During the process of exploring for hydrocarbons, drilling sump are used to permanently store the waste associated with drilling. In the Mackenzie Delta region of Canada's western Arctic, more than 150 drilling sump were constructed for this purpose. Although the areas surrounding the sumps were believed to be frozen by the surrounding permafrost, recent findings suggest that these areas may actually be thawing. In this study, the authors examine the environmental effects of this type of drilling sump containment loss in the Mackenzie Delta.