U.S. EPA Proposes Additional Standards of Performance for Municipal Solid Waste Landfills

On July 17, 2014, the U.S. Environmental Protection Agency (U.S. EPA) issued the results of its initial review of the existing New Source Performance Standards (NSPS) for municipal solid waste (MSW) landfills (40 CFR Part 60, Subpart WWW). The review was conducted as part of its required process to review an NSPS every eight (8) years, and to revise the standard, if necessary, to reflect improvements in methods for reducing emissions. In addition, this initial review was conducted in response to a lawsuit filed against U.S. EPA for failure to review Subpart WWW by the statutorily required deadline. Based on this review, U.S. EPA has determined that several changes to Subpart WWW were warranted, and as such, U.S. EPA has proposed a new NSPS (40 CFR Part 60, Subpart XXX) for these proposed changes. The proposed Subpart XXX will apply to MSW landfills that are constructed, reconstructed, or modified after July 17, 2014. Subpart WWW-affected landfills that do not meet these criteria will continue to comply with Subpart WWW. 

The proposed Subpart XXX includes the following provisions:

Threshold for installing controls:

Under the Subpart WWW, an MSW landfill that has a design capacity of 2.5 million megagrams (Mg) and 2.5 million cubic meters (m³) must install, operate, and maintain a landfill gas collection control system within 30 months after landfill gas emissions reach or exceed a level of 50 Mg of non-methane organic compounds (NMOC) per year. (A megagram is also known as a metric ton, which is equal to 1.1 U.S. short tons or about 2,205 pounds.) Under Subpart XXX, U.S. EPA proposes to lower the NMOC emissions threshold from 50 Mg per year to 40 Mg per year for landfills that have a design capacity of 2.5 million Mg and 2.5 million m³. Once this threshold is met, the landfill will have 30 months to install, operate, and maintain a landfill gas collection control system.

Landfill gas treatment uses:

Proposed Subpart XXX clarifies that treated landfill gas can be used for purposes other than solely as fuel for a stationary combustion device. Under Subpart XXX, landfill gas use options include vehicle fuel, production of high heating value content pipeline gas, and use as a raw material in chemical manufacturing.

Landfill gas treatment definition:

U.S. EPA proposes to clarify the criteria for filtration and dewatering as landfill gas treatment techniques. Subpart XXX will require a landfill gas water dew point of at least 45°F (rather than lowered by at least 20°F) and a temperature measurement device to be located at or immediately after the direct coalescing filter or other direct contact moisture removal device. Monitoring, recordkeeping, and reporting requirements would be updated to be consistent with the proposed definition. 

Startup, Shutdown, and Malfunction:

U.S. EPA proposes that the standards set forth in proposed Subpart XXX are applicable at all times, including periods of startup, shutdown, and malfunction. In addition, to evaluate the severity of an emissions exceedance for periods when the gas collection system or a control device is not operating, U.S. EPA is proposing to add a recordkeeping and reporting requirement to estimate emissions during such periods.

Finally, U.S. EPA has proposed other clarifications in Subpart XXX such as criteria for exempting areas from collection and control, adding criteria for when an affected source must update its design plan, and clarifying when owners or operators must submit corrective action timeline requests. 

At this time, the existing and proposed MSW Landfills NSPS do not directly regulate methane emissions. The reduction of NMOC emissions will have a co-benefit of reducing methane emissions. However, U.S. EPA is currently reviewing the MSW Landfills NSPS in light of the President’s 2013 Climate Action Plan (including its follow-up Methane Strategy document published in 2014) and is exploring opportunities to achieve additional reductions in emissions, including methane emissions.

Public comments on the proposed subpart will be accepted until September 15, 2014 and a public hearing will be held on August 12, 2014 in Washington, DC.