1. This case presents the question whether the Due Process Clause forbids the imposition of retroactive liability for conduct in violation of a statute after the administrative agency charged with administering the statute expressly declined to regulate that conduct.

Whether the Due Process Clause of the Fourteenth Amendment prohibits a state from imposing retroactive environmental liability for the discharge of a substance that was not regulated as hazardous at the time of the discharge and for which the regulated party received no fair notice of the state's regulatory position