'Enhanced natural recovery' continues at former Steep Rock Mine near Atikokan, Ont.
Jeff Walters | CBC News | Posted: March 11, 2020 11:00 AM | Last Updated: March 11, 2020
Pits could overflow by 2070
A long-closed open pit mine near Atikokan, Ont., will continue to see some activity, as the Ministry of Natural Resources and Forestry (MNRF) looks to stabilize and remediate the former Steep Rock Mine.
The mining operations, closed in 1979 and 1980, has been monitored by the MNRF since 2003, with work taking place in the last handful of years to stabilize the massive open pit area.
Studies have looked into the impact mining has had on the soil, vegetation and water in the 5,620 hectare site, which encompasses three lakes as well as two ponds.
A consultant in 2017 recommended the MNRF proceed with what is called 'enhanced natural recovery' where water will eventually flow into Steep Rock Lake, and then throughout the watershed. But there is concern with contaminated water flowing from the former Caland pit into Steep Rock Lake.
In 2016, the MNRF estimated the Caland and Hogarth pits will overflow by 2070.
In 2018, the Ministry created a new overflow pipe through the Fairweather Dam, with work on the downstream drainage area slated for 2020. The de-commissioning and removal of an existing 1.5-kilometre pipe between Fairweather Lake and the upper discharge pond took place in 2019.
"The Ministry also plans to upgrade various dam monitoring systems, and carry out ongoing maintenance on dams for which the MNRF is responsible," said Michelle Romeo, the Regional Outreach Specialist with the MNRF.
"The Steep Rock site is large and complex and rehabilitation of the site will continue over a long period of time."
The MNRF said in 2016 the goal is to have good water quality by the time water flows to Steep Rock Lake in 2070.
Studies on the site in 2019 were conducted on the number of species on land and in the water. The MNRF said water quality is improving in the pits, with an increase in the number of invertebrate species found in the water.
The lakes themselves remain closed to the public, under the Public Lands Act due to rockfalls and hazards around the pit lakes.