This is an excerpt from EERE Network News, a weekly electronic newsletter.

October 07, 2009

EPA Aims to Limit Greenhouse Gas Regulations to Large Facilities

The U.S. Environmental Protection Agency (EPA) is proposing a rule that would limit future greenhouse gas (GHG) regulations under the Clean Air Act to large industrial facilities emitting the equivalent of 25,000 tons or more of carbon dioxide annually. The rule will also require a permit when major emitters of GHGs make modifications that increase their GHG emissions. That permit requirement will be triggered with emission increases equivalent to somewhere between 10,000 and 25,000 tons of carbon dioxide. The EPA isn't sure where exactly to set this "significance level" for modifications, and it is seeking comments on the best value to use. The proposed rule will limit GHG regulations to facilities such as power plants, refineries, and factories, which produce nearly 70% of U.S. GHGs.

The EPA is currently proposing to regulate GHGs from cars and light trucks under the Clean Air Act, as part of joint rule on fuel economy with the National Highway Traffic Safety Administration. The EPA intends to finalize that regulation in the spring of 2010, and once that happens, GHGs will be treated as pollutants under the Clean Air Act. That would automatically trigger regulations for relatively small GHG emitters, a situation that the EPA is intending to avoid. Under the proposed rule, small and medium-sized businesses such as farms and restaurants, as well as many other facilities, would not be subject to GHG regulations. As noted in the proposed EPA rule, allowing GHG regulations to apply to relatively small emitters would cause state permitting authorities to be "paralyzed by permit application in numbers that are orders of magnitude greater than their current administrative resources could accommodate."

The proposed "tailoring" rule addresses six greenhouse gases: carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride. With the proposed industrial emissions thresholds, EPA estimates that 14,000 large sources would need to obtain operating permits that include GHG emissions because they exceed the 25,000 ton threshold. Most of these sources are already subject to clean air permitting requirements because they emit other pollutants. In addition, 400 new sources or modified sources would be subject to review each year for GHG emissions. Under the Clean Air Act, the EPA will ensure that these new or modified sources are using the best available control technologies and energy efficiency systems to minimize GHG emissions. The EPA plans to develop sector- and source-specific guidance that will help permitting authorities and industrial facilities better understand GHG emissions for each type of facility, methods for estimating those emissions, available GHG measurement and monitoring techniques, and strategies to minimize GHG emissions. The EPA also plans to revisit its thresholds after five years to see if they can be lowered.

Under the proposed rule, the EPA estimates that about 3,000 GHG emitters will be newly subject to Clean Air Act permit requirements, and most of those will be municipal landfills. Landfills account for about 23% of human-caused methane emissions in the United States, and the new regulations are likely to encourage the capture of landfill methane emissions and their use as a renewable energy source. The proposed rule, announced by the EPA on September 30, will be open for public comment for 60 days once it has been published in the Federal Register. As of October 6, it had not yet been published. See the EPA press release, a fact sheet on the proposed rule, and the full proposal (PDF 533 KB). Download Adobe Reader.