Mealey's (May 6, 2016, 2:16 PM EDT) -- OKLAHOMA CITY — The three hydraulic fracturing companies being sued by the Sierra Club seeking to stop the injection of fracking waste into the ground on April 25 filed a brief in Oklahoma federal court contending that the case should be dismissed because the district court lacks primary jurisdiction (Sierra Club v. Chesapeake Operating LLC, et al., No. 16-134, W.D. Okla.)....