Red Chris Mine

CLIENT: Newcrest Red Chris Mining Limited

LOCATION: Red Chris Mine, Iskut, British Columbia, Canada

The Red Chris project is an open pit mining operation with nameplate capacity of 30,000 tonnes per day that produces copper and gold concentrate. BGC is the Engineer of Record for the tailings impoundment.

On an annual basis, BGC’s design work includes tasks required to raise the dams: conducting annual dam safety inspections, preparation of issued for construction drawings, instrumentation design and installation, dam sizing and deposition planning, construction monitoring and quality assurance of the annual raises, preparation of construction records reports; water balance support, design of spillways, diversion ditches, dam breach assessments for the facility; review of groundwater monitoring data, design of a seepage interception pump back system seepage modelling, terrain mapping and groundwater modelling.

The Red Chris project site has been subject to several glaciations resulting in complex foundation conditions for the tailings facility. BGC compiled the results of historical data and site investigation and laboratory testing programs to develop an engineering geology model that is the basis for stability modelling and dam design and supports the conceptual hydrogeologic model for the project.

The tailing impoundment overlies thick overburden materials including glacial sediments, colluvium, alluvium, and bedrock. The North Dam will be constructed to a height of 115 metres using cyclone sand and a compacted till core, while the South Dam will be constructed to a height of 85 metres using sand and gravel and is partially lined. Tailings are deposited conventionally into the 500 hectare impoundment.

BGC is providing ongoing hydrogeological services to the Red Chris Mine to support current open pit operations, regulatory compliance and feasibility studies for a proposed block cave expansion. Work has included hydrogeologic field investigations and 2D seepage modelling to support construction and operation of tailings dams and designs for monitoring and interception of seepage from the tailing’s impoundment. BGC has also developed the site-wide 3D numerical groundwater flow model to support the project through operations as well as pre-feasibility studies for a proposed block cave and tailings impoundment area expansion. BGC continues to support the evolution of the conceptual hydrogeologic model, preparation of annual compliance groundwater monitoring reports and growth of the mine’s groundwater monitoring network around the open pit, in the tailings impoundment and waste rock storage areas.