2016 Update: The Montana Contractors’ Association presented an Environmental Excellence awards to this project. The UBMC Phase 2 project won the Special Recognition – Water Quality award. Details on the project.
The Upper Blackfoot Mining Complex (UBMC) encompasses 6 square miles of historic mining areas at the headwaters of the Blackfoot River. Pioneer developed a feasibility study of the mining complex. For the 2013-2015 study, we combined 13 separate exposure units from the remedial investigation into 5 evaluation areas for efficiency. Pioneer’s efforts revealed the following information about the area:
- Elevated levels of metals in soil, sediment, groundwater, and surface water.
- 10 tributary streams to the Blackfoot River.
- More than 250 mining related features throughout the site, including waste rock dumps, collapsed adits, subsidences, exploration pits, and discharging adits.
- Steep, rugged, and forested terrain with difficult access and at an elevations between 5,200 and 7,200 feet.
- Highly mineralized area with ore-body at or near the surface at multiple locations.
- Total estimated volume of mining-related waste (tailings, waste rock, and impacted soils) of 800,000 cubic yards.
- Multiple landowners: U.S. Forest Service, Montana Department of Environmental Quality, and private owners.
- Previous reclamation/remedial actions at the site included removals, construction of 3 repositories and an active water treatment plant to treat contaminated groundwater from the Anaconda and Mike Horse mine sites.
- Groundwater contamination at the Carbonate mine site required evaluation of innovative treatment and source separation methods.
- 136-acres of impacted wetlands (marsh) areas within the Blackfoot River floodplain. Marsh areas contained several thousand cubic yards of tailings and impacted sediments from upstream tailings impoundment failure.
Additional information on the UBMC is below: