Lower Rainbow Valley Well Field Electrification Project in British Columbia to Reduce Annual Operating Costs by over C$1,000,000 and Reduce GHG Emissions by ∼23,000 Tonnes by 2028
Mount Milligan requires use of permitted water to maintain mill processing operations. Water is sourced from surface water withdrawals from Philip Lake and Rainbow Creek as well as withdrawals from groundwater wells. Mount Milligan operates three groundwater wells located at Lower Rainbow Valley, pumping the water to the TSF for storage and use.
Located 3.5 km away from the mine’s existing electrical distribution network, the Well Field did not have the infrastructure in place to operate by means of BC Hydro-generated electricity. As a result, the well pumps were originally powered by electricity generated from two 500 kW diesel-fired generators (one prime and one standby). The generators were costly and noisy to operate and emitted a substantial amount of GHG emissions when compared to electricity generated by BC Hydro.
Mount Milligan Mine sought to remove the diesel-fired generators located at the Lower Rainbow Valley Well Field by extending the mine's 25-kV overhead distribution network from the mine facility to the Well Field. In early 2020, with a financial commitment from BC Hydro’s Low Carbon Electrification Incentive Fund, Mount Milligan constructed the 3.5 km extension of the 25 kV electrical distribution network. With clean and reliable electricity available to operate the well pumps, Mount Milligan removed the diesel generators at Lower Rainbow Valley.
Transitioning from diesel generated electricity to BC Hydro will reduce annual operating costs by more than C$1,000,000 and avoid approximately 23,000 tonnes of carbon dioxide equivalent emissions through to 2028 – equivalent to taking more than 7,000 passenger vehicles off the road for one year.