I have previously noted that EPA, perhaps recognizing that an unfriendly Congress will lead to budgetary constraints on government enforcement, has been trying to facilitate citizen enforcement efforts. EPA’s latest move on this front was the recent release of “EJSCREEN: Environmental Justice Screening and Mapping Tool.” 
Putting aside the definitional concerns that many people have concerning environmental justice, there is no doubt that tools such as EJSCREEN can provide powerful assistance to groups who think that they may have suffered disparate environmental impacts. Environmental and other citizen groups are going to be using EJSCREEN and they are going to be identifying potential targets for citizen suits based on what they find.
Members of the regulated community would do well to undergo a little self-analysis and see what EJSCREEN says about the intersection of their own operations and arguably disadvantaged communities.
Forewarned is forearmed.