Like all known sources of commercial-scale energy, hydrofracking is not environmentally benign.
Hydrofracking in Wyoming, in particular, has led to smog that was worse than levels recorded in Los Angeles. According to the EPA, ground level ozone, the primary component of smog, can cause permanent lung damage with repeated exposure.
Natural gas, which is primarily composed of methane, is among the more potent greenhouse gases. According to the EPA, methane has 21 times the greenhouse gas potential of carbon dioxide over a 100-year period.
Using a 21 - 1 ratio, 21 tons of carbon dioxide is equivalent to one ton of methane. The EPA estimates that about 475 billion standard cubic feet of methane is vented annually by the completion of unconventional gas wells.
Perhaps the process’ most infamous environmental impact is water contamination. Allegations of hydrofracking polluting water wells with toxic chemicals have spread all the way from Wyoming to Pennsylvania and some states between.
This December the EPA released findings that hydrofracking contaminated water in Pavilion, Wyo. In Dimock, Pa., some residents are suing Cabot Oil & Gas alleging that natural gas drilling contaminated their well water with toxic chemicals, caused sickness and reduced their property values.
According to Selleck, who specializes in hydrogeology, if the fluids pumped into wells are contained properly there is little risk of water contamination. However, surface spills and faulty well casings hold significant potential to contaminate water.
“The [water problems from hydrofracking] are really related to the near surface activities and the stability of the drill hole and the casings,” Selleck said. At the surface of a hydrofracking site there are “huge amounts of material being moved around and lots of flow-back water, there’s certainly potential for spilling or surface drainage impacts.”
Treating waste fluid, or flow-back water, from hydrofracking is another means of potential water contamination.