Nonknowledge and knowledge are concomitant produced (Böschen & Wehling, 2010), creating a dynamic of knowledge-nonknowledge production. I argue that this dynamic can be used as an original framework to analyze formal and informal power (Frickel et Moore 2006). This paper is based on a study case of an exploitation project called Crétacé 4000, an underground disposal of chemical waste in southwestern French, Lacq. The analysis is based on the identification of the responsible actors for knowledge production – and hence also nonknowledge. I examined legal documents, and minutes of meetings held by the Local Monitoring Committee (LMC), and analyzed the French press and scientific articles about the case. The reasoning of this paper is constructed to show that i) the State does not specify who is responsible for knowledge-nonknowledge production, reinforcing unequal distribution of power; ii) LMC has favored the knowledge-nonknowledge dynamics produced by industry; iii) there are knowledges-nonknowledges being produced other actors, such as scientists, that are, until now, marginalized in the process. My results confirm that the privileged dynamics of knowledge-nonknowledge production are centered on industrial actors. The main contribution of this article to the STS discussion on resides in the opportunity to go further, showing that this kind of ‘monopoly’ reduces the options society has to handle uncertainties and the unknown, leading society to look differently at who is producing knowledge. In this way, the proposed framework provides an innovative and dynamic approach to studying power from a knowledge-nonknowledge perspective, which is likely to be developed within other STS study cases.