Key Findings:

• Toxic waste dumps — known as Superfund sites — still plague American communities 27 years after the U.S. government set up a program to identify and clean up the country’s worst sites. A one-year investigation by the Center for Public Integrity revealed the beleaguered state of the Environmental Protection Agency’s Superfund effort. The project examined all 1,624 such sites and named each of the companies and government agencies linked to the most sites, as well as the cleanup status and contaminants at each site.