Thousands of leaks at fracking locations

Discharge of potentially environmentally harmful substances, especially on tanks and pipelines

Fracking plant in Pennsylvania. The beige colored tubes in the middle pump fracking fluid into the rock © Doug Duncan / USGS
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More than thought: In the past decade, fracking sites in the US have released more oil, fracking fluids, and other chemicals into the environment than previously thought. More than 6, 600 leakages were reported in four US states alone, according to an evaluation. Most of the leaks occurred at the storage tanks and pipelines of such facilities - and usually in the first three years of operation.

Gas extraction by fracking is highly controversial. - partly because of the environmental consequences observed in the USA. Thus, air measurements at fracking sites show greatly increased levels of toxic vapors and there are indications of increased premature births in the vicinity of the plants. It is also known that the fracking liquid contains toxic chemicals. Some time ago, researchers also warned against contamination of drinking water by leaks in the plants.

Lauren Patterson of Duke University and her colleagues have now determined how many leaks and leaks of oil, fracking fluids and other chemicals actually occur at fracking locations. For their study, they evaluated all the reported departures of the 30, 000 fracking sites in the four states of Colorado, North Dakota, Pennsylvania, and New Mexico over the last decade.

Thousands of leaks

The result: More than 6, 600 leakages and leaks of varying sizes were reported in these four states alone. Between two and 16 percent of the fracking plants have reportedly released at least once potentially environmentally harmful liquids in the environment, as the researchers report.

And this number of withdrawals could even be greatly underestimated: The regulations, from which size a leak must be reported, are different in the federal states, explain the scientists. In North Carolina, for example, 42 gallons released into the environment are notifiable, while in New Mexico only more than 120 gallons of liquid are released. Smaller leaks therefore fall in some states simply through the grid. display

Storage tanks for polluted water, which was pumped up again from the underground. At such tanks, many of the leaks occurred. Doug Duncan / USGS

Much higher than previously calculated

But even if you ignore this fact, the number of fracking leakages is significantly higher than previously calculated by the US Environmental Protection Agency EPA. This was only 457 leaks in six years, the scientists said. The reason for this is that the EPA takes into account only the leaks in the fraying itself, but not the entire process of unconventional oil and gas production.

"However, it is important to know leaks at all stages of the fracking promotion, as this includes the transport of materials to and from the sites, as well as the storage of the materials on site, " explains Patterson. "Only by examining all stadiums can one understand the risk of such withdrawals."

Storage tank and pipeline

In fact, the evaluations showed that most leaks were not caused by the gas and oil transportation itself, but by leaky storage tanks or leaks in pipes. It was not always the fault of the material or the equipment: at least 700 cases were human failures. However, with around 4, 000 other cases, the exact cause is still unclear.

Amounts of the leaked substances in the reported leaks. Science for Nature and People Partnership

Among the released substances were, in addition to water, especially fracking fluid, Erd l and a mixture of oil and salt water, as the evaluation showed. However, various chemicals as well as diesel and oil, which were needed to operate the pumps and machines, frequently leaked in the leakages. In many cases contamination of waters or groundwater occurred.

First three years are the most dangerous

In analyzing the temporal and spatial distribution of leaks, the scientists identified two clear trends: First, the risk of leakage or major leakage in the first three years of operation of a fracking facility the highest. This is due to the fact that during this time not only the plants are being built, but also that during this time the quantities are the largest, as the researchers explain.

On the other hand, it turned out that accidents and leaks were rising at certain locations. It may therefore be worth postponing locations after a reported exit to find systematic errors or defects, say Patterson and her colleagues.

"Analyzes such as these are important in order to better assess and combat the risk to water resources and human health, " says Kate Konschnik of Harvard Law School. In addition, this information helps to improve the reporting obligations in future and to standardize. (Environmental Science & Technology :, 2017; doi: 10.1021 / acs.est.05749)

(Duke University, 22.02.2017 - NPO)