The Arizona Chamber of Commerce & Industry will be in court today arguing against an EPA regulation that significantly threatens Arizona industry. The case, styled Commonwealth of Kentucky v. U.S. EPA, will be heard by the D.C. Circuit Court of Appeals and concerns EPA’s regulation of fine particulate matter. The Chamber is part of a coalition of 10 trade associations plus Arizona Speaker of the House Ben Toma and Arizona Senate President Warren Petersen. Additionally, Kentucky leads a group of 25 states who are also challenging the regulation in parallel. Though the two coalitions make slightly different arguments to the court, all challengers agree that EPA has acted beyond its authority in issuing the new regulation.
Fine particulate matter—also known as “PM 2.5”—consists of particles with diameters less than or equal to 2.5 micrometers. The Clean Air Act gives EPA authority to regulate PM 2.5, but, in an unprecedented move, EPA lowered an existing standard, already one of the lowest in the world, by 25%, without going through the statutory process required by the Act. The new standard will likely impose a burdensome permitting process and expensive control measures for industries in three of Arizona’s counties.
If not struck down, Maricopa, Pinal, and Santa Cruz counties are all in danger of exceeding the new PM 2.5 standard despite little evidence that Arizonans can meaningfully reduce PM 2.5 levels. In Maricopa and Pinal Counties, for instance, the top contributor to PM 2.5 are wildfires that largely occur on federal land. Arizona’s climate and geography also increase PM 2.5 levels regardless of what humans do. There is also little or conflicting evidence that lowering the standard will result in meaningful public health improvements.
The revised standard is not just bad policy; it is illegal. The Clean Air Act creates a very specific statutory process when setting the national standard for PM 2.5 (and other pollutants). At least every five years, EPA is required to conduct a “thorough review” of air quality criteria and set a new national standard. EPA last did this in 2020 and determined that the standard should remain unchanged from the 2015 standard.
The 2020 review was consistent with the Clean Air Act’s requirement of a “thorough” review. In deciding not to lower the standard, EPA explained that the scientific evidence since 2015 did not call the standard into question and there was considerable uncertainty around whether public health would improve from lowering the standard. EPA emphasized that epidemiological studies were too ambiguous and limited to support lowering the standard.
Nevertheless, a year later in 2021, EPA inexplicably announced that it would “reconsider” the 2020 decision. That reconsideration culminated in the lowering of the PM 2.5 standard, effective in March of this year. In doing so, EPA took the radical position that it could not consider costs, attainability, and technological feasibility. It also admitted it did not conduct the required “thorough review” and instead only “partially reopen[ed]” the review.
Such a maneuver is illegal, and the Chamber looks forward to the court scrutinizing EPA’s decision.
Nate Curtisi is an attorney with the Arizona Chamber of Commerce & Industry