Residents near the Marcellus Shale Gas Field have long been wondering whether their water is safe to drink.

A new study from Duke University is likely to further stoke fears.

Geochemists have found dangerous levels of radioactivity and salinity at a fracking disposal site near Blacklick Creek, which feeds into water sources for Pittsburgh and other western Pennsylvania cities.

The Duke scientists spent two years, from 2010 to 2012, taking soil samples upstream and downstream from the Josephine Brine Treatment Facility in Indiana County, PA. What they found was striking.

Even after waste water was treated at the plant to remove dangerous chemicals, radiation was detected far above regulated levels.

The treated water had Radium levels 200 times greater than control water from the area, said Avner Vengosh, professor of geochemistry and water quality at Duke University’s Nicholas School of the Environment and one of the primary authors of the study.

In addition, the team found high levels of bromide in the water, a particularly alarming development. Drinking water plants use chlorine and ozone to turn river water into drinking water. When those chemicals react with bromide, they produce highly toxic byproducts.

That has yet to happen, according to Vengosh, but it is a dangerous possibility.

The wastewater that the facility is treating is a byproduct of fracking, the controversial method of injecting chemicals, sand and water into deep underground rock formations to release oil and natural gas.

Wastewater is a highly saline and radioactive fluid that returns to the surface during the fracking process.

“Each day, oil and gas producers generate 2 billion gallons of wastewater,” Duke Professor Rob Jackson said.

“They produce more wastewater than hydrocarbons. That’s the broader implication of this study. We have to do something with this wastewater.”

Approximately 70% of the fracking industry's wastewater in Pennsylvania gets reused to do more fracking.

Between 8% and 20% of the wastewater is delivered to treatment plants such as Joseph Brine. The remainder is disposed of using other methods. The map below shows the Marcellus Shale formation and the surrounding areas. Red squares indicate Oil and Gas Pollution Control Facilities. The black square is the Josephine Brine Treatment Facility: Avner Vengosh et all While the Duke University study only focuses on a single wastewater treatment plant, Vengosh believes that hundreds of disposal sites could be similarly affected. If the problem isn’t fixed, the chemicals could end up in insects, small animals, fish, and drinking water.

Ann Seamonds of Fluid Recovery Services, which operates the Joseph Brine Treatment Facility, sent a lengthy response to Energy In Depth. Her main contention is that Brine stopped processing wastewater from Marcellus Shale in May 2011 and thus the study is flawed.

But the Duke scientists remain positive the contaminants are the result of fracking, because the water contains the same chemical signature as rocks in the Marcellus Shale formation.

Some progress has been made on the issue.

In May, Fluid Recovery Services signed an agreement to not accept or discharge wastewater from formations such as Marcellus Shale until it has installed technology to remove the radiation compounds, metals and salts.