(June 20, 2016, 7:18 AM EDT) -- OKLAHOMA CITY — A federal judge in Oklahoma on June 8 denied a group of residents’ motion to amend their complaint and add 82 plaintiffs in a groundwater contamination lawsuit against Halliburton Energy Services Inc. (HESI), ruling that adding plaintiffs at this stage of the case would prejudice the defendant (Mitchell L. McCormick v. Halliburton Energy Services Inc., No. 11-01272, W.D. Okla.)....