U.S. EPA yesterday ended the latest chapter in the turbulent drilling dispute in Dimock, Pa., finding that contaminant levels in its water show no health threat and no connection to hydraulic fracturing chemicals. The action, however, does not change state officials' case against Cabot Oil and Gas for contaminating water wells in the community with methane. The Pennsylvania Department of Environmental Protection still has not cleared Cabot to drill in areas of Dimock Township where it ordered wells shut down in 2009. That case focused on poor well construction, not problems with fracturing.