(October 30, 2018, 9:14 AM EDT) -- CINCINNATI — Two environmental groups in an Oct. 22 petition ask the Sixth Circuit U.S. Court of Appeals for an en banc rehearing of a case in which they claim that the Tennessee Valley Authority (TVA) violated the Clean Water Act (CWA) by discharging coal ash waste from its wastewater treatment system that reached navigable waterways through groundwater (Tennessee Clean Water Network, et al. v. Tennessee Valley Authority, No. 17-6155, 6th Cir.)....