Jake Slobe | March 1, 2017
Each year, 2 to 16 percent of hydraulically fractured oil and gas wells spill hydrocarbons, chemical-laden water, hydraulic fracturing fluids and other substances, according to a new study.
The analysis, published Environmental Science & Technology, identified 6,648 spills reported across Colorado, New Mexico, North Dakota and Pennsylvania over a 10-year period.
Researchers examined state-level spill data to characterize spills associated with unconventional oil and gas development at 31,481 wells hydraulically fractured or fracked in the four states between 2005 and 2014.
Lauren Patterson, policy associate at Duke University’s Nicholas Institute for Environmental Policy Solutions and the study’s lead author.
“State spill data holds great promise for risk identification and mitigation. However, reporting requirements differ across states, requiring considerable effort to make the data usable for analysis.”
North Dakota reported the highest spill rate, with 4,453 incidents, followed by Pennsylvania at 1,293, Colorado at 476 and New Mexico at 426. The number of spills reported is partly a reflection of the reporting requirements set by each state. For example, North Dakota required reporting smaller spills (42 gallons or more) than Colorado and New Mexico (210 gallons or more).
The results of the study exceed the 457 spills calculated by the U.S. Environmental Protection Agency (EPA) for eight states between 2006 and 2012 because the EPA’s analysis only considered the hydraulic fracturing stage, rather than the full life cycle of unconventional oil and gas production.
Fifty percent of spills identified in the Environmental Science & Technology article were related to storage and moving fluids via pipelines, although it was not always possible to determine the cause of the spill because some states explicitly required this data to be reported while others relied on narrative descriptions.
Across all states, the first three years of a well’s life, when drilling and hydraulic fracturing occurred and production volumes were highest, had the greatest risk of a spill. The study found that a significant portion of spills (from 26 percent in Colorado to 53 percent in North Dakota) occur at wells that experienced more than one spill, which suggests that wells where spills have already occurred merit closer attention.