"Link between drilling and earthquakes suspected" by Emily Schmall | Associated Press July 15, 2014
FORT WORTH — States where hydraulic fracturing is taking place have seen a surge in earthquake activity, raising suspicions that the unconventional drilling method could be to blame, especially the wells where the industry disposes of its wastewater.
Fracking, as the procedure is commonly called, generates vast amounts of wastewater, far more than traditional drilling methods. The water is pumped into injection wells, which send the waste thousands of feet underground. No one knows for certain exactly what happens to the liquids after that.
Scientists wonder whether they could trigger quakes by increasing underground pressures and lubricating faults.
Oklahoma has recorded nearly 250 small-to-medium earthquakes since January, according to statistics kept by the US Geological Survey. That’s close to half of all the magnitude 3 or higher earthquakes recorded this year in the continental United States.
Seven small earthquakes shook central Oklahoma in about 14 hours Sunday. They ranged from magnitude 2.6 to 2.9.
A study published this month in the journal Science suggests that just four wells injecting massive amounts of drilling wastewater into the ground are probably shaking up much of the state, accounting for one out of every five quakes from the eastern border of Colorado to the Atlantic coast.
Another concern is whether injection well operators could be pumping either too much water into the ground or pumping it at exceedingly high pressures.
Most of the quakes in areas where injection wells are clustered are too weak to cause serious damage or endanger lives. Yet they have led some states, including Ohio, Oklahoma, and California, to introduce new rules compelling drillers to measure the volumes and pressures of their injection wells as well as to monitor seismicity during fracking operations.
Researchers are debating the appropriate way for measuring the link between injection wells and earthquakes, including at what distances injections can possibly stimulate quakes. Previously, seismologists had linked injection wells to earthquakes occurring within 3 miles of injection sites, but a new study tracks earthquakes as far as 20 miles away from wells.
No injuries or deaths have been reported from these earthquakes, but there have been varying degrees of property damage.
Most of the quakes are big enough to be felt but too small to do damage like classic California or Japanese quakes. In the North Texas city of Azle, which has endured hundreds of small earthquakes since fracking and injection well activity began, residents have reported sinkholes, cracks in the walls of homes, and air and water quality concerns. Two structures collapsed during Oklahoma’s 5.7-magnitude earthquake in 2011.
Studies on the swarms of temblors in central Oklahoma, Ohio, and North Texas have found probable links between injection wells and earthquakes, with the caveat that a dearth of information on conditions underground before the injections began makes it difficult to unequivocally link them to quakes. However, studies more than 50 years old have linked injection wells to tremors in Colorado.
The oil and gas industry officials generally maintain that there is no link between quakes and drilling.
I'm satisfied.
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Shook Globe so hard this print piece fell out the web version:
"North Texas city rejects partial fracking ban" by EMILY SCHMALL, Jul. 16, 2014
DENTON, Texas (AP) — The council governing a North Texas city that sits atop a large natural gas reserve rejected a bid early Wednesday that would have made it the first city in the state to ban further permitting of hydraulic fracturing in the community.
Denton City Council members voted down the petition 5-2 after eight hours of public testimony, sending the proposal to a public ballot in November.
Fracking involves blasting a mix of water, sand and chemicals deep into underground rock formations to release trapped oil and gas. While the method has long stirred concerns about its effects on the environment and human health, industry proponents argue that fracking can be done safely and is cleaner than other forms of energy extraction.
Industry groups and state regulators warned such a ban could be followed by litigation and a severe hit to Denton's economy.
Barry Smitherman, chairman of the Railroad Commission, the Texas oil and gas regulator, said in a letter addressed to Denton's mayor and city council last week that a fracking ban in Denton would "increase America's dependence" on foreign oil and natural gas.
Tom Phillips, a former chief justice of the Texas Supreme Court, representing the powerful Texas Oil and Gas Association, testified that some of its thousands of members would "undoubtedly sue" if the ban eventually passed.
But organizers of the citizen-led petition that — with about 1,900 voter signatures — forced the council to Wednesday's vote, said they proposed the ban as a last resort after fracking operators defied city rules, particularly ones governing setbacks and flarings.
"If the industry had approached anything near reasonableness" in accepting the rules, activists would not have demanded the ban, said Sharon Wilson of the environmental nonprofit Earthworks.
In making a motion to approve the ban, Councilman Kevin Roden argued the "bold move" would force industry to come up with solutions to satisfy citizens' concerns. The motion, however, was not seconded.
The threats of litigation appeared to color how some of the Denton council members voted. Councilman Greg Johnson voiced concerns that lawsuits from the state and from mineral holders could bankrupt the city.
An estimated 500 people turned out to Denton City Hall Tuesday, spilling over into satellite rooms and even a city building across the street. More than 100 people registered to speak during the hearing before the vote.
Among them was Riley Briggs, an 11-year-old Boy Scout, who said he no longer visited a city park after gas wells were installed across the street.
Other petition supporters, some who tearfully addressed the council, said the risks to human health and the environment outweigh the economic benefits.
Denton sits on the Barnett Shale, which is believed to hold one of the largest natural gas reserves in the U.S.
City leaders introduced a temporary ban on new fracking permits in May after fracking-ban proponents delivered a petition containing about 2,000 signatures.
The temporary ban is set to expire in September.
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