(a) “Disposal” means either of the following:
(1) The discharge, deposit, injection, dumping, spilling, leaking, or placing of any waste so that the waste or any constituent of the waste is or may be emitted into the air or discharged into or on any land or waters, including groundwaters, or may otherwise enter the environment.
(2) The abandonment of any waste.
(b) The amendment of the section made at the 1989–90 Regular Session of the Legislature does not constitute a change in, but is declaratory of, the existing law.