EPA鈥檚 new rules update the Clean Air Act regulations applicable to new and existing landfills that were promulgated in 1996. The rule for existing landfills updates Emission Guidelines that generally become applicable through state implementation plans under section 111(d) of the Clean Air Act. 聽The other rule regulates 鈥渘ew鈥� landfills under the New Source Performance Standards (鈥淣SPS鈥�) program, specifically those landfills that commenced construction, reconstruction, or modification after July 17, 2014, under Clean Air Act section 111(b). 聽The rules themselves are nearly identical in substance, but may be implemented in a different manner depending on the state. 聽As of August 1, the rules have not yet been published in the Federal Register, so the 60-day time period to challenge them in the D.C. Circuit has not begun to run.
Regulatory Changes
- EPA Lowers the Emissions Threshold for When Landfills Must Install Controls
- Under the old NSPS and Emission Guidelines, EPA required the installation of controls in the form of a gas collection and control system (鈥淕CCS鈥�) at any landfill that met both a design capacity threshold and an emissions threshold. 聽The design capacity threshold has not changed with these new rules 鈥� it is 聽2.5 million megagrams by mass and 2.5 million cubic meters by volume.
- The emission threshold has, however, been lowered. 聽The previous threshold was set at 50 Mg/yr of non-methane organic compounds (鈥淣MOCs鈥�), a surrogate representing overall emissions of landfill gas. 聽The new threshold is set at 34 Mg/yr of NMOCs under both the Emission Guidelines and the NSPS.
- EPA Adopts a New 鈥淭ier 4鈥� Surface Emissions Testing Methodology
- EPA is also finalizing a new emissions calculation methodology called 鈥淭ier 4鈥� for determining when a GCCS needs to be installed at a landfill. 聽Landfills that meet the design capacity threshold are required to calculate their projected NMOC emissions according to methods known as 鈥渢iers鈥� within the regulations. 聽Generally, a landfill owner starts at Tier 1, and if emissions are not projected above the emissions threshold under that method, GCCS need not be installed. 聽If the emissions threshold is met or exceeded at Tier 1, the landfill owner may move on to the next tier or elect to install controls. 聽If, at the next tier, the emissions threshold is not met or exceeded, the landfill owner is not required to install controls. 聽The new Tier 4 method is unique in that, instead of relying on emissions projections of NMOCs like Tiers 1-3, the Tier 4 method will use surface emissions monitoring with a trigger to install controls once a 500 ppm of methane threshold is reached or exceeded. 聽Landfills that exceed the 34 Mg/yr NMOC threshold under the earlier tiers (with an option to skip to Tier 3) will be able to avoid installing GCCS if surface emissions of methane are below 500 ppm for four consecutive quarters using Tier 4. 聽Importantly, landfills with modeled emissions of NMOCs exceeding 50 Mg/yr will not be able to use the Tier 4 methodology under the new rules.
- EPA Creates a Subcategory for 鈥淐losed Landfills鈥� and Eases the Burden to Remove, Exclude, and Cease Controls
- In an effort to protect certain landfills that are already on the downswing, EPA includes within the final Emission Guidelines a new subcategory for closed landfills. 聽Those landfills that close within thirteen months of the rule鈥檚 publication in the Federal Register will remain subject to the more favorable 50 Mg/yr threshold for determining when controls may be removed. 聽These landfills will also be exempt from certain initial reporting requirements.
- EPA further eases some of the burden for removing GCCS from a closed landfill. 聽One of the requirements to qualify for GCCS removal under the old regulations was that the landfill had to have operated the GCCS for 15 years. 聽EPA is now allowing landfills to demonstrate that it would be impossible to operate the GCCS for 15 years due to declining gas flows to satisfy this requirement. 聽A closed landfill owner looking to remove controls must also show that emissions from the landfill do not meet or exceed the 34 Mg/yr NMOC threshold in three successive emissions tests.
- Landfill owners looking to exclude areas from control, or cease control where a GCCS is already installed, may now use actual gas flow data to calculate whether they qualify. 聽Use of actual gas flow data is, however, limited to testing areas that are physically separated, e.g. lined off, from other parts of the landfill. 聽All areas where controls are excluded or have ceased must account for less than one percent of a landfill鈥檚 total NMOC emissions.
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