(May 4, 2021, 1:42 PM EDT) -- GREAT FALLS, Mont. — Environmental groups on May 3 sued the U.S. Army Corps of Engineers and its commanding general in Montana federal court, contending that the Corps violated federal laws, including the Clean Water Act (CWA), when it issued a permit for pipeline projects to carry hydraulically fractured oil and gas “without adequately assessing its significant direct, indirect, and cumulative environmental effects.”...