Environmental decision making is a complex process confounded by technical uncertainty, political pressure, and social interests. New calls for environmental decision-making frameworks emphasize the need for an holistic approach that incorporates technical and non-technical expertise, and participation by all affected and interested parties. In this paper, we analyze the evaluation of an environmental regulatory program to characterize the interaction of science and policy and the processing of uncertainty using concepts from science and technology studies. This demonstrates the influence of institutional goals and commitments on the uptake and use of science and the processing of uncertainty in the regulatory process. We discuss the implications of such analyses on the development of new environmental decision-making frameworks.