A strategy by WildEarth Guardians and Earthjustice to use the U.S. Supreme Court’s opinion in Massachusetts v. EPA to compel the EPA to issue New Source Performance Standards (NSPSs) for coal mines did not persuade the U.S. Court of Appeals for the D.C. Circuit.  The D.C. Circuit’s opinion confirmed EPA’s discretion to not undertake rulemaking if it provides a “reasonable explanation” for this decision. 

In Massachusetts v. EPA, the Supreme Court found that EPA’s refusal to regulate greenhouse gas (GHG) emissions had no basis in law.  In contrast, in WildEarth Guardians v. EPA, the D.C. Circuit states that the EPA explanation that it is simply prioritizing its rulemaking is in line with the Agency’s authority under the Clean Air Act (CAA).

Section 111

The case originated in June 2010 when WildEarth Guardians and other environmental groups petitioned the EPA to undertake rulemaking to add coal mines to the list of stationary source categories regulated under CAA Section 111.  The petitioners stated that coal mines met the criteria for inclusion under Section 111 (i.e., they emit air pollution that may reasonably be anticipated to endanger public health or welfare) and are also a source of 10.5 percent of U.S. emissions of methane, a GHG that contributes to climate change.

EPA’s priorities

In an April 2013 letter, the EPA denied the petition.  The Agency explained that because of limited resources it must focus on rulemaking that addresses sources that emit the most GHGs, specifically, the transportation sector and fossil-fuel power plants, which together account for 60 percent of U.S. GHG emissions; methane from coal mines comprises about 1 percent of U.S. GHG emissions. 

The EPA also explained that the budget of its Office of Air Quality Planning and Standards had been reduced by 12 percent between 2006 and 2012, that it had 45 nationally applicable stationary source rules due for review or promulgation by September 2014, and that it was facing challenges to 15 other recently issued rules.  The EPA letter emphasized that it was not refusing to regulate coal mines under Section 111 and that such an action was indeed possible in the future; rather, the Agency said it just will not do so at present. 

Massachusetts v. EPA

In their appeal to the D.C. Circuit, the petitioners argued that in Massachusetts v. EPA, the Supreme Court rejected the Agency explanation that budgetary constraints and higher priorities dissuaded it from undertaking rulemaking for GHG emissions from motor vehicles.  But the D.C. Circuit said the Supreme Court’s ruling considered much broader issues.  For example, the EPA claimed it possessed no CAA authority to regulate CO2 emissions from motor vehicles.  The Agency also argued that imposing such regulations would impede the U.S.’s ability to negotiate with key developing nations regarding GHG reductions and that regulating GHGs from motor vehicles would be an inefficient approach to the climate change issue. 

The Supreme Court rejected these explanations because they had nothing to do with the central issues in the case—whether GHG emissions contribute to climate change and whether the Agency has provided a reasoned justification for declining to form a scientific judgment. 

Reasonable explanation provided

In the current case, the D.C. Circuit emphasized that Section 111 states that the EPA must “from time to time” revise the list of stationary sources covered by the section and that the EPA administrator can take such action if “in his judgment [the source category] causes or contributes significantly to air pollution which may reasonably be anticipated to endanger public health or welfare.” 

“This language—‘from time to time’ and ‘in his judgment’—implies that the Administrator may exercise reasonable discretion in determining when to add a new source to the list of regulated air pollutants,” states the D.C. Circuit.  “In our view, the statute affords agency officials discretion to prioritize sources that are the most significant threats to public health to ensure effective administration of the agency’s regulatory agenda.”

The D.C. Circuit concluded that the EPA acted in accordance with its authority under Section 111 by providing a reasonable explanation for not regulating methane emissions from coal mines at this time.   

WildEarth Guardians v. EPA