Nonetheless, people’s concern that fracking can taint our drinking water with unsavory and possibly dangerous elements is not unfounded.Ī study published in May 2011 in the peer-reviewed Proceedings of the National Academy of Sciences found a link between methane in drinking water supplies and proximity to shale gas drilling. Maybe you’ve seen this startling scene from the Oscar-nominated film GasLand:Īs it turns out, the faucet here was spewing naturally occurring methane, which is difficult to attribute to fracking in a direct, conclusive way. Do those chemicals get into drinking water? Others, like sodium chloride (table salt) and guar gum (a common food thickener derived from beans) are generally benign.ģ. Exposure to high amounts of some common frack-fluid chemicals, like ethylene glycol (a key antifreeze ingredient), have been linked to serious health problems, such as kidney, heart, and nervous-system damage. Chemicals: A chemical cocktail of “additives,” in industry speak, helps to dissolve minerals, reduce friction, prevent corrosion, thicken the fluid (so it can transport the sand), clean out debris, prevent clay from swelling, and fight bacteria, among other jobs.Īt various stages, the list of chemical ingredients may include hydrochloric acid, petroleum distillates, ammonium persulfate, calcium chloride, boric acid, citric acid, borate salts, and many more additives.In place of sand, some drillers use ceramic pellets or other particles. Sand: Grains of sand, acting as “proppants,” keep cracks in the shale open so gas can flow out of the rock and up the well.Energy companies often buy water from farmers, lease surplus water from municipalities, or buy treated wastewater. Water: An Olympic-size swimming pool holds about 660,000 gallons of water, and a single fracking well can use seven or eight times that amount.There are three basic ingredients in fracking fluids: And none too soon, since we’ve already harvested much of the low-hanging fruit (read: the big, easily tapped gas deposits). Horizontal drilling, combined with fracking, makes it worthwhile for companies to tap gas stores that just wouldn’t have been economical a few years back. The wells’ L shape, enabled by advances in “horizontal drilling” over the last decade, makes it possible to tap many small pockets of gas scattered across wide, thin rock layers. Gas flows out of the rock and up to the surface. The pressurized fluid creates tiny cracks, or fissures, in the shale around a borehole far below ground level. Frackers pump up to 4 million gallons of fluid as far as 10,000 feet below ground at up to 4,200 gallons per minute. It takes more than a garden hose to get this job done. Drillers also use fracking to release gas from fine-grained sands known as tight sands, and to free methane from coal beds. Often this rock is a very tight, clay-rich, sedimentary mud stone known as shale - for example, the Marcellus Shale formation in New York, Pennsylvania, West Virginia, Ohio, and Maryland the Bakken Shale in North Dakota and the Barnett Shale in Texas. Here's Howĭone right, fracking can squeeze natural gas from layers of rock that would otherwise be too difficult or costly to exploit. To support our nonprofit environmental journalism, please consider disabling your ad-blocker to allow ads on Grist. They are still working to understand the long-term implications of using this technology at large scale in the real world, however, where things spill, accidents happen, and people have their health, homes, schools, airports, groundwater, and even cemeteries to worry about. Scientists assure us that fracking can be done safely - at least in theory. natural gas production, up from virtually nil a few years ago. And shale gas (often fracked) now accounts for 15 percent of total U.S. As many as 35,000 wells are fracked each year, according to the Environmental Protection Agency (EPA). By turns demonized as a catastrophic environmental threat and glorified as a therapy for our foreign oil addiction, fracking has become a flashpoint in our national energy policy.įirst developed in the 1940s, fracking - literally, “hydraulic fracturing,” or “smashing rock open with lots of water” - only began to boom around 2005, but today, it’s used in nine out of every 10 natural gas wells in the U.S. “Fracking”: It sounds more like a comic-book exclamation ( kapow! boom! frack!) than a controversial method for extracting natural gas and oil from rock deep underground.
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