Science Inventory

Permitting of Landfill Bioreactor Operations: Ten Years after the RD&D Rule


Tolaymat, T. AND J. Morris. Permitting of Landfill Bioreactor Operations: Ten Years after the RD&D Rule. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-14/335, 2014.


Municipal solid waste (MSW) landfills in the United States have conventionally been operated with the objective of minimizing the amount of moisture entering and retained in the waste. This landfill management approach hinders biological activity and leachate and landfill gas (LFG) production, which reduces the risk of groundwater and atmospheric pollution following the containment principles described in Subtitle D of the Resource Conservation and Recovery Act (RCRA) (Federal Register, 1991). The Subtitle D regulations codified under 40CFR Part 258 thus restrict disposal of bulk free liquids in MSW landfills and require low permeability final cover systems. To promote innovative landfill technologies in the U.S., including adoption of alternative cover systems and bioreactor technology, on 22 March 2004 the EPA published the Research, Development, and Demonstration (RD&D) Permit Rule (the Rule) (Federal Register, 2004). The intent of the Rule is to further encourage innovative approaches within RCRA. Of interest to this report, the Rule allows Subtitle D landfills a variance option for adding bulk free liquids at a MSW landfill if a demonstration can be made that such a variance will not increase risk to human health and the environment relative to standard permit conditions for the landfill. Consistent with the Subtitle D regulations, the Rule is intended to be self-implementing, giving each state or tribal community the authority to permit landfill bioreactors that may otherwise not have been allowed previously under Subtitle D regulations.


Prior to promulgation of the Rule, there were approximately 20 full-scale bioreactor projects in North America, including one in Canada. Of these, six were permitted by EPA (four Project XL sites and two projects listed separately under a cooperative research agreement at the Outer Loop Landfill in Kentucky). In March 2014, there were about 40 bioreactor projects reported, including 30 active RD&D projects in 11 approved states and one project on tribal lands. Wisconsin features the largest number of projects at 13, due primarily to the fact that landfill owners in the state must either eliminate landfill disposal of biodegradable materials or to achieve the complete stabilization of deposited organic waste at MSW landfills within 40 years after closure. Most landfill operators have selected a bioreactor approach to attempt to achieve the latter goal. In summary, only 16 of 50 (32%) states have currently adopted the Rule, meaning that development of RD&D permitting procedures that are consistent with EPA’s requirements has generally not occurred. The predominant single reason cited for not adopting the Rule was lack of interest amongst landfill facilities in the state. Subtitle D and its state derivatives already allow leachate recirculation over prescriptive (i.e., minimum technology) liner systems, which is often the primary goal of site operators seeking to control leachate treatment costs. Other reasons related to concerns over increased time, cost, and complexity of the permitting procedure for both state personnel and individual applicant sites. From a site’s perspective, therefore, the extra RD&D permitting needs and costs for operation and data collection are a significant deterrent given insignificant market pressure or other economic incentives for accepting bulk commercial liquids. Restricting wet landfill operation to leachate recirculation is thus a more attractive and simpler alternative. Few technical concerns over site stability, environmental protection, or public safety were raised as issues against Rule adoption. This is a positive finding in that it means that the EPA could potentially increase the level and rate of Rule adoption by streamlining the administrative process rather than performing a time-consuming technical review procedure. Some frustration was expressed over the long lag time in the approval process following Rule adoption by states, but this generally appears misplaced. Although three states did wait over a year for approval, the average waiting time was only seven months, with four states waiting three months or less. In this regard, it is also noted that delays are common in almost all new permitting processes: applications based on familiar designs are easily approved while those based on innovative, complex designs are slowed by the unfamiliarity of permit reviewers. This works against innovation, as recognized by the Interstate Technology and Regulatory Council (ITRC), which is why that organization, with the support of EPA, prepares guidance documents to assist permit reviewers deal with new technologies.

Record Details:

Product Published Date: 12/22/2015
Record Last Revised: 01/29/2016
OMB Category: Other
Record ID: 310902