Viewers of Gasland, a new documentary about the alleged sins of the natural gas industry, are treated to some impressive pyrotechnics when a homeowner lights his tap water on fire. The man claims his drinking water has been contaminated by a nearby natural gas well that was drilled using the hydraulic fracturing technique, also known as fracking. Fracking received further critical media scrutiny in November when the CBS investigative program 60 Minutes featured a segment on the Pennsylvania town of Dimock where residents assert their groundwater has been polluted by fracked natural gas wells. As the tide of protests against fracking rose, New York Gov. David Paterson (D) earlier this month ordered a seven month moratorium on new fracked natural gas wells.
Fracking is a process in which a mixture of water, sand, and other additives are pumped under high pressure to create fractures in rock formations to release trapped oil and gas. About 100,000 wells using fracking technology are drilled worldwide each year. In the case of natural gas, fractures are propped open by the sand, allowing trapped gas to flow into the wellbore and rise to the surface for collection. The technique gives drillers access to gas trapped in vast deep shale formations such as the Marcellus Shale which stretches more than 5,000 feet underground through New York, Pennsylvania, Ohio, and West Virginia. Until new horizontal drilling techniques combined with fracking were developed, extracting gas from shale was uneconomical.
The main environmental concern is that fracking contaminates groundwater. But is that so? In September, the environmental activist group Riverkeeper issued a report, Fractured Communities [PDF], in which the group claimed to have assembled "hundreds of case studies demonstrating that industrial gas drilling, including horizontal drilling using high-volume hydraulic fracturing, results in significant adverse environmental impacts." The report is right that natural gas drilling can harm the environment, but the crucial question is does fracking, per se, endanger the environment, especially groundwater.
Most of the fracking fluids stay well underground once injected, but some flow back out as "produced water." This water contains some of the chemicals used to make fracking fluids as well as various dissolved salts picked up from the shale itself. In fact, spills of this produced water have contaminated ground and surface water. Currently, most of the produced water is trucked to treatment plants which remove these contaminants from the water before it is discharged into waterways.
One oft-voiced complaint is that drilling companies are suspiciously cagey about just what chemicals are contained in their proprietary fracking fluids. In general, fracking fluids are 99.5 percent water and sand. Some chemicals are added to prevent corrosion, reduce friction, and kill fouling bacteria. Earlier this year, the U.S. Environmental Protection Agency launched a new study to investigate the possible relationships between hydraulic fracturing and drinking water. All nine of the leading drilling companies have agreed to tell the agency the chemical recipes of their fracking fluids. The agency expects the study to be completed by 2012.
In the meantime several states, including Wyoming, Arkansas, and New York, are requiring that drilling companies release information on the makeup of their fracking fluids. In November, Halliburton, one of the bigger drilling companies, announced its new CleanStim product, a fracking fluid formulated using ingredients sourced from the food industry.
Not surprisingly, the natural gas industry asserts that fracking is safe—and that it is vital to unlocking vast new domestic supplies of natural gas from shale formations. A 2008 report by the Groundwater Protection Council, a nonprofit organization whose members consist of state groundwater regulatory agencies, found that the layers of impermeable rock over top of the Marcellus Shale act as a barrier so that the water and chemicals used in fracking could not migrate upward into groundwater aquifers. In addition, a September 2010 report by the Pennsylvania Department of Environmental Protection reviewed its complaint database and concluded "that no groundwater pollution [PDF] or disruption of underground sources of drinking water have been attributed to hydraulic fracturing of deep gas formations."
So if fracking is not the cause of flaming tap water and groundwater pollution in Dimock and elsewhere, what is?
Since 2006, Cabot Oil and Gas has drilled nearly 60 wells in a nine square mile area around Dimock, using the fracking technique. In January, 2009 several homeowners noticed that water from their wells was now bubbling. The Pennsylvania Department of Environmental Protection investigated and concluded that natural gas was in fact migrating from several Cabot gas wells into local groundwater and into homeowners' wells. But poor well construction was to blame. A properly cased well prevents drilling fluids, fracking fluids, or natural gas from seeping into an aquifer and contaminating groundwater. The casing also prevents groundwater from leaking into the well where it could interfere with the gas production process.
In Dimock, gas was escaping through defective casings and cement that lined some of Cabot's gas wells. To make matters worse, in September 2010, Cabot spilled 8,000 gallons of stored fracking fluids which drained into nearby Stevens Creek. Earlier this month, Cabot agreed to pay affected homeowners more than $4 million which amounts to twice the value of their houses. Cabot's blunders illustrate an important point: Fracking, that is, the actual act of fracturing the shale below Dimock, did not directly pollute ground and surface waters. Of course, without fracking technology, there would have been no gas wells in the Dimock area.
Just how big are the stakes in the fight over fracking? In its Annual Energy Outlook 2011 [PDF] report, the Energy Information Administration estimates that the United States possesses 2,552 trillion cubic feet (Tcf) of potential natural gas resources, of which for 827 Tcf resides in shale formations. Shale gas reserves are more than double the estimate published last year. The EIA notes that at the 2009 rate of U.S. consumption (about 22.8 Tcf per year), 2,552 Tcf of natural gas is enough to supply approximately 110 years of use. The EIA further notes that shale gas supplied 14 percent of the gas used in the U.S. in 2009 and projects that it will constitute 45 percent of U.S. total natural gas supply in 2035. In addition, burning natural gas produces half the greenhouse gases that coal does and the EIA projects that supplies will be so abundant that the price should remain low for the next 20 years. That's if fracking is not banned.
Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books.
Disclosure: I receive royalties totaling about $1,000 per year from conventional natural gas wells in West Virginia.