Editing McClain County, Oklahoma (section)

==Controversy==

===Contaminated water supply===
In 2010, the EPA ordered local water utilities to begin the first nationwide tests for hexavalent chromium 6 (AKA The Erin Brockovich Chemical). From 2013 to 2015, utilities took more than 60,000 samples of drinking water and found chromium-6 in more than 75 percent of them.<ref>{{Cite web|url=http://www.epa.gov/dwucmr/occurrence-data-unregulated-contaminant-monitoring-rule#3|title=Occurrence data unregulated contaminant monitoring rule #3}}</ref> The Purcell water supply tested positive for an average of 11.53ppb, 577 times the original recommendation from the scientists at the respected and influential California Office of Environmental Health Hazard Assessment of 0.02ppb.<ref>{{Cite web|url=http://www.oehha.ca.gov/water/phg/072911Cr6PHG.html|title=U.S. EPA, Occurrence Data for the Unregulated Contaminant Monitoring Rule. April 2016.}}</ref>