Quirke Lake

Quirke Lake is located in Ontario, Canada, within the Quirke Lake basin of the Huronian Supergroup. The lake is situated near five decommissioned uranium mines and is part of the Serpent River watershed. Water flows into the lake from Dunlop Lake via the Serpent River before exiting into Whiskey Lake.

Historically, mine water was discharged into Quirke Lake, which led to environmental concerns. A 1990s study found radium-226 in trout in the lake, and summer 1993 sampling revealed a pH level of 6.3, slightly below Ontario's provincial standard of 6.5 for aquatic life and drinking water. Reintroduced trout were observed to reproduce at a slower rate compared to nearby lakes. The lake was restocked with pickerel in 2019, and in 1996, it was categorized as "fair" for trout reproduction by the Ontario Ministry of Natural Resources.

In 1996, the Canadian Nuclear Safety Commission noted controversial discussions about disposing uranium mining tailings in Quirke Lake. A 2011 Denison Mines report indicated that uranium levels at the lake's inlet still exceeded provincial standards, though radiation doses were reported as low. Environmental impacts, such as reduced benthic community richness, had diminished over time, primarily affecting areas downstream of mining sites.