Where have all the earthquakes gone? Kansas.
WHATS IN THIS BLOG:
• Where are the Kansas earthquakes?
• Disposal wells cause earthquakes.
• What about earthquake insurance?
• But earthquakes go along with economic development.
• Regulations that worked.
• Map of earthquakes versus disposal well locations.
I’ve written about earthquakes in Oklahoma, caused mainly by the oil-and-gas industry (see HERE and HERE). The numbers reached their peak in 2015-2016 and have been falling since then due to regulations by the Oklahoma Corporation Commission.
KANSAS REPORTED EARTHQUAKES NEAR THE OKLAHOMA BORDER. Same origin as the quakes in Oklahoma: disposal wells for getting rid of waste-water, which is mainly water produced along with oil and/or gas. The main culprit, in both states, was the Mississippi limestone, a formation that produces oil and LOTS of water in the regions northwest – northeast of Oklahoma City. And yes, it extends into Kansas. The waste-water is usually injected into the Arbuckle lime which sits on top of the Basement, a granite with a lot of deadly faults in it.
Below is an update of the earthquake situation in Kansas, where earthquakes are declining, but also some of the issues that remain. The bullets below are excerpts from a REPORT by Kansas Public Radio on 14 Match 2018 (Brian Grimmett for Kansas News Service). [Words below in parentheses are my own additions.]
• A decade ago, Kansans felt an earthquake only once every few years. Now ground tremors come regularly. One of the hardest hit areas is Harper county in the south-central part of the state. The city of Anthony lies in the middle of Harper county….see map.
• It’s no coincidence, scientists and state regulators agree, that Harper and Sumner counties are also where massive amounts of wastewater have been pumped below ground by outfits drilling for oil and natural gas.
• Between March and August of 2015, more than 2.3 BILLION gallons of wastewater were pumped back into the ground in Harper and Sumner counties. That’s enough to fill about 3,608 olympic size swimming pools.
• WASTEWATER INJECTION WELLS CAN CAUSE EARTHQUAKES, but only if the conditions are right. [For example, a fault has to be in a critical state, meaning at its tipping point, so that injected water which seeps into the fault may lubricate it enough to slip. Then bang! An earthquake!]
• Regulations the Kansas Corporation Commission uses to evaluate new disposal well applications don’t take into account the likelihood of it causing an earthquake. Regulators are focused mainly on preventing one of the state’s more than 4,500 disposal wells from contaminating fresh water. [This can occur if leaks in a disposal well allow waste-water to get into a fresh-water aquifer, meaning groundwater, near the surface.]
• So there’s no rule that demands action be taken to avoid earthquakes until they are already happening.
• [WHAT ABOUT INSURANCE?] Greg Cleveland, mayor of Anthony and an insurance agent, said his company’s never paid out on earthquake insurance claims because coverage only applies to catastrophic damage — things such as the collapse of an entire wall. Cracks in walls and foundations just aren’t that big of a deal. It’s also difficult to prove an earthquake caused them and that it’s not just the regular settling of an old house.
• [BUT EARTHQUAKES GO ALONG WITH ECONOMIC DEVELOPMENT.]
• “It was super alarming, and very scary at first,” said Jan Lanie, an Anthony city commissioner. “Then we kind of got used to it [the earthquakes].”
• Even with the earthquakes, she said, it was hard to not like the economic development the oil and gas boom was creating in her town.
• It’s a trade-off many in the region welcome.
• KANSAS CORPORATION COMMISSION [KCC] PUT A CAP ON THE AMOUNT OF WASTEWATER that could be injected in the area.
• The Kansas Geological Survey has found that since the restrictions went into place in Harper county, the number of detected earthquakes has dropped by more than half.
• From September 2015 to February 2016 the affected area saw 2,263 earthquakes. During that same period one year later the number of earthquakes dropped to 668.
• Cindy Hoedel, who lives in a small town in Chase county in the Flint Hills, became concerned with the issue after she felt an earthquake shake her home.
• She lives more than 100 miles from the epicenter of most of the earthquakes [in Harper County]. But when a company wanted to put a wastewater injection well just north of her home, she and a group of friends filed a protest with the KCC.
• The group needed to show that the well was an immediate threat to the public. Without a history of seismic activity nearby, the commissioners decided it wasn’t.
• THE GROUP HAS ALSO BEEN LOBBYING THE LEGISLATURE to make changes to how the KCC regulates disposal wells. That includes a bill that would expand the injection limits in Harper county [and make them] statewide. But Rick Miller [scientist with Kansas Geological Survey] says that isn’t necessary — the ground isn’t shaking in western Kansas, where huge amounts of wastewater injection is also happening. “It all has to do with the geology,” he said.
• The Kansas Geological Survey continues to monitor earthquakes around the state and are beginning to gain a better understanding of where people should and shouldn’t put new wastewater injection wells. Miller said that he’d recommend against giving a permit to anybody who wants to put a disposal well where they have already seen a lot of seismic activity.
EARTHQUAKES VERSUS DISPOSAL WELL LOCATIONS (KCC Report):
The two images here show the reduction of earthquakes due to two separate regulations on disposal wells:
(1) In March 2015, the KCC set a limit of 25,000 bpd on wells within 5 small separate elliptical areas in two counties: Harper and Sumner. This reduced the number of quakes from 158 to 71 (Magnitude M > 2.5).
(2) In August 2016, the KCC extended the small elliptical areas into one large pyramid shape squatting on the border with Oklahoma. In this larger area, injection rates were limited to 16,000 bpd. The injection rates in the original elliptical areas were kept below 25,000 bpd.
RESULTS: seismic activity dropped from 1,967 earthquakes March 2015 through August 2015 (5-month period immediately after first regulation), to 668 earthquakes September 2016 through February 2017 (5-month period immediately after second regulation). The number of quakes dropped to one-third of what it was.
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