Much of the naturally occurring radioactivity in fracking wastewater might be removed by blending it with another wastewater from acid mine drainage, according to a Duke University-led study published in the journal Environmental Science & Technology.
While fracking wastewater and acid mine drainage each pose environmental risks, blending them can bind some fracking contaminants into solids that can then be removed before the water is discharged back into waterways, explains Avner Vengosh, professor of geochemistry and water quality at Duke’s Nicholas School of the Environment and one of the study’s authors.
This makes it a win-win for industry and the environment, Vengosh says: “This could be an effective way to treat Marcellus Shale hydraulic fracturing wastewater, while providing a beneficial use for acid mine drainage that currently is contaminating waterways in much of the northeastern United States.”
Blending fracking wastewater with acid mine drainage also could help reduce the depletion of local freshwater resources by giving drillers a source of usable recycled water for the hydraulic fracturing process.
Limited available water resources, drought and increasing water-use demands from all segments of the economy is driving water management issues to the forefront of US oil and gas operations’ considerations and accounts for $8 billion in spending for water services in US fracking regions, according to a report from IHS.
An increasing number of oil and gas operations are reusing water. The practice is a boon to water companies that are helping drillers use less freshwater and dispose of less wastewater.
For instance, Fasken Oil and Ranch in West Texas now uses 90 percent recycled water for fracking, putting the company 10 percent away from its goal of not using any freshwater for fracking.