Water and Natural Resources
Project Name: Abandoned Underground Coal Mines Mitigation and Reclamation
Project Location: Southwest Montana
Services Provided:
- Construction management and administration
- Engineering and design
- Erosion control and stream channel restoration
- Mine permitting, reclamation, and compliance
Trihydro was contracted by the Montana Department of Environmental Quality (MDEQ) Abandoned Mines Section to complete the reclamation of two abandoned underground coal mines in Gallatin and Park Counties, Montana. The purpose of the reclamation project was to limit human and environmental exposure to contaminants of concern (primarily coal slack) and to reduce the mobility of contaminants.
The reclamation plan involved removing approximately 42,000 cubic yards of coal slack and waste rock at the Meadow Creek and Mountain House complexes and disposing of these wastes in on-site repositories. The reclamation also included closing a mine adit while protecting historical structures. Waste repositories were designed to completely contain the coal waste, blend in with existing topography, and provide a minimum of 4 feet of cover material to reduce environmental impacts and allow vegetation to reestablish.
Trihydro provided design and bid document preparation on a tight schedule that addressed:
- Improvement of existing roads
- Closure of a mine opening (adit)
- Removal and disposal of debris while protecting historical structures
- Construction of on-site disposal repositories in mountainous terrain with attention to landowner concerns
- Excavation, hauling, and placement of coal waste
- Field design of subsurface rock drains
- Field design of runoff channels
- County approach and encroachment permitting
- County road culvert replacement