Field investigations of reclaimed mine tailings at Rankin Inlet, NWT. larger image [JPEG, 87.5 kb, 434 X 325, notice]

The practice of hydrogeology in permafrost areas is in its infancy, however environmental issues related to water resources, the clean-up of industrial waste from DEW Line sites, and the disposal of mine tailings loom as important issues for the future. The implications of climate change and increased well pumping for the performance of aquifers in ice-bonded permafrost are unknown. In order to address these issues, field-oriented studies are required as well as baseline research at a fundamental level.

In 1997/98, in collaboration with Indian and Northern Affairs and the territorial government, the GSC conducted field investigations of reclaimed mine tailings at Rankin Inlet, NWT. The study is the first detailed in situ examination of the thermal, geophysical and geochemical behaviour of mine tailings during freezeback in a permafrost environment. The field work is being complemented by controlled environment laboratory testing at the GSC-Ottawa/Carleton Geocryology Research Laboratory to study the mechanics of contaminant transfer in permafrost. Field investigations of three abandoned drill sumps from hydrocarbon exploration wells in the Mackenzie Delta were also undertaken in 1997/98 to determine whether seepage of drilling brines into permafrost has occurred and to map its extent.