One Researcher’s Quest To Quantify The Environmental Cost Of Abandoned Oil Wells
Amy Townsend-Small has been chasing methane her entire professional life. The quest has taken her from Southern California freeways to sewage plants to animal feedlots. Sniffing out the potent greenhouse gas, which traps 86 times as much heat as carbon dioxide after it’s emitted into the atmosphere, has required her to breathalyze cows and take chemical measurements at large manure lagoons. When fracking took off around 2010, Townsend-Small shifted her focus to a new and growing problem: methane leaks from oil and gas activity.
Townsend-Small began trying to quantify just how much methane was leaking from wells and pipelines. She investigated whether methane from fracking sites may have tainted groundwater in rural Ohio and collected data on pipeline and compressor station leaks in Colorado. The work of Townsend-Small and other environmental scientists tracking greenhouse gases culminated in a 2018 study finding that 2.3 percent of the natural gas extracted in the country either leaked or was directly released into the air—the equivalent of the carbon dioxide emitted by all coal plants operating at the time.
In 2016, Townsend-Small found that 40 percent of unplugged wells she tested in Colorado, Wyoming, Ohio, and Utah were emitting methane. On average, each unplugged well was leaking about 10 grams of methane each hour, contributing the annual carbon equivalent of burning more than 2,400 pounds of coal. The EPA used her research to estimate that the nation’s approximately 3.1 million abandoned wells were spewing greenhouse gas emissions equivalent to burning more than 16 million barrels of oil.
Of the 17 wells where methane leaks were detected, the emission rates ranged from 0.2 to 132 grams an hour. Just three wells at the high end of that range were responsible for 94 percent of all emissions. The phenomenon—in which a handful of especially leaky wells that Townsend-Small and other researchers call “super emitters” are responsible for the vast majority of emissions—is a pattern that’s also been observed in the Appalachian Basin and other oil fields in the country.