by Emil Morhardt
Colorado’s north Front Range, north of Denver and east of Boulder and Fort Collins has become a frackers’ paradise, with 24,000 active wells in 2012, 10,000 of them drilled since 2005. In the hot muggy summers, volatile organic compounds, including methane, ethane, propane, butane, pentane, and sometimes the carcinogen, benzene (all commonly found in oil and natural gas, O&G) accumulate in the air, leading to elevated ozone levels, and contributing to global warming. Previous estimates of the total amounts released were based on a combination of bottom-up estimates of releases from various sources based on a variety of sampling methods, as well as air samples from tower sampling stations. Extrapolating these to the whole O&G area carries all of the uncertainty associated with each of these estimates. In order to get a top-down, fully integrated estimate, Pétron et al., research scientists at NOAA, sampled the area from an airplane equipped with an instrument that continuously recorded methane, carbon dioxide, and carbon monoxide concentrations, and was also capable of taking discreet air samples for measuring other volatile organic compounds typically released from O&G operations. They found that the concentrations of most volatile organic compounds were twice as high, and that of benzene was seven times as high as previously estimated by the state of Colorado, and the hourly emissions rate was three times as high as estimated by the USEPA. The bottom line is that a lot more methane and other volatile organic carbons being released from the O&G operations than was previously thought.