The goal of this study is to demonstrate how rhetorical analyses of public discourse artifacts and practices reveal science as a civic discourse---with highly epideictic and deliberative purposes---that guides public policy decisions made by non-expert, civic leaders. Though typically recognized for its forensic function, little is written about how the epideictic function of scientific discourse politically performs in public policy debates about the environment. Nor is much written about the connection between the epideictic and deliberative functions of scientific discourse and the resolution of public controversies. To demonstrate the intersection of the political and scientific, I present a case study in which two opposing scientists attempted to shape public policy using scientific reports. These reports contained conflicting evidence and claims concerning the suspected emission and deposition of dioxin from a Midwestern power plant to the food sources of the Inuit who reside in the Arctic Circle. Specifically, I analyze what rhetorical moves these scientists used to construct scientifically based arguments in both the initiation and resolution of the environmental conflict, and I speculate how expectations appropriate for scientific discourse complicated (and possibly conflicted with) understanding about what was suitable for discourse surrounding the controversy. Using the analytic categories of genre and delivery, frames and values, ethos and identity/image, I locate three rhetorical actions that may be helpful to professional communicators, civic scientists, environmental advocates, public officials, and general citizens when reading and responding to the discourse that is created to initiate and resolve an environmental controversy: (1) the use of warrants to express non-scientific values, (2) the difference in rhetorical situations and generic conventions that surround scientific and environmental discourses, and (3) the creation of a "web of discourse and activity" by scientists seeking change in public policy.