Oil and Gas Mining Causing Frequent Quakes in Oklahoma, State, Federal Investigators Confirm

Federal and Oklahoma state investigators say they are now certain that wastewater injection wells and hydraulic fracturing operations are responsible for a rise in earthquakes in Oklahoma, following a number of studies into tremors in areas near controversial fracking sites. 

Oklahoma now experiences more earthquakes than California, thanks to wastewater injection wells and hydraulic fracturing operations, commonly known as fracking, according to U.S. Geological Survey (USGS) report issued on April 23.

“This new report describes for the first time how injection-induced earthquakes can be incorporated into U.S. seismic hazard maps,” Mark Petersen, Chief of the USGS National Seismic Hazard Modeling Project, said in a press release. “These earthquakes are occurring at a higher rate than ever before and pose a much greater risk to people living nearby. The USGS is developing methods that overcome the challenges in assessing seismic hazards in these regions in order to support decisions that help keep communities safe from ground shaking.”

The USGS said that fracking is responsible for some of the quakes, while disposal of wastewater from oil extraction operations into deep injection wells is responsible for most.

The state hardest hit by induced earthquakes appears to be Oklahoma. Investigators from the Oklahoma Geological Survey issued a statement (PDF) on April 21, acknowledging the high rate of induced earthquakes, which it also said was the result primarily of wastewater injection wells. However, a small percentage of the quakes are also caused by hydraulic fracturing.

According to Oklahoma investigators, the rate of earthquakes in 2013 was 70 times greater than rates prior to 2008. However, that rate is increasing geometrically. Currently, they say the rate of earthquakes is about 600 times greater than it was in 2008.

Historically, Oklahoma experienced one and a half earthquakes of magnitude 3.0 or greater every year. It now experiences two such earthquakes every week, according to state investigators.

Both state and federal investigators said that while hydraulic fracturing is certainly responsible for some of the quakes, it makes up only a small amount of the water injected into ground formations linked to the increased seismic activity.

Hydraulic Fracturing Earthquake Concerns

Hydraulic fracturing is a 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.

Researchers have seen a dramatic increase in the number of earthquakes in the central and eastern United States over the past few years. Those earthquakes have coincided with hydraulic fracturing and wastewater disposal wells, particularly in Arkansas, Colorado, Ohio, Oklahoma, and Texas, according to studies.

From 1967 to 2000, there were an average of 21 earthquakes per year above magnitude 3.0. From 2010 to 2012, as hydraulic fracturing took off, so did the number of earthquakes of magnitude 3.0 or higher, with an average of 100 per year, according to the USGS.

Fracking earthquakes can not only happen miles away from the wells, threatening human life, but they can also threaten vital structures such as dams and nuclear power plants, scientists warn.

A study published in the journal Science on February 20 first outlined the USGS findings,

That study came just a month after a similar report was published in the Bulletin of the Seismological Society of America, which reported that 77 earthquakes likely linked to fracking operations shook the area around Poland Township in Ohio in just a week’s time in March 2014.

Other Fracking Concerns

The controversial fracking process has come under increasing scrutiny over the last several years, as it has become a more popular method of gas extraction with the development of new drilling techniques and the discovery of large shale reserves.

Critics have linked fracking to a variety of pollutants, claiming it puts groundwater sources at risk and that increased truck traffic, air pollution and other problems can reduce property values and sicken nearby residents.

In December 2014, the state of New York banned hydraulic fracturing, after a study found questions and concerns regarding the safety of large-scale extraction wells.

State officials said that a six-year study’s findings indicate dozens of significant potential adverse impacts, and found that the risks of high-volume hydraulic fracturing outweigh any potential economic benefits.

Environmentalists, a number of lawmakers, local communities and consumer advocacy groups have expressed concerns for years that hydrofracking presents a threat to groundwater supplies and the environment.

In 2014, a Texas jury awarded $2.9 million in damages to a family who sued a hydraulic fracturing company for being a public nuisance. According to allegations raised in a fracking lawsuit filed by the Parr family, nearly two dozen wells near their property caused a private nuisance, exposing them to toxic chemicals that damaged their health and lowered property value.