Potential Radon Release during Fracking in Colorado

Hydraulic fracturing or 'fracking' has become the industry standard for oil and gas production in the United States. The process entails fracturing large sections of rock with high pressure to release oil and gas reserves and to produce conduits for these fluids to flow more easily to the surface. Along with the intended natural gas, water, or any other fluids or other substances that might be trapped with the gas in the tight formation shales and sandstones that are fracked, come to the surface. There is some evidence that radium-226, radon-222 and other toxic substances have been detected at well heads of fracking operations (McMahon, 2013 and Tait et al., 2013). The foothills and plains along the Front Range in Colorado have become an active area for gas and oil production. Most of this activity takes place in the upper Cretaceous limestone/shale Niobrara formation and the underlying Codell sandstone that generally lie between 2,000 and 3,000 meters below the surface. The fracked rock releases radon that was trapped by the tight shale formation which then is able to flow along the lateral sections of the fracked zone and be pumped up the well bore to the surface. Radon is then released to the atmosphere at the fracking site in levels which may be of some health concern to nearby workers or residents. Actual radon222 measurements made about 200 feet (60 m) from one well pad (with five well heads) prior to, during, and after fracking showed levels around 3 pCi/L, or 111 Bq/m. A second test series at several well three-phase separation/storage facilities and a recently completed well pad, also in northeast Colorado, indicated outdoor radon levels around 4.5 pCi/L, or 166.5 Bq/m. We believe additional monitoring needs to be done to better characterize the radon levels released during the fracking process and at the many separation/storage facilities in the rather large geographical area.