WHILE SOME GROUPS, such as the Grassroots Recycling Network, are protesting the U.S. Environmental Protection Agency's (EPA) rule allowing states to issue Research, Development and Demonstration (RD&D) permits to landfills that want to deviate from traditional landfill operating rules for research [See “Group Challenges Landfill RD&D Rule” on page 6], the waste industry plans to proceed as though the rules will be upheld by the Washington D.C. Circuit Court of Appeals. Early indications are that states are responding in the same way.

Why the continued interest despite the opposition?

The new RD&D rules allow waste companies to have more flexibility with traditional Municipal Landfill Criteria regarding run-on control systems, liquid restrictions and final cover requirements so that they can develop bioreactors, the EPA's Paul Cassidy says.

Cassidy was part of the 2004 Waste Tech Landfill Technology Conference panel discussion on bioreactors that included Greg Cekander, vice president of Environmental Management for Waste Management, Inc. (WM), Houston; Richard Carmichael, Texas Commission on Environmental Quality; Richard Watson, Delaware Solid Waste Authority; Matt Davies, Republic Services Inc.; and Ed Skernolis of WM.

The first step in beginning bioreactor processes requires getting state DEP landfill RD&D rule permits approved. To increase the likelihood that the state approves a permit, Watson recommended landfills:

  • address the cover and the need for little or no soil;

  • address the surface addition of the liquid;

  • write the leachate breakout corrective action into the permit; and

  • create an atmosphere to avoid notice of violations (NOVs).

Once the permit is approved, landfill operators then must tackle geotechnical stability, head on liners, meeting groundwater protection standards, potential gas increases, odor control, infiltration and permeability during the final cover stage, and financial assurance.

The panel stressed that addressing these issues will require nontraditional landfill management methods with new landfill gas (LFG) estimating models and corrective action plans. For example, leachate breakouts often are a concern with bioreactors, but the panel said breakouts can be managed by letting cells rest, as well as by working with regulators to address leachate breakouts as a potential concern and identify leachate management techniques and engineering approaches that can be used to mitigate any potential issues. Skernolis noted that it is important for the waste industry to work with state regulators to ensure both parties have a clear understanding of the processes in place to address leachate breakouts or any other issues that may occur. He added that both parties should work together to create a “blueprint” in the permit that would outline appropriate responses and a course of action.

In terms of daily cover, operators also should look for watered-out LFG collection systems and the misperception of leachate head on the liner. Operators should use high-permeability alternative covers and acknowledge that bioreactor operations near slopes will require modification, Davies said. Tracking daily cover use is key to managing a bioreactor effectively, as well as to providing state regulators with thorough documentation about the landfill.

Aesthetics of a bioreactor landfill is important; perception is reality, Davies said. The same sentiment applies to odors, which can be the single biggest risk to bioreactors and limit potential sites. So to mitigate problems, Davies recommended landfill managers handle LFG proactively by controlling gas collection systems and responding to complaints early in the process to maintain community support. Odor control systems can be pulled behind a tractor or applied with a high-pressure hose system. Another option is to pretreat liquids in tankers prior to adding them to the waste.

Finally, educating regulators, operators and the community is essential to maintaining successful and profitable bioreactor landfills, the panel agreed. “Bioreactor landfills require a substantial amount of commitment from the operator because it is a change in the way we are managing the waste,” Cekander said. “It is important that we monitor bioreactor projects closely and that we collect sound data that the federal and state agencies can use to effectively judge the technology.”

Keep in mind that a bioreactor's operator will be required to submit an annual report documenting the project's performance. Data on airspace gain, leachate disposal cost avoidance, liquid waste treatment, beneficial LFG projects for early gas recovery, greenhouse gas credits, good operations recordkeeping, and faster landfill stability and future post closure can help to measure a project's success, Watson said. The information gathered will be used by the EPA to decide on the type of federal action needed to make bioreactors a common waste management system over the next few years.

Bioreactors are promising because they potentially create landfill airspace savings and reduce leachate treatment and post-closure costs, the panel said. The EPA is hoping the RD&D permit rule will prove that the promise rings true.

CHALLENGES TO LANDFILL BIOREACTOR PROJECTS:

  • geotechnical stability;
  • head on liners;
  • meeting groundwater protection standards;
  • potential gas increases;
  • odor control;
  • infiltration and permeability during the final cover stage;
  • financial assurance;
  • and educating regulators and the community about the processes, difficulties and benefits of bioreactors.