Hydraulic fracturing techniques have resulted in thousands of spills in four states over a 10-year period, a new study finds.
Researchers at Duke University say they have identified at least 6,648 fracking-related spills in Colorado, Pennsylvania, New Mexico, and North Dakota between 2005 and 2014. North Dakota was home to at least 4,453 incidents, or 67 percent of the spills that were recorded, followed by Pennsylvania at 1,293, Colorado reported 476 spills, while New Mexico reported 426.
The study is a stark contrast to an earlier survey carried out by the Environmental Protection Agency (EPA), which studied spills in eight states between 2006 and 2012 and concluded that 457 spills had occurred.
Researchers noted the EPA study limited itself to spills caused directly by the hydraulic fracturing process, which lasts only a few days or weeks. The Duke University study, by comparison, reviewed data from wells from the time of drilling through production, which can last decades. The researchers also analyzed how variations in state-level spill reporting criteria can contribute to uncertainty among industry leaders and policymakers as to the true extend of the problem. The findings were published in the scientific journal Environmental Science & Technology.
State spill data holds great promise for risk identification and mitigation,” lead author Lauren Patterson said. “However, reporting requirements differ across states, requiring considerable effort to make the data usable for analysis.”
The rate of spills differed wildly according to each state, which is due to the varying minimum thresholds for reporting spill incidents. North Dakota, which has seen a tsunami of oil and gas drilling activity over the last decade, requires companies to report spills of 42 gallons or more. Colorado and New Mexico, by contrast, only require reports for spills of at least 210 gallons.
Most of the spills occurred in the first three years of operation. At least half were related to the storage and transport of oil via pipelines.
“The causes are quite varied,” said Dr. Patterson. “Equipment failure was the greatest factor, the loading and unloading of trucks with material had a lot more human error than other places.”
A large number of spills were reported at sites which had recorded a previous incident, including over half of the spills in North Dakota. Study authors suggest that targeted inspections of wells with a history of recorded spills can mitigate repeat incidents.
Industry advocates, who did not dispute the study’s findings, nonetheless downplayed the impact these spills are having, arguing that very few of the spills have resulted in contamination of the environment.
“The reality is that North Dakota requires that companies report any spills that are a barrel or more, even if they never impact the environment – and the vast majority of spills have not,” said Katie Brown from Energy in Depth, a research organization funded by petroleum producing companies.
“According to the North Dakota Department of Health, 70% of all spills in 2013 were contained on the well pad and never reached land or water,” she said.