"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."