State environmental investigators are trying to determine the source of a chemical that Carnegie Mellon University researchers say is responsible for carcinogens in drinking water from the Monongahela River.
Department of Environmental Protection workers are investigating whether coal, power and oil- and gas-drilling industries are to blame for unsafe levels of bromide in the river, said Ron Schwartz, assistant director of DEP's southwest region, at a daylong symposium Thursday at CMU. It could take weeks or months to determine who is at fault, he said.
"There's very little, if anything, the (water) utilities can do to remove that from their water," Schwartz said. "The key is to remove it from the source points."
There is no significantly increased risk of cancer from the water right now, he said.
That could change if the bromide problem persists, said Jeanne VanBriesen, a CMU professor and director of Water Quality in Urban Environmental Systems, a research center at CMU.
The Monongahela River basin provides drinking water for about 1 million people in Pennsylvania and West Virginia.
In July and August, VanBriesen's research team found bromide combined at higher levels than usual with sanitizing chemicals in drinking water from the Mon, creating carcinogenic byproducts. If the trend continues, levels of carcinogens could remain elevated for months, violating federal safe drinking water standards, she said.
Bromide is found naturally in seawater and underground rock formations and is even in Mountain Dew. It also is used as a flame retardant for upholstery.
If bromide is in the river water when the water is chlorinated, it can combine with chlorine to create a disinfectant byproduct, VanBriesen said.
Those byproducts can cause cancer, but they are common in drinking water in trace amounts. Federal regulations require they be kept at minimal levels.
Cycles of elevated pollution have plagued the Mon since 2008, and water utilities have reported higher-than-expected levels of bromide during peak times, VanBriesen said. Her team began its research a year ago using water monitors throughout the Mon basin, and bromide levels stayed low and steady until spiking this summer, she said.
VanBriesen began searching for bromide in a quest to discover whether Marcellus shale gas drilling was polluting the river. Bromide and gas come up together from deep shale deposits, making it a signature component of wastewater from shale drilling, according to experts.
Power plants also use the chemical to clean their cooling towers, she said.
The gas drilling industry is not likely at fault because the state since 2008 has imposed strict limits on how companies dispose of wastewater, said Matt Pitzarella, spokesman with Range Resources, a Fort Worth-based gas company with an office in Cecil.
Doug Colafella, a spokesman for Allegheny Energy, which owns three power plants on the Mon, declined to comment.