Hydraulic fracturing could have a huge impact on water quality

Hydraulic fracturing, or “fracking,” is a method of oil and gas extraction that has raised concerns over water quality. A team of scientists is now reporting that this controversial process also impacts water quantity by withdrawing millions of gallons of freshwater from nearby streams.

More than 5 million gallons of freshwater is used to fracture one gas well in the United States, which is enough water to fill seven Olympic-size swimming pools. Small streams, which are a major source of water for these operations, provide drinking water and shelter for many threatened marine species.

Despite the enormous amount of water being used for hydraulic fracturing, little is known about how much water can be sustainably taken from these natural sources. A research team led by Sally Entrekin focused its study on a gas field in Arkansas where more than 5,000 gas wells were drilled between 2004 and 2014 using hydraulic fracturing.

The streams in this particular study region supply drinking water to thousands of people, and are also home to 10 threatened marine species. Based on water usage and stream flow data, the researchers estimated the water stress that hydraulic fracturing might place on the streams.

The study revealed that freshwater usage for fracking could impact marine life in 7 to 51 percent of the streams, depending on the month. This percentage would drop if 100 percent of the wastewater were recycled, but 3 to 45 percent of the streams could still be affected.

The researchers have determined that improved monitoring and access to water withdrawal data are needed for the protection of the streams.

The study is published in the journal Environmental Science & Technology.

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By Chrissy Sexton, Earth.com Staff Writer