The U.S. Fifth Circuit Court of Appeals Upholds the EPA’s Determination that Martin Lake Coal Plant Does Not Meet National Air Quality Standards

The Sierra Club Environmental Law Program’s efforts to model air pollution levels around major coal plants recently saw a decisive affirmation in the form of a U.S. Fifth Circuit Court of Appeals ruling. On January 11, the Fifth Circuit upheld the U.S. Environmental Protection Agency’s determination, based on Sierra Club’s modeling, that air quality in the area surrounding Luminant’s Martin Lake Coal Plant (Martin Lake) does not meet national air quality standards. 

Nearly all sulfur dioxide (SO2) pollution in the U.S. comes from a relatively small number of large coal-burning power plants, most of which don’t use air quality monitors to measure actual SO2 emissions. Exposure to SO2, even for short periods of time, can cause respiratory and cardiovascular illness, aggravate asthma, and even kill. So Sierra Club’s Environmental Law Program developed and implemented a plan to conduct air dispersion modeling for several of the largest coal plants in the country, to inform EPA’s SO2 designations for those areas. 

EPA relied on Sierra Club’s air dispersion models to determine that the Martin Lake area was in nonattainment with national SO2 standards. Luminant challenged the use of Sierra Club’s models over their own. The key issue in the case was whether EPA arbitrarily relied on Sierra Club’s air quality modeling, which followed EPA protocols and regulations, and properly rejected Luminant’s competing modeling, which included unapproved model adjustments and relied on speculative future emission reductions. Because of the Environmental Law Program’s work, Martin Lake will be required to significantly reduce harmful SO2 pollution. 

Sierra Club was represented in this case by Environmental Law Program attorney Joshua Smith together with co-counsel from Earthjustice. Environmental Law Program attorneys Zachary Fabish and Kristin Henry played a critical role in planning Sierra Club’s modeling efforts and coordinating the legal and public advocacy strategy to persuade the EPA to evaluate and designate nonattainment areas across the country, not just at Martin Lake.