DUQUESNE LIGHT COMPANY ET AL., PETITIONERS, v. ENVIRONMENTAL PROTECTION AGENCY, RESPONDENT. No. 72-1542.United States Court of Appeals, Third Circuit.Argued May 12, 1975. Decided August 21, 1975. Page 1187 David McNeil Olds, John McN. Cramer, Robert M. Walter, Reed, Smith, Shaw Page 1188 McClay, Pittsburgh, Pa., for petitioners. Wallace H. Johnson, Asst. Atty. Gen., Edmund B. […]