Texas oil wells

The EPA believes that there is a "significant possibility” that recent earthquakes in North Texas are linked to oil and gas activity. The state regulators won’t say one way or the other. Texas has thousands of injection and disposal wells that dot state oilfields — underground resting places for millions of gallons of toxic waste from fracking and other drilling activities. It is the third-most at-risk state for man-made earthquakes, according to the U.S. Geological Survey — behind only Oklahoma and Kansas.