Supreme Court rejects Asarco challenge to EPA rule
Asarco LLC, which operates one of the three main U.S. copper smelters, was appealing a July decision by the D.C. Circuit Court of Appeals upholding the Environmental Protection Agency's new national ambient air quality standard for sulfur dioxide.
Without comment, the Supreme Court decided not to hear the appeal of Asarco, a unit of Grupo Mexico SAB.
(Reporting by Jonathan Stempel in Washington; Editing by Howard Goller and Gerald E. McCormick)