PITTSBURGH — Last year, nearly 1,000 trucks hauling 15,769 tons of Marcellus Shale waste were stopped at Pennsylvania landfill gates after tripping radioactivity alarms.
The trucks were pulled to the side, wanded with hand-held detectors and some of the material was sent to laboratories for further evaluation. In the end, 622 tons were shipped to three out-of-state landfills specifically designed to dispose of hazardous and radioactive materials.
But most of the flagged waste was eventually allowed past the gates. It was safe enough to be buried along with other waste as long as it stays below the annual limit, the Department of Environmental Protection and landfill operators deemed.
The increase in radiation alarms going off at landfills has mirrored the growth in Marcellus Shale activity, and the DEP has launched a yearlong study of radioactive Marcellus waste to determine any risks involved in its transportation or disposal.
The radioactive material in Marcellus waste is naturally occurring. It’s mostly radium, a product of uranium decay, and it has been underground for millions of years in the Marcellus formation. Dredging earth and gas out of the ground brings up the radioactive elements.
Since 2002, all Pennsylvania landfills have been outfitted with radiation detectors following concerns about medical waste ending up in the municipal waste stream. All trucks arriving at the facilities pass through a gate topped with a sensor that takes a reading inches away from the top of the truck.
According to the DEP, Marcellus sludge is three times more likely to trip alarms than solid shale waste. Last year, 224 loads of drill cuttings elicited alarms at landfills, while 773 loads of sludge did the same. So far this year, 211 loads of sludge and 124 loads of drill cuttings tripped alarms, the DEP said.
But the number of times an alarm is tripped doesn’t tell the whole story.
In April, a truckload from Rice Energy arrived at Max Environmental’s Yukon Landfill in Westmoreland County and set off the alarm. The waste was deemed too radioactive.
The company shopped it around to a few landfills, but no one would take it, Mr. Poister said. Eventually, the truck went back to the source while arrangements were made to transport the waste to a specialized disposal site in Idaho.
“We’ve taken quite a bit of drill cuttings at our Yukon facility this year, and only one truck triggered the radiation alarm,” said Carl Spadaro, environmental general manager of the Yukon landfill. “Other landfills have had alarms triggered quite a bit.”
Yukon accepts about 90,000 tons of waste annually and just last month amended its permit to be able to accept waste that trips radiation alarms.
“We didn’t do this to bring in a lot of (radioactive) waste,” Mr. Spadaro said. “We did this to level the playing field.”
Yukon competes with two other landfills within a 5-mile radius.
“The biggest concern is exposure of a landfill worker during unloading and somebody who’s handling material,” Mr. Spadaro said.
The exposure level allowed at Pennsylvania landfills is a quarter of the EPA’s public radiation dose limit of 100 millirem per year.