Faro Mine, one of the largest contaminated sites in Canada is moving ahead with the next phase in its remediation.
On May 31, 2019, the Government of Canada announced that Pelly Construction Ltd. was awarded a major contract for the second phase of the North Fork Rose Creek realignment project that will prevent the creek from coming into contact with contaminated water on the Faro Mine site.
The Faro Mine site is located in the Yukon and was once the largest open pit lead-zinc mine in the world. It was abandoned in 1998 and encompasses 25 km2 and contains 70 millions tonnes of tailings and 320 million tonnes of waste rock, according to the Government of Canada. Waste rock and tailings must be treated as they can leach heavy metals and acid into the ground and water.
According to Crown-Indigenous Relations and Northern Affairs Canada (CIRNAC), the $44.4 million dollar realignment project is part of the Faro Mine remediation plan. It includes the construction of a new 1.9 km water channel, road construction, water management and other related works. A 11.5 km diversion channel that was built earlier in 2019 will be used to divert the creek while construction is being done.
The Faro Mine remediation plan is expected to take 15 years to complete and will be followed by 20-25 years of testing and monitoring.
According to CIRNAC the plan includes:
Collect and treat contaminated water: The contaminated water management system will collect, store, transport and treat contaminated water. This system will help protect the downstream environment from contaminants found in seepage and groundwater.
Divert clean water: The clean water system will ensure that clean water is kept away from contaminated water. This will involve diversions and ditches, and may also include some settling or polishing ponds. Reducing the amount of clean water that becomes contaminated will be critical to reducing the volume of water and contaminants that need to be treated by the contaminated water management system.
Covers: Earth and rock covers will be placed across the site to keep ore, waste rock and tailings waste away from humans and wildlife. The covers will also reduce the infiltration of water into the affected areas and provide an area to support new vegetation growth. As with the diversion of clean water, reducing the volume of water and contaminants that are draining from the waste rock dumps and tailings areas will be important to decrease the amount of water needing to be treated.
Adaptive management: Adaptive management means being flexible. The Faro Mine site is complex and experience shows that it is impossible to foresee all problems that can arise. By monitoring the site, we can watch contaminant levels and take action if unacceptable levels of contaminants enter the downstream environment.