The horizontal drilling method called hydraulic fracturing helps the United States produce close to 4 billion barrels of oil per year, rocketing the U.S. to the top of oil-producing nations in the world.
The highly profitable practice comes with a steep price: For every barrel of oil, oil and gas extraction also produces about seven barrels of wastewater, consisting mainly of naturally occurring subsurface water extracted along with the fossil fuels. That’s about 2 billion gallons of wastewater a day. Companies, policymakers and scientists are on the lookout for new strategies for dealing with that wastewater. Among the most tantalizing ideas is recycling it to irrigate food crops, given water scarcity issues in the West.
A new Colorado State University study gives pause to that idea. The team led by Professor Thomas Borch of the Department of Soil and Crop Sciences conducted a greenhouse study using produced water from oil and gas extraction to irrigate common wheat crops. Their study, published in Environmental Science and Technology Letters, showed that these crops had weakened immune systems, leading to the question of whether using such wastewater for irrigation would leave crop systems more vulnerable to bacterial and fungal pathogens.
“The big question is, is it safe?” said Borch, a biogeochemist who has joint academic appointments in the Department of Chemistry and Department of Civil and Environmental Engineering. “Have we considered every single thing we need to consider before we do this?”
Read more at Colorado State University