Bromide down in Mon, still elevated in Allegheny
Researchers at Carnegie Mellon University say a water quality problem in the Monongahela River that may have been linked to Marcellus shale natural gas drilling is going away.
Bromide, which can cause cancer in drinking water, has declined in the Mon, apparently coinciding with a voluntary ban on disposing gas drilling wastewater, researcher Jeanne VanBriesen said Thursday. State officials cited her research in asking for the ban in the spring of 2011.
However, success has not been universal in Western Pennsylvania, said Melissa Rubin, spokeswoman at the Pittsburgh Water & Sewer Authority. Its scientists have still found elevated levels of bromide in the Allegheny River, the authority's source for its drinking water, she said.
“The pollution in the Allegheny River is just as bad as it always was,” Rubin said. “So although this is a wonderful thing for the utilities that pull water from the Mon River, that's just simply not — unfortunately — it's not the case for those that pull from the Allegheny.”
Though not considered a pollutant by themselves, bromides combine with the chlorine used in water treatment to produce compounds that can cause cancer.
Preliminary data from this year showed that levels of salty bromides have declined significantly in the Monongahela when compared to 2010 and 2011, VanBriesen said. In many cases the bromides were at undetectable levels in the river this year, and in general they returned to background, or normal levels.
VanBriesen and some local water authorities first noticed a spike in the summer of 2010, sparking an investigation from state environmental regulators. After they asked drillers and public wastewater treatment plants to stop dumping their partially treated wastewater into surface water in 2011, bromide levels didn't initially go down, VanBriesen had said a year ago, before her latest findings.
That had led to drilling companies and power plants — both of which can produce bromide as waste — to deny they were responsible.
Trib Total Media staff writer Timothy Puko and The Associated Press contributed to this report.