. . . A series of government and academic
studies over the past few years — including at least two reports released this
week alone — has added to the body of evidence implicating the U.S. drilling
boom that has created a bounty of jobs and tax revenue over the past decade or
so.
On Thursday, the U.S. Geological
Survey released the first comprehensive maps pinpointing more than a dozen
areas in the central and eastern U.S. that have been jolted by quakes that the
researchers said were triggered by drilling. The report said man-made quakes
tied to industry operations have been on the rise.
Scientists have mainly attributed
the spike to the injection of wastewater deep underground, a practice they say
can activate dormant faults. Only a few cases of shaking have been blamed on
fracking, in which large volumes of water, sand and chemicals are pumped into
rock formations to crack them open and free oil or gas.
"The picture is very
clear" that wastewater injection can cause faults to move, said USGS
geophysicist William Ellsworth.
Until recently, Oklahoma — one of
the biggest energy-producing states — had been cautious about linking the spate
of quakes to drilling. But the Oklahoma Geological Survey acknowledged earlier
this week that it is "very likely" that recent seismic activity was
caused by the injection of wastewater into disposal wells.
Earthquake activity in Oklahoma in
2013 was 70 times greater than it was before 2008, state geologists reported.
Oklahoma historically recorded an average of 1.5 quakes of magnitude 3 or greater
each year. It is now seeing an average of 2.5 such quakes each day, according
to geologists.
Angela Spotts, who lives outside
Stillwater, Oklahoma, in an area with a number of wastewater disposal wells,
said the shaking has damaged her brick home. She pointed to the cracked
interior and exterior walls, and windows and kitchen cabinets that are
separating from the structure.
"There's been no doubt in my
mind what's causing them," Spotts said. "Sadly, it's really taken a
long time for people to come around. Our lives are being placed at risk. Our
homes are being broken."
Yet another study, this one
published Tuesday in the journal Nature Communications, connected a swarm of
small quakes west of Fort Worth, Texas, to nearby natural gas wells and
wastewater disposal.
The American Petroleum Institute
said the industry is working with scientists and regulators "to better
understand the issue and work toward collaborative solutions."
The Environmental Protection Agency
said there no plans for new regulations as a result of the USGS study.
"We knew there would be
challenges there, but they can be overcome," EPA Administrator Gina
McCarthy said Thursday at an energy conference in Houston.
For decades, earthquakes were an
afterthought in the central and eastern U.S., which worried more about
tornadoes, floods and hurricanes. Since 2009, quakes have sharply increased,
and in some surprising places.
The ground has been trembling in
regions that were once seismically stable, including parts of Alabama,
Arkansas, Colorado, Kansas, New Mexico, Ohio, Oklahoma and Texas.
The largest jolt linked to
wastewater injection — a magnitude-5.6 that hit Prague, Oklahoma, in 2011 —
damaged 200 buildings and shook a college football stadium.
The uptick in Oklahoma quakes has prompted
state regulators to require a seismic review of all proposed disposal wells.
The Oklahoma Corporation Commission, which regulates the oil and gas industry,
has ordered dozens of disposal wells to stop operating or change the way they
are run because of concerns they might be triggering earthquakes, said
spokesman Matt Skinner.
"There are far more steps that
will be taken," Skinner said.
Last year, regulators in Colorado
ordered an operator to temporarily stop injecting wastewater after the job was
believed to be linked to several small quakes.
* * *
Alicia Chang, Scientists Convinced of Tie Between Earthquakes and Drilling, AP, April 23, 2015. For a scientific study with neat graphics (h/t/Desdemona), see Causal Factors for Seismicity near Azle, Texas, Nature Communications, April 21, 2015:
* * *
Update, May 17, 2015: It's good to learn that the oil and gas industry takes this problem seriously and wants to find out more. On the industry reaction, see Benjamin Elgin, "Oil CEO Wanted University Quake Scientists Dismissed: Dean's Email," Bloomberg Business, May 15, 2015