Ballooning bromide concentrations in the region’s rivers, occurring as Marcellus Shale wastewater discharges increase, is a much bigger worry than the risk of high radiation levels, public water suppliers say.

Unlike radiation, which so far has shown up at scary levels only in Marcellus Shale hydraulic fracturing wastewater sampling done at wellheads, the spike in salty bromides in Western Pennsylvania’s rivers and creeks has already put some public water suppliers into violation of federal safe drinking water standards.

Others, like the Pittsburgh Water and Sewer Authority, haven’t exceeded those limits but have been pushed up against them. Some have had to change the way they treat water.

Bromide is a salty substance commonly found in seawater. It was once used in sedatives and headache remedies like Bromo-Seltzer until it was withdrawn because of concerns about toxicity. When it shows up at elevated levels in freshwater, it is due to human activities. The problem isn’t so much the bromide in the river but what happens when that river water is treated to become drinking water.

Bromide facilitates formation of brominated trihalomethanes, also known as THMs, when it is exposed to disinfectant processes in water treatment plants. THMs are volatile organic liquid compounds.

Studies show a link between ingestion of and exposure to THMs and several types of cancer and birth defects.

“Our biggest concerns are about bromide, which has become a problem over the last six months or so,” said Stanley States, water quality manager with the Pittsburgh Water and Sewer Authority, which draws water from the Allegheny River for its 400,000 customers. “Trihalomethanes are strictly regulated because of the health risks. We’ve seen levels that are threatening the standards.”

The federal safe drinking water standard for THMs is 80 micrograms per cubic liter, and removing them from finished drinking water is difficult. Keeping bromide levels in raw water sources low is a much easier way to address the problem.

Mr. States said the elevated bromide levels in the river could be coming from municipal sewage treatment plants and brine treatment plants handling Marcellus Shale drilling and hydrofracking wastewater or from discharges by coal-fired power plants water discharges. He said four municipal sewage facilities and four brine treatment plants are handling and discharging Marcellus Shale wastewater upriver from Pittsburgh’s drinking water intake pipe in Aspinwall.

“Something’s changed and it could possibly be related to the treating of Marcellus Shale drilling wastewater,” Mr. States said. “There will be a lot more Marcellus Shale wells operating in the region before there are a whole lot less and our concern is in providing safe drinking water. We’re not anti-Marcellus Shale. We’re anti-bromide.”

Pittsburgh is not alone. The Wilkinsburg-Penn Joint Water Authority issued a notice to its customers in January informing them of the bromide problem and said it was necessary to change its water treatment methods to stay in compliance with state and federal drinking water standards.

“Due to the sudden increase in bromide concentration in the Allegheny River, all water suppliers are beginning to have a problem controlling this trihalomethane formation,” the authority wrote on its Web page. “All water purveyors on the Allegheny River System are working together to try and find out the source of the elevated bromide levels.”

Mr. States said a study is under way on the Allegheny River and its tributaries to identify sources of bromide in the river.

The Department of Environmental Protection is participating in that river sampling study and another in the Monongahela River watershed.

Katy Gresh, a DEP spokeswoman, said the department plans to order the industrial brine plants, sewage treatment facilities and coal-powered power plants on the rivers to conduct sampling at their discharge pipes.

“We will get and review those results,” Ms. Gresh said. “If we can control the largest contributors, that will help solve the problem.”

Jeanne VanBriesen, a Carnegie Mellon University professor of civil and environmental engineering, said testing there showed an unusual spike in bromide levels in July and August. Although they’ve tapered a bit since then, they remain higher than normal, said Ms. VanBriesen, who has been studying water quality in the Monongahela River since fall 2009.

She said the two biggest sources of bromide in the watershed are Marcellus wastewater from sewage treatment facilities and wastewater from new smokestack scrubbers at coal-fired power plants. The plants cannot remove the bromide in wastewater.

Bromide levels vary in discharges from both sources, but bromide is generally found at higher concentrations in Marcellus wastewater.

“It’s difficult to make a definitive statement about where it’s all coming from, but we do know it’s going into our drinking water treatment plants and affecting the treatment of our water,” Ms. VanBriesen said. “The most logical way to fix that is to reduce the amount of bromide in the rivers and creeks.”

Marcellus Shale drilling and hydraulic fracturing operations use an average of 4 million gallons of water to drill and “frack” each well. The drilling industry says it recycles approximately 70 percent of the wastewater from its well fracking operations, but millions of gallons are still funneled through 11 sewage treatment facilities and five brine treatment plants, then discharged into the state’s rivers and streams.

