A brownfield is a potentially contaminated piece of property that has been abandoned or is just lying vacant. A brownfield can be a former industrial property or a former residential property that has contamination problems from asbestos or illegal waste dumping. Most brownfields are located in or near inner metropolitan areas, but they can also be located in rural areas with mines and other industries. The exact number is difficult to determine, since owners may be reluctant to report contaminated properties because of the potential negative effect on property values. Superfund set up a framework of strict liability for contaminated properties and also created a large federal fund, financed by taxes on petroleum and other chemical industries, to finance litigation and cleanup of severely contaminated sites.
Liability is strict, joint and several, and retroactive.
That means that the EPA can sue one of several contributors to pollution, can sue for pollution that occurred before environmental regulations were in place, and does not need to prove negligence in order to hold a party responsible.