Work to assess groundwater contamination from Cameco’s northern Key Lake Mill will start later this month. Spokesperson Carey Hyndman says the most likely source of the increased uranium levels in one of their monitoring wells has been removed and it’s being monitored often. Cameco reported the increase to provincial and federal regulators last December. Cameco closed down Key Lake and the nearby McArthur River mine in 2018 because of weak uranium prices.