Together, the eight facilities on the Allegheny and its tributaries are allowed to discharge an average of 1.5 million gallons of Marcellus drilling wastewater and hydraulic fracturing fluid a day, according to state Department of Environmental Protection records. Marcellus discharges from three treatment facilities on the Monongahela River total 185,000 gallons a day. Another 650,000 gallons a day flow into the Ohio and its tributaries.

Drilling companies and the Marcellus Shale Coalition, an advocacy and lobbying organization representing most of the companies doing shale gas drilling in Pennsylvania, said the industry isn’t to blame for higher bromide levels.

“When you look at the amount of Marcellus Shale wastewater that is being discharged it’s low” compared to the river flows, said Matt Pitzarella, a spokesman for Range Resources. “So those [bromide] increases are not an impact of Marcellus Shale.” Range Resources recycled 90 percent of its wastewater last year and has set a goal of 100 percent for 2011.

“We certainly see this as a non-Marcellus issue,” said Steve Forde, a shale coalition spokesman, who cited a 2010 U.S. Geological Survey study that noted higher bromide levels nationwide, especially in urban areas. “Road salt use has been identified as one of the culprits for that.”

Ms. VanBriesen said that’s not likely because road salt contains more chloride and little bromide, and her water testing didn’t find a corresponding spike in chloride levels. Plus the bromide spike in the rivers first occurred in the summer.

“So to implicate road salt, well, I wouldn’t buy that,” she said. “The bromide spike happened in July and August when you wouldn’t be applying road salt. So that wasn’t a factor.”

Whatever the origin of the bromide spike, Jerry Schulte, manager of source water protection for the Ohio River Valley Water Sanitation Commission, said bromide is “absolutely an issue” for water treatment plants.

“We’ve identified bromide as a compound of concern,” Mr. Schulte said, adding that ORSANCO’s triennial review of pollution control standards in April will focus on developing a new, first-time standard for bromide in the watershed.

Discharges of bromides and bromide levels in rivers or streams are not now regulated by ORSANCO or by the U.S. Environmental Protection Agency.

The Josephine brine treatment facility, also known as Franklin Brine, on Blacklick Creek in the Allegheny’s watershed, discharges an average of 120,000 gallons a day of Marcellus wastewater that, at peak levels, contains high concentrations of bromide, chlorides and total dissolved solids, according to sampling done by the University of Pittsburgh’s Center for Healthy Environments and Communities.

“There’s pretty high bromide going into the creek. Certainly it is a public health threat,” said Conrad Dan Volz, director of the Center for Healthy Environments and Communities. “And to remove brominated THMs, that’s going to break the bank for public water systems.”

Water treatment plants can get around the bromide problem by changing their treatment methods — substituting chloramines for the chlorides they normally use in the disinfection process. That’s what the Wilkinsburg-Penn water authority did.

The chloramines produce different, less toxic, treatment byproducts, but those can produce other problems, including causing lead and copper to leach out of old water pipelines and into drinking water as happened in Washington, D.C., when it made such a switch in 2000.

Ms. VanBriesen said water utilities making such a change can add phosphate to their finished water to prevent lead from leaching out of the pipes.

Another way to avoid THMs, she said, is to change the way water utilities mix, aerate and store their finished water, and a number of suppliers are considering that.

One water treatment facility that has had problems with keeping THM concentrations in finished water below the 80 parts per billion federal standard is Beaver Falls, in Beaver County, which was required to notify its 50,000 customers in 22 municipalities of the problem for the first three quarters of 2010.

The authority changed its treatment methods, from chlorine to chloramines, which don’t form THMs, at a cost of approximately $15,000 last year. That allowed the water supplier to meet the standard for the last three months of the year, said Jim Riggio, general manager of the water system.

Although testing done by the state DEP hasn’t been able to pinpoint a cause of the higher bromide levels in the Beaver River, Mr. Riggio said they coincided with upriver discharges of treated Marcellus Shale fracking wastewater.

“We went from non-detectable levels of bromide to increased levels a couple of years ago,” Mr. Riggio said. “When I see the whole frack water thing taking off and the same time we start to have problems, well, until you can tell me different, that’s what I assume it is. And it seems like a lot of the water suppliers on the Beaver and Mon rivers had similar problems to what we did.”