In this study we investigate the spatial relationship between Superfund sites and the racial, ethnic, and economic characteristics of the areas surrounding those sites in the state of Florida. Unlike many previous environmental justice studies, we examine census tracts rather than larger aggregates such as counties or zip codes. We also look at the problem of environmental injustice longitudinally by analyzing Census data from 1970, 1980, and 1990. Such an analysis not only allows us to detect potential environmental inequality, but also to postulate on the nature and origins of this injustice. Overall, our findings indicate that Blacks and Hispanics are more likely to live near Superfund hazardous waste sites, but income and poverty indicators do not predict the location of sites. The spatial association between race, ethnicity, and Superfund sites is increasing over time, leading us to conclude that the likely cause of much of the recent environmental injustice uncovered in our results stems from indirect, rather than direct, forms of discrimination.