By Kelly Louiseize
It is pretty hard for government to expect mining companies to clean up after themselves when their own back yard is a little dirty.
It is the reason why the Ministry of Northern Development and Mines is putting their money where their mouth is. They have spent $47 million rehabilitating the abandoned Kam Kotia mine site located 35 kilometres northwest of Timmins and it will take another $12 million more to walk away from a job well done.
The footprint is 500 hectares. Originally, the zinc and copper mine was acquired by Wartime Metal Corp., an arm’s length government agency producing brass shell casings during the World War II in 1943-1944.
“It was rushed into production and about 10 per cent of the total mining that happened on the site occurred in that period,” says Chris Hamblin, MNDM’s mine rehabilitation project coordinator.
“The tailings were just released. They are very very high in sulphides,” he says realizing that mining houses had little knowledge of the impact this would have on the environment back in the 1940s.
Over the years, iron sulphides oxidized producing rust and sulphuric acid. That acid leaches other metals out of the tailings carrying, it into nearby water sources.
Tailings are ground up ore. The company had taken the zinc and copper from the rock, but left approximately 40 to 50 per cent pyrite, an iron sulphide.
The site closed in 1944 and was reopened in the 1960s when the bulk of the mine production occurred. In total, six million tonnes of highly sulphide rich tailings were deposited into three areas.
The south and northeast sites were unimpounded, which refers to an uncontained area, while the northwest site was impounded quite late. The dams surrounding the latter site did not stop the contaminants from leaching out. As a result mine drainage and metal leachate have severely impacted sections of two rivers and caused concern for ground water in the area.
“The tailings were saturated, but were not underwater. The further you traveled away from the mine site, the thinner (the tailings) got. Near the mine site they were multiple metres thick.”
Somewhere in between the 1960s and 1970s, a private sector company assumed ownership of the site and mine. Eventually, they went bankrupt and the land became the Crown’s responsibility.
In 2000, MNDM contracted Senes Consultants Ltd. to develop a plan for rehabilitation. They recommended a five phase approach, one year for each stage. The idea was that if there was not sufficient amount of funds to complete the job, the work undertaken so far would not have been in vain. In fact, it would have improved the site, Hamblin says.
The approach was to try to use the infrastructure on site, but reduce the footprint, basically, get the unimpounded tailings into a contained site. MNDM has successfully completed the first three phases and much of the final phase of the rehabilitation plan. However, much greater volumes of contaminated water were collected along the mine site.
Officials could not release the water into the Kamiskotia River and the Little Kamiskotia River until it met government standards. This resulted in operational challenges and causing a significant cost increase.
Phase A dealt with constructing a lime treatment plant along with an intercept ditch and other required infrastructure.
Phase B and C consisted of the excavation of the northeast and south mine tailings into a contained site on the northeast side. Phase D is a two-pronged project involving the collection of tailings from nearby creeks. It would also involves a moist cover over the newly transported tailings into the contained area. Phase E, another two project phase, involves a dry cover over the tailings as well as a clean up on all the physical hazards on site such as the open pit and recapping the main shaft.
The consulting firm predicts once all five phases have been rehabilitated the lime plant will still need to operate for at least three groundwater flushings. This is expected to take 50 years to completely remove the contaminants from the site. It also is predicted if the phases have not been fully completed, the lime plant will need to run forever. It is now expected, however, sufficient funding will be available to complete the full rehabilitation process of the site by 2009.
