Fracking and Quaking

By odd coincidence, I just read an article about this today. The concern in Oklahoma is not with fracking - it says that in what you posted. The concern is with pumping left over wastewater back into the ground, and in Oklahoma this is produced mostly by normal drilling, not by fracking. The drills pull up about ten times as much water as oil in Oklahoma at the moment, the majority of which is pumped back into the ground.The people kicking up a fuss include the US Geological Survey, so I don't think it's just whiny environmentalists.

As I just posted upthread, according to what I read today, the problem in Oklahoma is not with fracking, but with fluid injection of wastewater - of which more comes from traditional drilling than fracking. The oil still accessible in Oklahoma comes up mixed with about ten parts water for about one part oil. We now have technology to extract the oil economically, making Oklahoma's oilfields a going concern again where they hadn't been since the '90s, but all the waste water needs to be disposed of, which is done by pumping it back in to the earth. This, according to the USGS, is the cause of Oklahoma's earthquake boom.

It can't be dumped in the water supply, as it's a long way from being clean. The idea of dumping it deep underground is to avoid it contaminating fresh water supplies. Purification technologies are exist, but they are expensive, and completely uneconomical without the amount of water we're talking about.Please bear in mind that my 'expertise' on this matter is based on one afternoon's reading, so that's about the extent of my knowledge on the subject.