This case is about how the EPA establishes standards for maximum achievable control technology (MACT) which is used to minimize the emission of pollutants into the air. It arose in the context of a new regulation on emissions of hazardous air pollutants from electric utilities, as well as industrial-commercial-institutional steam generating units. The 2012 "Utility MACT" regulation adopts a methodology that has broad implications for industries subject to existing MACT standards that may be revised, or new standards yet to be developed.
The NAM filed an amicus brief arguing that the EPA erred in adopting a "pollutant-by-pollutant" approach. Under that approach, the EPA cherry-picks emissions data from multiple sources and sets a MACT floor based on whatever source is deemed the "best" for each individual pollutant. This often means there is a different best performer for each pollutant, and no single source of emissions will be able to achieve the regulatory requirement. The NAM believes that these measurements need to be made from producers operating under practical conditions -- not individually measuring pollutants and not from sources ideally positioned to limit their pollution, as the EPA argues. The EPA's approach is like asking a decathlon champion to be able to win not only the overall decathlon, but all of the individual events as well.
In addition, we argued that the EPA must give meaningful consideration to costs in determining whether a particular standard is achievable. The Clean Air Act requires that the level of pollution reduction that the EPA specifies be achievable, and its methodology will severely curtail or eliminate operations. Some vendors are unwilling to offer guarantees that their pollution control technology will meet the new standards, and financing of new projects is jeopardized.
On 9/12/2012, the court ordered this case to be held in abeyance pending reconsideration of the new source standards now under way at the EPA. The agency stated that it intends to complete the reconsideration by March 2013. It said it would reconsider "measurement issues related to mercury and the data set to which the variability calculation was applied when establishing the new source standards for particulate matter and hydrochloric acid." See 77 Fed. Reg. 45968 (Aug. 2, 2012).
The case was settled in 2014 by stipulated agreement.