Environmental surveillance data-in particular, data from air monitoring conducted by grassroots community groups-is presumed to empower community members with respect to neighboring industrial facilities; furthermore, extensions of datacollecting ability are assumed to represent expansions of empowerment. This paper challenges the idea that empowerment follows from the collection of copious surveillance data, arguing instead that the degree and kind of empowerment environmental surveillance supports is determined by the manner in which surveillance data is made meaningful. Examining contrasting interpretations of environmental surveillance data, the paper shows how they variously construct empowerment in terms of the power to define issues, the power to enforce laws, and the power to choose. The three forms of empowerment vary in the level at which they enable community groups to act-suggesting that the empowering potential of surveillance rests in large part on strategic interpretive choices.