Link Between Hydrofracking and Earthquakes Identified in Study

Processes that inject massive amounts of liquid into the ground, such as hydraulic fracturing and wastewater disposal wells, could contribute to earthquakes that may take lives and cause “widespread” damage, according to the findings of a new report.  

The journal Science published a report on July 12 by William Ellsworth of the Earthquake Science Center, part of the U.S. Geological Survey, which found a significant increase in potentially dangerous earthquakes in the mid-continental United States since 2001.

Ellsworth found that a number of these quakes, above a magnitude of 3.0, could be linked to underground fluid injection projects.

For years, the rate of earthquakes across the region was steady at about 21 events per year, according to Ellsworth. However, that number began to rise in 2001, peaking at 188 events per year in 2011. Those rates can be partially attributed to processes linked to oil and gas recovery operations like hydraulic fracturing and the disposal of wastewater from those operations into injection wells, Ellsworth determined.

While there has long been data that hydraulic fracturing and wastewater injection wells can cause smaller microearthquakes, Ellsworth found that they can also cause large, dangerous quakes as well. According to his report, a magnitude 5.6 earth quake in central Oklahoma may have been caused by a wastewater disposal injection project. It destroyed 14 homes and injured two people.

By comparison, the earthquake that shook Washington, D.C. and the surrounding area, damaging the Washington Monument, was a 5.8 magnitude quake with an epicenter in Louisa County in Virginia. It was felt by more people than any earthquake in U.S. history because of its location on the eastern seaboard.

There has been a rise in hydraulic fracturing operations in Maryland, Pennsylvania and New York over the past decade, which are far closer to massive population centers than the epicenter of the 2011 quake.

Ellsworth found that the wastewater injection wells were linked to more quakes than hydraulic fracturing, but such disposal operations are frequently linked to hydrofracking operations.

Hydraulic fracturing is a controversial process of gas extraction where a mixture of water, sand and fluids that the gas industry has fought to keep secret is injected into the ground at extremely high pressure, cracking shale deposits and freeing trapped natural gas, which can then be removed. Those fluids are then sucked from the ground and often disposed of in wastewater wells.

The earthquakes may be caused by the intense fluid pressure being injected into the ground, which can spark seismic activity.

Hydrofracking Concerns

Hydraulic fracturing, which is more commonly known as “fracking”, has come under increasing scrutiny over the last several years. It has become a popular method of gas extraction due to new drilling techniques and the discovery of large shale reserves throughout the eastern seaboard. It first began to boom in Wyoming and Montana’s Powder River Basin region, but now it has spread across the east coast in thousands of well sites in New York, Pennsylvania and Maryland.

There are a number of environmental concerns surrounding the fracking process. Residents near hydraulic fracturing sites have reported air pollution, dust problems, and claim that the fracking fluids contain pollutants that contaminate groundwater.

Last year the Occupational Safety & Health Administration (OSHA) and the National Institute for Occupational Safety and Health (NIOSH) issued a joint hazard alert that silica dust from the operations put workers at risk.

A study published last month by the National Academy of Sciences linked hydraulic fracturing operations to methane, ethane and propane contamination of drinking water.

Efforts to force the industry to reveal what is in the fluids have so far been blocked. A number of states have enacted controls or moratoriums to slow down the spread of the process until its environmental effects have been better understood.