"Study Finds Lower Bromide Levels in Mon, But Not in Allegheny"
"Salty bromide concentrations in the Monongahela River, which had risen in 2009 and 2010 due, at least in part, to discharges of Marcellus Shale gas drilling wastewater by sewage treatment plants, returned to normal levels in 2011 and this year, according to a Carnegie Mellon University river monitoring study."
"The findings are good news for municipal water suppliers concerned that the higher levels of bromide, a nontoxic salt compound, were reacting with chlorine in the water disinfection process to produce higher than healthy concentrations of a carcinogen, trihalomethane, in the finished water supplied to their customers.
Eleven public water utilities use the Monongahela River to supply water to about 1 million people."Source: Pittsburgh Post-Gazette, 11/13/2012