On Tuesday, the D.C. Circuit Court of Appeals affirmed EPA’s update of its hexavalent chromium MACT rule.  Suffice it to say that this was a little easier than review of the power plant MACT rule.

The Court rejected both industry and environmental group challenges, in what was largely a straightforward application of Chevron.  The opinion is nonetheless useful in laying out what EPA must have in the record to justify ratcheting down MACT standards.

The key element was the Court’s rejection of the industry position that EPA must identify how each specific “development” that has occurred since the prior promulgation of the applicable MACT standard is tied to the new standard:

It suffices for EPA to assess and discuss the collective impact of the developments it has identified, and to revise standards appropriately in light thereof. The agency explained that it had examined what emissions levels could be achieved using various add-on control devises and fume suppressants, including developments the agency had previously identified. EPA went on to provide details regarding the costs and emissions reductions identified, and evaluated in the course of arriving at its conclusion that specified, best-available control technologies could cost-effectively meet more stringent emissions standards. The statute does not require EPA to identify a nexus between each distinct development and the revised standards. EPA’s decisionmaking was sufficiently clear and rational.

Game over.