A confidential mining company operates and maintains a 6,000-acre tailings storage facility (TSF) with nearly 10 miles of zoned-earth perimeter dams and 8 miles of granular-earth interior dams. Portions of the existing dams exceed 100 feet in height, and are projected to eventually rise to about 150 feet. The facility has been operating continuously since the 1970s.
Barr prepared a draft closure plan for the facility that featured a comprehensive analysis of regulatory and permit requirements; concepts for reclamation and post-closure land use; and sections on deactivating, restoring, and reclaiming the TSF, including monitoring dam safety during and after the transition.
Our work on the closure plan included:
- Performing in-depth regulatory and permit assessments
- Developing two reclamation concepts
- Conducting comprehensive hydrologic and hydraulic modeling, including a facility-wide water balance, a storm event model, and a receiving-stream model
- Preparing plans for dewatering the TSF, establishing final grades, removing select structures, and modifying the existing hydraulic outlet structures for closure
- Documenting revegetation procedures and goals
- Specifying dam-safety monitoring activities for the end of operations and for the deactivation, reclamation, closure, and post-closure periods
- Developing a preliminary schedule for all five phases of closure
Barr’s background with this tailings storage facility dates to the 1960s; we helped bring it into existence. Our engineering and environmental services over the decades have encompassed:
- Hydrology, water-balance, and sedimentation studies
- Dam design and long-range planning for construction and operation
- Geotechnical studies and instrumentation
- Dam-breach analyses
- Wetland delineation and permitting