(1) the owner and operator of a vessel or a facility, (2) any person who at the time of disposal of any hazardous substance owned or operated any facility at which such hazardous substances were disposed of, (3) any person who by contract, agreement, or otherwise arranged for disposal or treatment, or arranged with a transporter for transport for disposal or treatment, of hazardous substances owned or possessed by such person, by any other party or entity, at any facility or incineration vessel owned or operated by another party or entity and containing such hazardous substances, and (4) any person who accepts or accepted any hazardous substances for transport to disposal or treatment facilities, incineration vessels or sites selected by such person, from which there is a release, or a threatened release which causes the incurrence of response costs, of a hazardous substance . . . .
First because, disposal is defined primarily in terms of active words such as injection, deposit, and placing, the potentially passive words spilling and leaking should be interpreted actively; second release must be broader than disposal, because disposal is included within release . . .; and third, it makes sense of the statutory scheme as well as the words themselves to have disposal stand for activity that precedes the entry of a substance into the environment and release stand for the actual entry of substances into the environment.