of 2011 so that the WTP could effectively treat the millions of gallons of metals-laden water seeping from the historic mines. Meeting final limits protects fish and aquatic life, as well as human health. The crew at the WTP has worked to modify the WTP in order to successfully meet the final limits. In addition, the WTP sludge generation process has been modified so that the material extracted from the water do not require additional treatment prior to being sent to a landfill. Even with the success of modifying the WTP to treat the mine discharges, the crew is continually working to improve plant operations, maximize effectiveness, and save money. On average, the WTP collects and processes half a million gallons of water each week. The WTP will likely operate for many decades to treat acidic mine water that will continually run from the mine adits. Acid mine drainage is an unfortunate, though fairly common remnant of mining to be addressed well into the future throughout Montana.
The UBMC cleanup will begin again on May 4, 2015. Helena Sand and Gravel will remove the remainder of the tailings impoundment and dam this year. By the end of 2015, Beartrap Creek will be in its original channel at the bottom of the valley instead of perched in a ditch on the side of the mountain, as it has been for the majority of the last 75 years.
They will continue hauling mine waste from the tailings impoundment at the headwaters of the Blackfoot River to the UBMC Repository located on Highway 279 as long as the weather permits. Trucks will be pulling onto Highway 200 from Meadow Creek Road at the bottom of Rogers Pass. The agencies remind motorists to watch for work crews and equipment as well as signs indicating reduced speed limits.
|Draft Final Feasibility Study Report||The Feasibility Study was prepared to develop, screen, and evaluate remedial action alternatives for the UBMC.||2015|
|Final Human Health Risk Assessment||Presents the findings of the baseline human health risk assessment conducted on the UBMC.||2014|
|Final Eco-Risk Assessment||Explains how the UBMC contamination in soil, stream sediment, and surface water affects the environment||2013|
|Final Remedial Investigation Report||Soil, sediment, surface water, groundwater, and biological data collected in 2007, 2008, and 2011 to determine the extent of contamination in the UBMC||2013|
|2012 Repository Decision (USFS website)||Amendment to the 2007 USFS decision changing the repository location for the Mike Horse waste||2012|
|Comparative study of locations for a repository for the Mike Horse waste||2011|
|Data collected to determine whether Section 35 held any potential as a repository for the Mike Horse wastes||2010|
|2007 Mike Horse Decision (USFS website)||USFS decision on removal in the UBMC, including the Mike Horse Dam||2007|
|2012 Mining Area Monitoring Reports||Data collected from surface water, groundwater, and stream sediments to establish existing conditions before cleanup||2013|
|2012 Section 35 Monitoring Report||Data collected from surface water, groundwater, and stream sediments to establish existing condition before the repository is built||2013|
|2011 Mining Area Monitoring Report||Data collected from surface water, groundwater, and stream sediments to establish existing condition before cleanup||2012|
|2011 Section 35 Monitoring Report||Data collected from surface and groundwater to establish existing condition before the repository is built||2012|
|2010 Mining Area Monitoring Report||Data collected from surface water, groundwater, and stream sediments to establish existing condition before cleanup||2012|
|Data collected from surface water, groundwater, and stream sediments to establish existing condition before cleanup||2010|
|Construction Investigation and Documents|
|Data collected to determine extent of removal of mine waste from the mining area and ensure proper placement in the repository||2013|
|2012 Repository Design-Level Investigation||Data collected to determine proper design of the repository||2013|
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Water Treatment Plant Coordinator
Lincoln District Ranger
Helena National Forest