The Pinchi Mine is being reclaimed, after being dormant since 1975.
Dormant Properties, which is the current version of the company which has owned the mine since its beginning, is working on an approximately $20 million reclamation of the mercury mine site.
The site is 25 km outside of Fort St. James on a limestone hill on the north shore of Pinchi Lake, and was operated as both an open pit and underground mine.
The mine operated during the Second World War from 1940 to 1944 to produce mercury for the war effort, but was closed when demand, and consequently, prices dropped.
In 1968, updated technology was used to put in a new processing plant and production resumed until 1975.
A drop in metal prices then caused the mine to be closed once again, but it was left dormant rather than closed indefinitely due to the additional untapped reserves.
However, as knowledge of mercury’s environmental impact increased and possibly due in part to less favourable metals prices, the mine was never reopened.
The company then began conducting a series of comprehensive environmental studies of the area in the 1990’s, according to Bruce Donald, manager of Dormant Properties.
These studies “ultimately led to us developing a plan of permanent closure of the site,” said Donald.
The studies helped identify the main issues the company would need to deal with on the site, namely the hazardous materials left in the processor and the tailings on site.
Donald said the company has worked closely with both the Nak’azdli and Tl’azt’en First Nations since 2005.
Members of both communities are on the technical working group for the project. Donald said Dormant Properties worked with both communities to identify their concerns and develop the closure plan.
Before even going to the Ministry of Energy and Mines, Donald said the company first got formal letters of approval for their plans from both chiefs and councils of the two First Nations.
The review process then took a year, and work was able to begin on September of last year.
The company has been working hard to utilize local resources for the project, according to Donald, and so far 40 per cent of the work force on the project has been First Nations.
“Hopefully the majority of the money that we’re spending stays in the community,” said Donald.
The reclamation of the site will involve demolition of the processor, which includes removing the hazardous materials from the buildings and shipping it to recycling or disposal facilities and nonhazardous materials then being placed in an open pit on site. The open pit will then be filled to ground level and topped with a low-permeability cap on it to shed the water off the landfill.
The large tailings impoundment area left from the mine’s operation was drained of water and will be capped with a ‘till’ cap made of clay-based soil to shed water.
The water drained from the tailings area was monitored as it was drained to ensure the water discharged was within acceptable limits.
Already, the reclamation of the site has nearly completed the demolition of the buildings and removed most of the hazardous materials, with a small amount still to be shipped off site.
The tailings impoundment area has now been capped.
During the summer, the open pit will be filled and capped, the remaining mining portals to the underground operations will be sealed, the mill area will be recontoured and the revegetation process will be started.
While most of the work will be completed by this fall, Donald said some of the final revegetation will be done next spring. Neither Nak’azdli nor Tl’azt’en First Nations were able to be reached for comment