Injecting old, used water from oil and gas drilling in California has been tied to earthquakes for the first time, according to a new study released Thursday. Wastewater injections have already been tied to earthquakes in Colorado and Oklahoma.
The study comes as fracking in California is growing in scope — and in attention. During fracking, chemical-laced, saline water is injected at high pressure thousands of meters underground, loosening deposits of oil and gas. The process, as well as other forms of so-called enhanced oil recovery, creates huge amounts of wastewater, which is often disposed of by being injected into storage wells. (It is also occasionally reused in agriculture or dumped in the ocean.)
California’s wastewater injections have already raised concerns and prompted lawsuits, after environmentalists discovered oil and gas companies have received permits from the Dept. of Conservation to inject into protected aquifers.
According to the new study, which tied a set of 2005 earthquakes near Bakersfield, Calif., to wastewater disposal, injection wells can potentially cause earthquakes several kilometers away, both in the short term and months or even years after the injections take place. The earthquakes studied in the recent report occurred roughly five miles from the injection sites. Bakersfield, in Kern County, is roughly 50 miles from the San Andreas Fault.
While this might be the first conclusive study on injection-induced earthquakes in California, the issue has been on people’s minds. In 2014, the Center for Biological Diversity issued a report titled “On Shaky Ground: Fracking, Acidizing, and Increased Earthquake Risk in California.” And then last year, the Dept. of Conservation commissioned the California-based Lawrence Berkeley National Laboratory to do a “comprehensive study on the potential for induced seismicity related to injection for disposal of produced water in California oilfields,” Don Drysdale, a spokesperson for the state agency, told ThinkProgress via email. The results of this study will aid in permitting and regulating future wastewater injection operations in the state. The department has also announced that it is revising its program for regulating underground injections. A discussion draft for those revisions was released earlier this year.
As of last July, operators are required to monitor seismic activities during extraction, Drysdale said. However, companies are not required to do that same monitoring during wastewater disposal.
“Wastewater disposal is a routine activity,” Drysdale said.
But data from the Dept. of Conservation shows that annual wastewater injections across the state have doubled since 1995. Meanwhile, oil production has fallen by a quarter (as of 2014, the last year for which there is data). Gross natural gas production has fallen by a third. This is likely due primarily to the increase fracking and enhanced oil recovery, techniques that use much more water than traditional drilling.
According to Shaye Wolf, a researcher with the Center for Biological Diversity and co-author of the group’s report, it’s wastewater injection wells that are most concerning.
“State regulators haven’t been looking at the risk of inducing earthquakes from the massive amounts of oil and gas wastewater that is being injected in California,” Wolf said. “Those are the ones in particular that have been linked to the swarms of earthquakes that have been caused in the Midwest.”
The new causation study, published in Geophysical Research Letters, points out that there is actually more wastewater injected in California than in Oklahoma, where a number of studies have found a link to earthquakes.
In fact, the situation in Oklahoma has gotten so bad that the Oklahoma Corporation Commission, which oversees oil and gas extraction, has asked companies to stop injecting wastewater in some areas. One company recently became the first to refuse to comply with the request. The commission intends to take the company to court to rescind its permits.
The tension between residents and the oil and gas industry there has gotten intense. There is at least one lawsuit in the state, alleging that an oil company is responsible for an injury that occurred during an earthquake.
Gov. Mary Fallin recently approved $1 million in additional state funds to researching earthquakes and supporting the commission’s oil and gas regulations.
U.S. Geological Survey researchers have also connected earthquakes to wastewater injection in Colorado and New Mexico.
One of the problems researchers in California have had is that there is already a lot of seismic activity in California — and there has been oil and gas extraction for a century. And oil and gas companies are only required to report monthly average data — while seismic experts say that the pressure and speed of injections are most correlated with induced earthquakes.
“We have every reason to believe that this is the tip of the iceberg in terms of wastewater-induced earthquakes in California,” Wolf said.