35 Ill. Adm. Code 807.507
Partial Closure
Section 807
Section 807.507 Partial
Closure
a) The requirements of Subparts E and F apply to the entire site
unless the permit divides the site into definite areas which include one or
more units, in which case the operator may provide separate closure and
post-closure care plans and cost estimates for each area. In such a case the
Agency shall treat each area as a separate site for purposes of financial
assurance.
b) If a site includes a disposal unit, then the operator must
provide financial assurance for closure of associated treatment and storage
units, even if the site is divided into areas as provided in paragraph (a).
c) Post-closure care of areas formed by dividing a site shall
continue until post-closure care of the entire site is completed.