Despite US policy documents which recommend that in areas of environmental risk, interaction between scientific experts and the public move beyond the so-called “Decide, Announce, and Defend model,” many current public involvement policies still do not guarantee meaningful public participation. In response to this problem, various attempts have been made to define what counts as sufficient or meaningful participation and free informed consent from those affected. Though defining “meaningfulness” is a complex task, this paper explores one under-examined dimension that concerns the relationship between consent and the idea that citizens should be sufficiently informed: epistemic capacity. This paper will look at some of the work on meaningful participation and consent, give a definition of epistemic capacity, and argue that only a community with sufficient epistemic capacity can have the understanding and competence to give informed enough consent and thus participate meaningfully.