"The Bluestone River that straddles the Virginia-West Virginia border has long been a popular trout-fishing spot, as well as a source of drinking water for nearby towns.
So Virginia environmental officials were stunned when routine sampling turned up something disturbing: Carp in the river were loaded with industrial compounds called polychlorinated biphenyls, or PCBs.
Seeking to unravel the mystery, they followed the river all the way up to the entrance of a rural cave in West Virginia.
The groundwater inside Beacon Cave had PCB concentrations that “were just astronomically high,” said Nick Schaer, a geologist with the West Virginia Dept. of Environmental Protection who helped conduct the sampling. “We were getting numbers many times higher than health-based limits.”
The likely suspect sits directly over the cave--a long-abandoned electric manufacturing plant."