Oklahoma City-based Chesapeake Energy and Clarita Operating of Little Rock have agreed to temporarily suspend use of injection wells (fracking) in central Arkansas where 800 earthquakes have occurred over the past 6 months including a 4.7 magnitude quake

'Fracking' Disposal Sites Suspended, Likely Linked To Arkansas Earthquakes

LITTLE ROCK, Ark. -- Two natural gas companies have agreed to temporarily suspend use of injection wells in central Arkansas where earthquakes keep occurring.

Oklahoma City-based Chesapeake Energy and Clarita Operating of Little Rock told the Arkansas Oil and Gas Commission on Friday that they've stopped operation of the wells near Greenbrier and Guy pending the panel's next regular meeting on March 29.

Clarita's parent company is True Energy Services of Ada, Okla.

The commission says there is likely a link between the wells and the earthquakes. There have been more than 800 quakes in the area in the past six months and a magnitude 4.7 quake – the strongest in Arkansas in 35 years – hit there Sunday.

The high-pressure wells are used to dispose of waste water from natural gas drilling.

http://www.huffingtonpost.com/2011/03/06/fracking-arkansas-earthquakes_n_831633.html