Methane Leaks Pose Public Health, Safety Risk at Alberta’s Abandoned Wells
Hundreds of abandoned oil and gas wells in Alberta are leaking methane at rates high enough to pose local health and even explosion risks, Andrew Nikiforuk asserts in The Tyee, citing a previously unreleased study by the Alberta Energy Regulator.
“Based on the testing of just 338 wells,” Nikiforuk writes, “the study estimated that 17,000 out of 170,000 abandoned wells in rural Alberta are leaking methane, and that leaks at 3,400 wells could pose a risk to the public.” In addition to being toxic to people and flammable in sufficient concentration, methane is a greenhouse gas many times more potent than carbon dioxide on a short time horizon.
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The Alberta regulator’s study closely examined 335 wells close to houses, airports, businesses, and other surface development. It “found that 36 were leaking methane,” Nikiforuk says. “Nine of those were leaking at a level that Alberta Health says poses a risk of neurological damage to nearby residents. Six wells that exceeded the emergency evacuation threshold of 10,000 ppm were outside buildings. Three other hazardous wells had ‘methane leakage inside buildings.’”
The AER deemed an additional 53 abandoned wells hazardous because of their questionable containment of sour gas (gas naturally laced with hydrogen sulphide, a powerful neurotoxin) or high acid levels. The study did not test for other well-known public health hazards associated with poorly-capped oil and gas wells like benzene, toluene, xylene, and hydrogen sulfide. Some 1,100 abandoned wells in major centres like Edmonton, Lethbridge, and Calgary “still need to be located and tested for leakage,” according to the Alberta regulator.
“The methane toxicity study, never released to the public, was completed in November 2016,” Nikiforuk writes. “When The Tyee asked for a copy two months ago, ministry press secretary Laura Ehrkamp said officials couldn’t find it.”
The disclosure of its contents now caps a series of revelations documenting how Alberta’s citizens find themselves on the hook for billions of dollars in clean-up costs at a growing number of oil and gas facilities abandoned by their previous owners.