The AP is reporting that yesterday researchers at Carnegie Mellon University presented at a CMU conference new but preliminary data that showed bromide levels on the Mon river had declined but were above background readings and still a concern. http://www.centredaily.com/2011/11/03/2973525/mon-river-pollutant-level-down.html#lxzz1cgHazEeT. The AP states that the researchers would not now release the newest data, because the study is preliminary and undergoing review.
Bromide research conducted by Carnegie Mellon University in 2010 and released in early 2011 prompted Secretary Krancer to request that gas drilling companies no longer take gas drilling waste to municipal water treatment systems that did not have the ability to treat wastewater for total dissolved solids of which bromide is a part. DEP states in the AP story that "nearly all" drilling companies no longer discharge drilling wastewater at treatment plants.
Other than drilling wastewater, there are multiple other sources such as industrial plants and coal plants for total dissolved solids discharges of which bromide can be a part to the historically tds stressed Mon river. TDS readings on the Mon River for many years and well before Marcellus wells were drilled have had elevated levels of TDS, though below levels established by the Safe Drinkig Water Act, except during a spike from October to December 2008. DEP in 2010 recommended to EPA that the EPA list the Mon river as being impaired by sulfate pollution. Sulfates are also a part of TDS.
Bromide itself is not toxic, but can react with certain chemicals sometimes used at drinking water plants that could create a harmful compound. Consequently, drinking water systems monitor bromide levels in their intake water to determine whether bromide is at concentrations that could lead to reactions that could compromise drinking water safety. If bromide levels are at such levels, drinking water systems change the chemical treatment process of the water to prevent the reactions that create the harmful compound.