Environmentalist groups hailed the Supreme Court’s decision in EPA v. EME Homer City Generation as a victory for the EPA and environmental protection.  It was surely a big victory for the EPA, but was it necessarily a victory for the environment? In the short run, the decision advances environmental protection by leaving in place a rule that will force greater emission reductions in upwind states. But the rationale of the decision gives the EPA leeway to adopt less-protective regulations in the future if the EPA were to determine that the reductions were too costly. Indeed, Justice Ruth Bader Ginsburg cited the threat of “overcontrol” of emissions as one reason for rejecting the strict textual reading of the Act adopted by the D.C. Circuit and urged by Justice Antonin Scalia in dissent.

The question in the case was whether the EPA’s Cross-State Air Pollution Rule limiting emissions from upwind states complied with the text of the Clean Air Act. Under the Act, states are obligated to prevent in-state sources of air pollution “from emitting any air pollutant in amounts which will . . . contribute significantly” to the nonattainment of federal air quality standards in downwind states.  This language would seem to require each upwind state to reduce emissions to the degree such reductions are necessary to ensure that sources in the upwind state are not interfering with air quality in downwind states.  Yet that’s not what the EPA did. Instead, the EPA based upwind-state emission reduction obligations on the cost of emission reductions.  This may be a good idea on policy grounds, particularly if one is more concerned with minimizing the cost of pollution control than with allocating obligations in proportion to each polluter’s relative contribution, but it is tension with the statutory text.  As Scalia wrote in dissent, Congress “specified quite precisely the responsibility of an upwind State” is “to eliminate those amounts of pollutants that it contributes to downwind problem areas.”  The D.C. Circuit likewise concluded that the Act bars the EPA from reallocating upwind states’ relative emission-reduction obligations based upon cost-effectiveness.

According to the Court in EME Homer, the EPA’s cross-state rule represented an “efficient and equitable solution” to the problem of interstate air pollution.

Efficient because EPA can achieve the levels of attainment, i.e., of emission reductions . . . at a much lower overall cost. Equitable because, by imposing uniform cost thresholds on regulated states, EPA’s rule subjects to stricter regulations those States that have done relatively less in the past to control their pollution.

That’s one way to characterize the result, but another is to say it is “inequitable” to impose emission reduction obligations on states out-or-proportion with their actual contributions to downwind air pollution.  And yet that is what the cross-state rule does in some cases. Brian Potts of Foley & Lardner  raises further questions as to whether the EPA’s rule is truly as “efficient and equitable” as the majority claims. (See also here.)

A final note.  According to Doug Kendall and Simon Lazarus of the Constitutional Accountability Center, the D.C. Circuit’s decision “shredded fundamental procedural constraints.” It was a key example of the D.C. Circuit’s alleged anti-regulatory agenda.  Interestingly enough, the merits of the procedural questions was the one thing upon which the Supreme Court was unanimous in EME Homer — and the court unanimously agreed with the D.C. Circuit.  Indeed, Ginsburg made rather quick work of these arguments in her majority opinion.