Hydrofracking sparks earthquake concerns

Source:ithacajournal.com

ROCHESTER -- In early 2001, people living in northern Steuben County experienced something that many of them had never felt before -- a series of earthquakes, the largest of which was more powerful than any naturally occurring tremor in New York in a decade.

Damage was minimal but nerves were jangled. Because the epicenters were in an area not known to be quake-prone, officials looked for an explanation. They found one that might seem improbable.

The earthquakes were man-made, New York officials suspected -- the result of test injections of millions of gallons of water into two-mile-deep disposal wells built as part of a natural-gas storage operation being developed in the Town of Avoca.

State officials ordered a halt to the well tests. The elaborate gas storage facility was never finished and the site eventually abandoned.

The incident, which largely went unnoticed outside of Avoca and neighboring Cohocton, has been given fresh currency today because of the growing controversy in New York and nationwide over the natural gas drilling technique known as hydraulic fracturing.

The surge in hydrofracking has meant a surge in injection wells to dispose of drilling wastewater -- and those disposal wells are increasingly being linked to small earthquakes. Clusters of "induced" quakes in the Dallas-Forth Worth area and in Arkansas are prominent recent cases.

"There's a long list of examples," said Robert Ross, a geologist and associate director for the Paleontological Research Institution in Ithaca. "There's no question that small earthquakes can be induced."

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Oklahoma earthquakes raise more questions about hydrofracking, injection wells

By David O. Williams
Monday, November 07, 2011
The Colorado Independent

A holding pond for fracking fluids in Texas.

Another swarm of earthquakes in an unusual part of the country has generated aftershocks of debate about whether the oil and gas drilling process called hydraulic fracturing, or fracking, is to blame.

The early returns in Oklahoma, where a 5.6-magnitude earthquake near Sparks damaged buildings and rattled nerves on Saturday, are inconclusive. Much as scientists said there just isn’t enough evidence to link earthquakes this summer in Virginia and Colorado to fracking, officials over the weekend declined to connect the Oklahoma quake to the common drilling practice.

The process of fracking involves the high-pressure injection of water, sand and chemicals into oil and gas wells to break up tight rock and sand and free up more hydrocarbons. The fracking fluids are then stored for later use, recycled or disposed of in injection wells.

According to the Associated Press, there are 181 such injection wells in the vicinity of Saturday’s Oklahoma quake and Sunday’s aftershocks. AP also reported Oklahoma typically only experienced about 50 earthquakes a year until 2009 when that number spiked dramatically. Last year there were 1,047 small quakes in the area, prompting the installation of seismographs.


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