Section 725.410  Closure and Post-Closure Care

a)         At final closure of the landfill or upon closure of any cell, the owner or operator must cover the landfill or cell with a final cover designed and constructed to accomplish the following:

1)         It must provide long-term minimization of migration of liquids through the closed landfill;

2)         It must function with minimum maintenance;

3)         It must promote drainage and minimize erosion or abrasion of the cover;

4)         It must accommodate settling and subsidence so that the cover's integrity is maintained; and

5)         It must have a permeability less than or equal to the permeability of any bottom liner system or natural subsoils present.

b)         After final closure, the owner or operator must comply with all post-closure requirements contained in Section 725.217 through 725.220 including maintenance and monitoring throughout the post-closure care period.  The owner or operator must do the following:

1)         It must 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)         It must maintain and monitor the LDS in accordance with 35 Ill. Adm. Code 724.401(c)(3)(D) and (c)(4) and Section 725.404(b), and comply with all other applicable LDS requirements of this Part;

3)         It must maintain and monitor the groundwater monitoring system and comply with all other applicable requirements of Subpart F;

4)         It must prevent run-on and run-off from eroding or otherwise damaging the final cover; and

5)         It must protect and maintain surveyed benchmarks used in complying with Section 725.409.

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