Case Study 1
The Century Bulk Sample Tailings Storage Facility (BSTSF) was constructed in the late 1990s as part of the Century feasibility study.
The site was remediated in 2012 to meet current standards for decommissioning and encapsulation, and addresses acid rock drainage that was occurring. The remediation process involved:
- Defining the extent of the old tailings facility through interviews with long-term employees, reviewing historical records and surveying of the site;
- Identifying the optimal location within the operational tailings storage facility for placement of the relocated tailings and contaminated soil;
- Developing the scope of works and engaging a specialist earthmoving contractor; and
- Reclamation, relocation and encapsulation of the historic tailings and potentially contaminated cover material to the operational tailings facility.
Sampling and analysis of old tailings material were also conducted to assist in the design of a permanent encapsulation system for the operational storage facility.
Some of the challenges faced by the Century team included:
- Unknown condition of the tailings material that had been in long-term storage (e.g. saturated, self-heating or dusty);
- Operating an excavator in proximity to high-voltage transmission lines;
- Traffic management on a pre-dominantly single-lane access road;
- Unseasonal wet conditions experienced during the project;
- Material that was difficult to handle, with some very wet material requiring blending with cover material; and
- Understanding the failure of the original encapsulation system.
Once remediation has been verified, the site will be cultivated and seeded with native plant species. The project was undertaken safely, with no injuries sustained.
Project underway in 2012