WICHITA, Kansas — On Aug. 16, the second day of the school year, students in the Burrton district felt the shake of a 4.2 magnitude earthquake. They knew exactly what to do: hide under their desks until it stopped.
It was a fairly new procedure, as the district, which is halfway between Hutchinson and Wichita, hadn’t conducted its first drill until the end of the 2018-19 school year.
“They just adapted beautifully,” said Joan Simoneau, the district’s superintendent. “We couldn’t have asked for a better crisis situation, especially on the second day of school.”
Only in the last five years have earthquake drills and damage — one of the Burrton ISD buildings hasn’t been used since August — been a reality in Kansas. A small oil and gas boom dramatically increased the amount of wastewater being injected into the ground, which put pressure on ancient faults.
While experts say the overall trend is declining and the recent spike in earthquakes near Hutchinson shouldn’t last long, some cities are looking for solutions that could lead to more problems.
Under pressure
Before 2015, Kansas rarely experienced seismic activity. The faults that existed were minor, with very little external forces acting on them. Then came a rush on oil and gas, thanks to new technology that allowed companies to extract oil and gas from places where it’d been too hard or too expensive. Increased activity meant more wastewater — a lot more.
Shortly after experts linked earthquakes to increased wastewater pumping, state regulators limited the amount of wastewater that could be put into particularly active zones in south-central Kansas.
When oil prices and oil and gas activity all dropped, so did Kansas’ earthquakes.
But the pressure from water injection, which mostly took place in Harper County near the state’s border with Oklahoma, had a long tail, to the point that it’s impacted faults farther north.
“We see a pressure build, we see a direct correlation with seismicity,” Kansas Geological Survey geophysicist Rick Miller told lawmakers recently. “We see a pressure diffusion and now we’re seeing a drop in seismicity, which is really, really, good news.”
There are a few outliers. Hutchinson, in Reno County, saw a spike in earthquakes in 2019. Miller said he didn’t even know there were faults where the main cluster was centered.
The spike also didn’t follow the normal pattern seen elsewhere. When regulators and experts began looking at injection wells in the area, they found that injection volumes hadn’t increased. But there had been bursts, or pulses, of increased wastewater injection in May and July.
Shortly after, Reno County experienced 4.2 and a 4.6 magnitude earthquakes.
“We’ve admonished (well owners) to not pulse, they’ve asked us, define what a pulse is,” said Tom Stiles, director of the bureau of water at the Kansas Department of Health and Environment.
