Scientists: Fracking Wastewater Poses Threat To Drinking Water

פורסם: 26 בספט׳ 2014, 7:33 על ידי: Sustainability Org   [ עודכן 26 בספט׳ 2014, 7:35 ]
by Emily Atkin Posted on September 25, 2014
A jar holding waste water from hydraulic fracturing is held up to the light at a recycling site in Midland, Texas, Sept. 24, 2013.

A jar holding waste water from hydraulic fracturing is held up to the light at a recycling site in Midland, Texas, Sept. 24, 2013.

CREDIT: AP Photo/Pat Sullivan

Every year, hundreds of billions of gallons of wastewater are produced by fracking operations across America. Some of that water gets stored in manmade ponds, some of it is injected underground, and some of it is treated and put back into rivers.

For the people whose drinking water systems are downstream of those rivers, scientists have some bad news.

New peer-reviewed research from Stanford and Duke University scientists shows that even when fracking wastewater goes through water treatment plants, and is disposed of in rivers that are not drinking water systems, the treated water still risks contaminating human drinking water. That’s because there are generally drinking water systems downstream of those rivers, and treatment plants aren’t doing a good job of removing contaminants called halides, which have the potential to harm human health.

The scientists say halides — which are salts like bromide, chloride, and iodide — are often found in fracking wastewater, and the concern about them is that their presence in the water can promote the formation of something called “disinfection byproducts,” or DBPs. These chemicals — trihalomethanes, haloacetic acids, bromate, and chlorite — are formed when the disinfectants used in water treatment plants react with halides, according to the Environmental Protection Agency.

Published in the journal Environmental Science and Technology and released by the American Chemical Society on Wednesday, the research showed that toxic compounds formed in water even when fracking wastewater made up only 0.01 to 0.1 percent of the waters’ volume. To prevent this from happening, the researchers recommended that fracking wastewater should not be discharged into surface waters, even when it is treated.

So why are we talking about water? I thought fracking was for oil and gas?


CREDIT: Environment America

Fracking is a technique that makes it easier for companies to get more oil and gas from the ground, but one of the reasons it’s so controversial is because of how much water is needed for that to happen. Fracking works better than conventional drilling because, instead of just drilling down and trying to extract gas from shale rock, companies also inject a high-pressure mixture of water, sand, and chemicals miles-deep into that rock. That high-pressure brine effectively cracks, or “fractures,” the rock, and makes the gas easier to extract.

As fracking has boomed across the United States, so has the use of water to do it. A 2013 report from Environment America showed that fracking wells nationwide produced an estimated 280 billion gallons of wastewater in 2012 — a huge number considering more than 55 percent of fracked wells are in areas experiencing droughts.

How to manage that water, which is often radioactive, has also been a huge issue. Some consider it an even bigger issue than fracking’s potential to leak drilling fluids or other contaminants, as detailed by a Yale Environment report on the problem.

What are some other problems with fracking wastewater?

Some of the most contentious issues surrounding fracking have been about wastewater. Drinking water contamination has always been one of them.

In addition to this most recent research on threats to drinking water supply from wastewater that’s been treated and released into rivers, some have been concerned about whether wastewater injected underground can contaminate aquifers. Environment America’s 2013 report said that pressure from those water injection wells can cause underground rock layers to crack, “accelerating the migration of wastewater into drinking water aquifers.”

Storage ponds of wastewater are also prone to accident. In 2013, federal regulators fined ExxonMobil $100,000 for a fracking wastewater pond leak in 2010 that contaminated a tributary of the Susquehanna River.

Perhaps the most high-profile concern with fracking wastewater, though, is that the process of injecting it underground may be causing earthquakes. Scientists increasingly believe that the large amount of water that is injected into the ground after a well is fracked can change the state of stress on existing fault lines to the point of failure, causing quakes. The quakes have usually been too small to be felt, but scientists have also warned that they stand to get stronger as more wastewater injection happens — a likelihood considering the growing expansion of fracking.