In a large class-action lawsuit, plaintiffs accused two cement manufacturers of causing, among other things, declines in home values located near the plants. The plaintiffs alleged that toxic dust, potentially containing Chromium 6, contaminated the air and soil in their neighborhoods. Using GIS tools and hedonic regression models, we analyzed the validity of alleged value diminution throughout the greater neighborhood. We also evaluated a number of other neighborhoods adjacent to sand and gravel operations to isolate potential value diminution resulting from toxic materials and emissions.