The fracking boom in North Dakota means more oilfield filter socks, used to filter wastewater at drilling sites, are seeing more usage. The problem is they often contain naturally occurring radioactive materials like radium.
In a normal case, the socks would end up disposed of at a proper disposal site, but that is not happening as they have turned up along the road, at an Indian Reservation, a city garbage can, and tucked under other waste trucked to landfills.
Fracking, or hydraulic fracturing, and lateral drilling have spurred an oil boom in western North Dakota so rapid the region has struggled to house and feed the influx of workers, according to the North Dakota Health Department. Monthly oil production in the state has increased from about 3 million barrels per month in 2008 to 25 million, according to the state’s Department of Mineral Resources.
Some of the water injected into deep shale formations during hydraulic fracturing returns to the surface as “flowback water.”
The catch is the flowback will contain the chemical additives used during fracking, which means it is an industrial wastewater that requires proper treatment and/or disposal, according to Cornell University’s Water Resources Institute. In addition, flowback will also contain chemical constituents associated with the shale, which may include high levels of salt, metals, organic compounds, and naturally occuring radioactive materials (NORM).
Filter socks’ job is to capture the solids in flowback water.
North Dakota prohibits disposal of waste that emits more than 5 picocuries per gram of radiation. Filter socks tested by a Williston, ND landfill operator emitted up to 47 pico curies per gram, the Sun reported.
The U.S. Environmental Protection Agency considers NORM a hazard mostly to workers at the site.
But it can be a hazard to the public as well. The state distributes a flyer to oilfield waste haulers that recommends appropriate locations for the disposal of oilfield wastes. The only ones listed that accept radioactive waste are in Colorado, Texas, and South Dakota.