Halet Lake is the common name for a small lake in Northern Ontario used by the operators of Coldstream copper mine to dump half a million tons of sulphide tailings in the mid 1960s.

Halet Lake
Halet Lake is located in Ontario
Halet Lake
Halet Lake
LocationThunder Bay District
Coordinates48°36′24″N 90°33′55″W / 48.606764°N 90.565390°W / 48.606764; -90.565390
Primary outflowsWawiag River
Basin countriesCanada
Max. length0.4 km (0.25 mi)
Max. width0.4 km (0.25 mi)

Description

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Halet Lake is located east of Grassy Lake and northeast of Burchell Lake.[1]

History

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Halet Lake became known as "Tailings Management Area 2" of the mine after the Department of Lands and Forest provided permission for the dumping.[1] The dumping occurred on the south west shore of the waterbody[2] between 1962 and 1967, forming a 3-hectare beach of tailings.[3]: 146  The tailings produced acid and contaminated downstream bodies of water, including Wawiag River and Burchell Lake.[3]: 146 

In 1998, the majority of the tailings were moved to below Halet Lake's water line, and 4,000 tons moved to the other tailings dump area of the Coldsteam copper mine site (Tailings Management Area 1). The move was undertaken to inhibit oxidisation and acid creation.[3]: 146 

The water level dropped prior to 2008 exposing the tailings, but covered them after 2008 after a beaver dam raised the water level above the tailings. In 2012, EWL Management Limited built a structure to permanently raise the water levels above the tailings dump.[3]: 146 

See also

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References

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  1. ^ a b Burns, R. Cecil; Orava, David A.; Zurowski, Michael; Mellow, Robert J. "A Case Study of the Rehabilitation of Sulphide Tailings at the Coldstream Mine Tailings Management Area No. 2" (PDF). Laurentian University. Archived (PDF) from the original on 2022-01-22.
  2. ^ "Abandoned Mine Inventory Record 08489". www.geologyontario.mndm.gov.on.ca. Retrieved 2023-07-02.
  3. ^ a b c d 58th Annual Meeting, Institute of Lake Superior Geology, Thunder Bay, Ontario, May16-20 2021, Part 2 - Field Trip Guidebook Archived 2022-01-22 at the Wayback Machine, Institute of Lake Superior Geology