(1) The department may designate a regulated unit (as defined in WAC 173-303-040) as a CAMU, or may incorporate a regulated unit into a CAMU, if:

(a) The regulated unit is closed or closing, meaning it has begun the closure process under WAC 173-303-610(4) or 40 C.F.R. Part 265.113, which is incorporated by reference at WAC 173-303-400 (3)(a); and

(b) Inclusion of the regulated unit will enhance implementation of effective, protective and reliable remedial actions at the facility.

(2) The requirements of WAC 173-303-610, 173-303-620, 173-303-645, and the unit specific requirements of WAC 173-303-650 through 173-303-680 that applied to the regulated unit will continue to apply to the portion of the CAMU into which the regulated unit was incorporated.