On Monday, EPA promulgated amendments to its “Exceptional Events” Rule. The rule is important, particularly in the Western states, and most particularly in connection with EPA’s latest iteration of the ozone NAAQS. EPA’s most significant revision was to eliminate the requirement that state air agencies demonstrate that, “but for” the exceptional event, the state or relevant area would have complied with the applicable NAAQS. The change is important for two reasons. … More