Excavating the regulatory process and risks posed by Alaska hardrock mine expansions

Mining can cause environmental damage if managed improperly. Environmental impact assessments are designed to evaluate the risks of mining; however, these evaluations are hindered when mines expand their operational scope beyond activities considered in the original assessment. Our study focuses on the regulatory process of mine expansion and the National Environmental Policy Act (NEPA). Our multiple case study approach analyzed expansion projects for five hardrock mines in Alaska, USA. A media review identified expansion issues for each mine that received significant public attention. For each case, we examined government documents, media, and other literature to explore research questions related to variability in the application of environmental impact assessment procedures, the breadth and depth of public process, and issues raised during public comment periods. Across case studies, we synthesized the common themes and context dependence regarding the regulatory process of mining expansion. We found wide variation in the implementation of NEPA based on different institutional and geographic contexts, which led to unique sets of public concerns. We summarized differing levels of public engagement, varying approaches to cumulative effects analyses, and difficulties accessing public documents. These results demonstrate the challenges that mine expansions pose to conducting consistent and transparent environmental impact assessments.