End of Post-Closure Care at Solid Waste Landfills

By: Steve Williamson, CPG

Published in the March 2020 Focus on the Environment Newsletter

For years, owners/operators of solid waste landfills in Ohio were under the false impression that after thirty years of post-closure care and maintaining financial assurance, they could just stop. Several years ago, when the 30-year periods for early landfill closures were approaching, Ohio EPA began informing the owners/operators that this was a misconception, and that they could not just stop post-closure activities; owners/operators had to demonstrate that their landfills no longer posed a threat to human health and the environment prior to ending post-closure care. Until recently, the process of doing that was not well defined. On February 28, 2020, the Ohio EPA released guidance regarding the process for ending post-closure care at solid waste landfills.

The Process

The new guidance document summarizes the Ohio EPA’s process for municipal solid waste landfill owners and operators that request to end the post-closure care period. This information also applies to industrial and residual solid waste landfills. To request an end to the post-closure care period, a sanitary, industrial, or residual waste landfill owner/operator must submit a written certification that all post-closure care activities have been completed in accordance with the appropriate rule. The certification documentation must include the following, and must be signed and sealed by a professional engineer registered in Ohio:

  • A summary of changes to leachate quality and quantity
  • The rate of leachate generation and quantity of leachate in the landfill, with an explanation of how these figures were derived
  • A summary of any on-going groundwater assessment or corrective measures
  • A summary of explosive gas migration and generation by the landfill
  • An assessment of the integrity and stability of the cap system if post-closure care activities cease

The Ohio EPA requests that the leachate, groundwater, and explosive gas summaries all include data trends for the past ten (10) years so that they can properly assess compliance with post-closure care requirements. It is evident that putting together the required demonstration, documentation, and certification will take some time, so owners/operators should not wait until the 30 post-closure care period is up prior to starting. It is suggested that owners/operators start at the 25-year mark so that there is time to go through the process. The guidance document states that the demonstration may require controlled field tests to see what happens if the leachate collection system is shut down, or if the explosive gas collection system is shut down. These tests should be accomplished by competent geologists and engineers. The guidance document suggests that owners/operators establish a close working relationship with Ohio EPA to efficiently demonstrate that their landfills no longer pose a threat to human health and the environment.

Decision of the Director

The Director of the Ohio EPA may either discontinue or extend the post-closure care period based on the data and information provided, and whether human health and safety and the environment will be protected into the future. The Director can determine that only some post-closure care activities must continue rather than all of them. If it is determined that some or all post-closure care activities can end, the landfill owner/operator will receive a letter from the Director ending those post-closure care requirements. Upon receipt of this letter, if all post-closure care is approved to end, the owner/operator can request the termination of the financial assurance instrument. If the Director determines that some post-closure care activities must continue, the financial assurance instrument should be adjusted accordingly.

Continuing Obligations

The guidance also discusses continuing obligations regardless of the post-closure status, stressing that the landowner is required to ensure that the landfill will not threaten public health, safety, or the environment in the future. These continuing obligations include:

  • Obtaining authorization in accordance with Rule 3745-513 prior to any to disturbance of the landfill cap
  • Maintaining the integrity of the landfill to ensure that it does not pollute waters of the state (under Chapter 6111 of the Ohio Revised Code)
  • Controlling explosive gas migration
  • Adhering to institutional controls

Voluntary Action Program

An interesting side note is that once a landfill is no longer subject to all of the closure requirements of Chapter 3734 of the Ohio Revised Code (i.e., the Director has determined that no further monitoring or maintenance is required, and the permit is no longer in effect), the property is eligible for the Ohio EPA’s Voluntary Action Program, and, if desired, redevelopment may occur under that program.

[1] Sanitary/municipal waste landfills – 3745-27-14; industrial waste landfills – 3745-29-14; and residual waste landfill – 3745-30-10. It should be noted that the Ohio EPA is currently in the process of consolidating the industrial and residual waste landfill rules, so the rule citation for industrial waste landfills will likely change in the next year or so.

Steve Williamson is a Senior Scientist with Cox-Colvin & Associates, Inc. He holds a BS degree in Environmental Health and an MS degree in Hydrogeology from Wright State University. Mr. Williamson has over 30 years’ experience working on brownfields, solid and hazardous waste, and groundwater contamination projects in Ohio and the Midwest.