Subject to Section 19-8-106, any site is eligible for participation in the voluntary cleanup program created under this chapter except:
(1) a treatment, storage, or disposal facility regulated under 42 U.S.C. 6901 et seq.;
(2) that portion of a site that is on the national priorities list; or
(3) that portion of a site for which a state or federal enforcement action is existing or pending against the applicant for remediation of the contaminants described in the application.