Water quality and associated microbial ecology in selected Alaska Native communities: Challenges in off-the-grid water supplies

The availability of safe water for potable purposes in Alaska Native communities is limited due to naturally occurring metals and contaminants released from anthropogenic activities, such as drilling and mining. The impacts of climate change are magnified in the arctic and sub-arctic regions and thus have the potential to mobilize contaminants and exacerbate the water contamination problem. Alaska Native communities are vulnerable to such changes in their water quality because of their remote location and limited access to resources. This study initiates an assessment of water quality, including its microbial ecology, in off-the-grid Alaskan water supplies (i.e., primarily groundwater wells). In particular, water quality data were collected from nine communities (22 ground water wells). Water quality analyses included basic water quality parameters, a suite of metals relevant to human health, and microbial community composition. Results revealed location-specific elevated arsenic concentrations based on the underlying geological formation, particularly in the areas located in the geological formation of the McHugh Complex. Diverse microbial communities were observed, and the grouping appeared to be based on elevation. These findings present evidence of compromised water quality in an understudied area in the United States. The results from this study should be considered as a snapshot in time, which highlight the importance for further systematic studies in similar off-the-grid communities.