the cases that have interpreted “disposal.” Rather, the cases fall in a continuum, with the Sixth Circuit taking an “active-only” approach in 150 Acres of Land; the Third Circuit, in CDMG Realty, and the Second Circuit, in ABB Industrial Systems, addressing only the spread of contamination (and leaving open whether migration must always be “active” to be a “disposal”); and, finally, the Fourth Circuit in Nurad, concluding that “disposal” includes passive migration, at least in the context of leaking underground storage tanks. We have not addressed whether “disposal” in § 9607(a) includes the passive movement of contamination. We have held, however, that the movement of contamination that does result from human conduct is a “disposal.” See Kaiser Aluminum & Chem. Corp., 976 F.2d at 1342 (<HOLDING>). In another context, we have held that
holding that disposal under  9607a2 includes a partys movement and spreading of contaminated soil to uncontaminated portions of property and that congress did not limit disposal to the initial introduction of hazardous material onto property holding that property of a public entity includes having exclusive control and possession of  property holding that given the breadth of the statutory definition of disposal the district court must be able to conclude that the buried drums did not leak when the defendants owned or operated the facility to make a finding that they were not liable under  9607a2 holding that the circuit courts statutory power in a divorce suit did not inherently extend to the disposal of the personal property of a party recognizing allegation that chemical contamination continued to migrate onto plaintiffs property and enter groundwater and soil