Category Archives: NAAQS

EPA Loses Another PSD Case: The Clean Air Act is “Extraordinarily Rigid”

In Sierra Club v. EPA, issued today, The Court of Appeals for the District of Columbia rejected EPA’s rules governing “significant impact levels” and “significant monitoring concentrations” for determining PSD permitting requirements for new sources of PM2.5.  Both the SIL and SMC provisions provided important exemptions from the PSD permitting regime. The Court ruled that […]