Despite more than 40 years of experience with Environmental Impact Assessment (EIA) in the United States, little is known about who participates, how they participate, and whether agencies are responsive. This study explores the role of public participation in the American federal government EIA context, focusing on the different languages used by residents and administrators. Residents of affected geographic areas use nontechnical language to address concern over individual impacts, whereas administrators use technical language about aggregate impacts and focus on justification of decisions, rather than altering decisions based on public feedback.