A new Duke University study finds that thousands of saltwater and frack flowback spills throughout the oil patch have left a legacy of toxic contamination. Bismarck Tribune, North Dakota. Apr 28 2016 http://bismarcktribune.com/news/state-and-regional/study-indicates-lingering-saltwater-contamination-in-oil-patch/article_d62aaa65-c9ff-5ddb-bb40-8e0983efdde3.html