Rainy River Tailings Management Area

This project entailed the construction of clay core dams with rock shells in areas with deep saturated organic layers. At the outset, organic material was stripped to find competent ground. Once achieved, a key trench was excavated and clay core placement began. Horizontal and vertical filters and relief drains were constructed simultaneously with the core. Placement of rock for the upstream and downstream shells followed lifts of core and filter placement as required. Geotextile, geomembrane liners, and concrete cloth were also laid as part of the design. Compliance with criteria such as maximum lift elevation differentials between materials and a stringent quality control program for soils and compaction testing were critical during construction.

Overall length of the Tailings Management Dam is approximately 8,000 metres with a volume of 3.3 million cubic metres of material.

Throughout the project, seepage collection systems (including a precast concrete wet well) were developed to ensure proper drainage and protection of the natural resources. Precast concrete reclaim wells with piping and sluice gates were also installed during the construction of the dams for tailings water reuse.

Water management was a significant and ongoing concern during construction. Continuous pumping was necessary to ensure the berms were constructed under optimal conditions.

Keeping to schedule was crucial for this work. Sigfusson crews worked 24/7 to ensure milestone dates were met for the mine’s production requirements.