By 1990, the EPA had tallied up 32,645 sites of past chemical waste dumping in need of cleanup. Some of these are actual waste landfills, but many are former manufacturing sites where drums full of chemicals have been simply abandoned. The names of the most notorious appear on the EPS's National Priorities List. These are the so-called Superfund sites, names for the super fund of money put together by Congress in 1980 to clean them up. In 2009, the Superfund list contained 1,331 sites.
Sandra Steingraber (2010). “Living Downstream: An Ecologist's Personal Investigation of Cancer and the Environment”, p.69, Da Capo Press