On April 1, 2009, the Supreme Court decided Entergy Corp v. Riverkeeper, Inc., No. 07-588.
Electric power plants pose threats to the environment, among other ways, by sucking aquatic organisms into the plants' cooling-water-intake systems. Section 1326(b) of the Clean Water Act requires the Environmental Protection Agency (EPA) to establish regulations to "minimize" this potential harm that "reflect the best technology available." In carrying out this mandate, the agency imposed less restrictive standards on existing plants than it did for new facilities, based on its finding that retrofitting existing plants to meet the new plant standard would be unreasonably expensive and would require a significant reduction in the older plants' generating capacity. The EPA also allowed existing plants to seek variances from the regulations if they show that the costs of compliance "would be significantly greater than the benefits of complying … " Several environmental interest groups and states challenged these regulations, and the U.S. Court of Appeals for the Second Circuit held them to be inconsistent with the statutory requirement.
The Supreme Court reversed and upheld the regulations, holding that the EPA could properly consider the comparative costs and benefits of various means of achieving the statutory goal of "minimizing" the harm caused by power plant water-intake systems. The agency's approach reflected a reasonable interpretation of the statute and therefore was valid under the familiar administrative review standard of Chevron U.S.A. Inc. v. Natural Resources Defense Council, 467 U.S. 837 (1984). Both the statutory directive that regulations reflect "the best technology available" and the goal of "minimizing," rather than completely eliminating, adverse environmental impact gave the agency discretion to consider the costs of achieving various levels of protection.
Justice Scalia delivered the opinion of the Court, in which Chief Justice Roberts and Justices Kennedy, Thomas and Alito joined. Justice Breyer filed an opinion concurring in part and dissenting in part. Justice Stevens filed a dissenting opinion in which Justices Souter and Ginsburg joined.Download Opinions of the Court