The Mine Safety and Health Administration (MSHA) has issued an alert after an estimated 10,000 to 15,000 tons of material slid down the side of a quarry to multiple benches below, on 18 April. A front-end loader operator saw that a portion of the refuse pile (dirt dump) at the top rim of the quarry had sloughed. No workers were near the site when the material collapsed. The dirt dump was barricaded and posted against entry.
MSHA has announced a series of best practice guidelines following the incident.
- Diligent monitoring and examination of slopes for signs of instability is imperative for protecting miners.
- Maintain safe operational practices for the protection of personnel, equipment, and facilities.
- Properly grade surfaces of dump piles to permit water to drain from the area.
- Provide warning of instability so action can be taken to minimize the impact of slope displacement.
- Provide crucial geotechnical information to analyze slope stability and design slopes to prevent instability.
- Once cracks are detected, the condition should be evaluated by a qualified engineer. Equipment should not operate across cracks until they are evaluated and the stability of the ground determined.
