APPALACHIAN POWER COMPANY, et al., Petitioners, v. ENVIRONMENTAL PROTECTION AGENCY, Respondent. Commonwealth of Pennsylvania, Department of Environmental Protection, et al. Intervenors. Nos. 99-1268, 99-1270, 99-1274, 99-1276, 99-1277, 99-1279 to 99-1281, 99-1286, 99-1287, 00-1169, 00-1187, 00-1189 to 00-1192 and 00-1194.United States Court of Appeals, District of Columbia Circuit.Argued March 23, 2001. Decided June 8, 2001. Page […]