The Supreme Court indicated Tuesday it could breathe new life into a federal rule requiring states to reduce power plant pollution from the South and Midwest that fouls the air in the eastern U.S.
Several justices suggested during a 90-minute argument that they believe the Environmental Protection Agency did not exceed its authority when it issued its cross-state air pollution rule in 2011. A divided federal appeals court panel invalidated the rule last year.
The EPA sought to reduce pollution from power plants in 28 states that drifts above states in the Northeast and Mid-Atlantic regions. Texas led 14 states and industry groups in challenging the rule. Most downwind states support it.
Justice Department lawyer Malcolm Stewart said the EPA is trying to be "an honest broker" between upwind and downwind states.
Sulfur dioxide and nitrogen oxide pollution from power plants can be carried long distances and the pollutants react with other substances to form smog and soot, which have been linked to illnesses. The cross-border pollution has prevented many cities from complying with health-based standards set by law.