An Illinois appellate court recently ruled that the 15 year post-closure monitoring requirement for sanitary landfills under the Illinois Environmental Protection Act sets the minimum, not maximum, period, and that that the operator will be required to continue post-closure monitoring if the threat of future violations of the Act is present.

D&L Landfill, Inc., the petitioner in the case, operated a landfill in Greenville, Illinois until it ceased accepting waste in 1996.  The Illinois Environmental Protection Agency approved its final post-closure care plan the following year.  Fifteen years after the beginning of the “15 year minimum post-closure care period” identified in the plan, D&L filed an application to end all post-closure care.  The application was originally denied because affirmative remedial action was necessary at the site, including repairs to the final cover.  After that was completed, however, the Agency continued to deny post-closure certification on the grounds that groundwater contamination, although trending downward, still exceeded applicable standards.  It relied on 35 Ill. Adm. Code 807.524(c), which requires that the Agency only certify post-closure care has ended if it determines “(1) That the post-closure care plan has been completed; and, (2) That the site will not cause future violations of the Act or this Part.”  As a result, the Agency told D&L, it had to keep monitoring groundwater until the Agency was satisfied there was no longer a threat of exceedances.

D&L argued that the Agency’s position was impermissible under Section 22.17(a) of the Act, which provides that the owner or operator of a sanitary landfill must monitor gas, water and settling at a closed landfill for 15 years after the site is completed “or such longer period as may be required by Board or federal regulation.” 415 ILCS 5/22.17(a).  D&L asked the court to find that absent a regulation that explicitly extending the 15 year monitoring period, its obligations terminated as a matter of law after it completed its 15 year post-closure care plan.  The Court disagreed, finding instead that Section 22.17(a) should be construed liberally to effectuate the Act’s purposes, and the Agency’s interpretation is superior for the purpose of ensuring adequate responses to unforeseen environmental issues that arise during the post-closure period.

The decision could mean much greater uncertainty for landfill owners and operators. Compliance for 15 years with an approved post-closure care plan does not guarantee that their obligations to a site that has long since ceased generating revenue will end.  Moreover, the opinion suggests that the Agency can place the burden on the landfill to prove that no violations will occur in the future before it can obtain post-closure certification.  Accordingly, landfill owners and operators that had been counting on post-closure care costs being fixed at the cost of compliance with their approved plan might be in for an unpleasant surprise.

We will continue to monitor how this may affect landfill owners and operators – check back here for any new developments.