PHOTO: Historic photo of the Caland Ore operation on Steep Rock Lake. For more, visit Atikokan Centennial Museum on FaceBook
Consultants studying the Steep Rock mine site suggest allowing the abandoned mine pits to refill, and then allowing the overflow to follow its natural course back into the Seine River system via the West Arm of the Steep Rock Lake.
The overflow would cross into the West Arm in the area of the Narrows Dam – the same route it took until the mine was developed in the late 1940s – early 1950s.
The consultants, AMEC Foster Wheeler, chose this option from among six laid out early last year. Generally speaking, each of the others involved a more dramatic intervention at the site. Most (like the one chosen) saw the overflow from pit lakes rejoining the Seine River system west of Atikokan; one would have redirected the flow through Atikokan (east to west) via Strawhat Creek and the Atikokan River.
At this point, the option chosen is a long-range concept designed to guide how the site will be managed.
“Rehabilitation of the site will unfold over a long period of time,” wrote MNRF regional director Amanda Holmes in a March 6 letter to the Town. “Rehabilitation planning and implementation will require a flexible approach to be responsive to the complexity of the site and evolving conditions (e.g., advances in technology, changing climate, response of the environment to clean-up actions).”
There is one especially significant unknown with allowing the overflow to run through the West Arm. When the Hogarth and Roberts pits where developed in 1951-52, the silt removed from them was dumped on the ice covering the West Arm. When that silt washed down the Seine River system, it caused major fish habitat and water supply problems downstream, all the way to Rainy Lake.
The problem was so acute Steep Rock Iron Mines decided to isolate the West Arm, and divert the Seine River system around it.
So, the question is: How will those sediments react nearly 120 years later when the West Arm rejoins the Seine River system? (The pit lakes are expected to overflow around 2070.)
That issue is among many the MNRF will study in coming years.
So far, study of the site suggests the pit waters are of fairly good, and improving, quality. This, combined with stratification effects (the best quality water tends to be at the top levels on the pit lakes, the levels from which water will spill out into the broader environment), suggests the overflow that reaches the West Arm will be of good quality.
The MNRF will study an idea to add water to the pits at some point to help ensure good water quality.
Holmes said study of the site and rehab plan development will continue, and that as specific actions are planned, there would be additional consultation with the Town and residents.
Not yet on the radar are the Town’s two main concerns around the rehab effort: the fate of Highway 622 and of the Mount Fairweather downhill ski centre.
In about 30 years – unless there is some sort of intervention – water accumulating now in the old pits will naturally flow back into the East Arm of Steep Rock Lake, between the Fairweather and Hardy dams, and flood the ski hill and about a kilometre of Highway 622.