Approximately one quarter of the northern hemisphere landmass contains permafrost, which is thawing due to climate change. Thawing permafrost is expected to drive major shifts in groundwater availability and quality in northern and mountainous regions. In Canada’s Yukon Territory, over 90 % of the population relies on groundwater resources as the principal drinking water supply. However, groundwater in several areas of the Yukon can contain naturally elevated concentrations of uranium and arsenic that threaten community drinking water supplies and also pose a risk in prospective mining. Recent research has shown that permafrost thaw leads to more active groundwater circulation and changes in the chemical composition of groundwater, including release of previously stored organic carbon and increasing biogeochemical fluxes of various solutes.

This proposed research will explore relationships between permafrost thaw and groundwater chemistry in northern regions, with a specific focus on groundwater vulnerability to hazardous metals that pose current and future risks to water security in the Yukon and other northern regions. This research will integrate groundwater vulnerability mapping, targeted field sampling, and controlled laboratory studies to improve understanding of the underlying drivers of metal release to groundwater in permafrost environments. This research has important implications for subarctic and arctic regions experiencing climate change induced permafrost thaw and will help governments and communities understand and manage this growing water security risk.