Section 725.328  Closure and Post-Closure Care

a)         At closure, the owner or operator must do either of the following:

1)         Remove or decontaminate all waste residues, contaminated containment system components (liners, etc.), contaminated subsoils, and structures and equipment contaminated with waste or leachate and manage them as hazardous waste, unless 35 Ill. Adm. Code 721.103(d) applies; or

2)         Close the impoundment and provide post-closure care for a landfill under Subpart G and Section 725.410, including the following:

A)        Eliminate free liquids by removing liquid wastes or solidifying the remaining wastes and waste residues;

B)        Stabilize remaining wastes to a bearing capacity sufficient to support final cover; and

C)        Cover the surface impoundment with a final cover designed and constructed to do the following:

i)          Provide long-term minimization of the migration of liquids through the closed impoundment;

ii)         Function with minimum maintenance;

iii)        Promote drainage and minimize erosion or abrasion of the cover;

iv)        Accommodate settling and subsidence so that the cover's integrity is maintained; and

v)         Have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present.

b)         In addition to the requirements of Subpart G of this Part and Section 725.410, during the post-closure care period the owner or operator of a surface impoundment in which wastes, waste residues or contaminated materials remain after closure in accordance with subsection (a)(2) must:

1)         Maintain the integrity and effectiveness of the final cover, including making repairs to the cover as necessary to correct the effects of settling, subsidence, erosion, or other events;

2)         Maintain and monitor the LDS in accordance with 35 Ill. Adm. Code 724.321(c)(2)(D) and (c)(3) and 725.326(b) and comply with all other applicable LDS requirements of this Part;

3)         Maintain and monitor the groundwater monitoring system and comply with all other applicable requirements of Subpart F of this Part; and

4)         Prevent run-on and run-off from eroding or damaging the final cover.

(Source:  Amended at 42 Ill. Reg. 23725, effective November 19, 2018)