Fight over fracking comes to fore in California

New Scientist : Hydraulic fracturing âmdash;commonly called frackingâmdash;is a technique for extracting oil and natural gas from underground rock layers by pumping in water mixed with sand and chemicals. Use of the technique has become more common, but has been criticized for increasing groundwater pollution and causing geologic instability. And in California, which is home to the Monterey Shale Formation , concerns have arisen over potential air pollution. The formation is estimated to hold 1900 million tons of recoverable oilâmdash;more than 2.5 times as much oil as in the fields of North Dakota that sparked a boom economy there. However, much of the field is located in densely populated Los Angeles County, which already has high levels of air pollution. A petition was presented to Governor Jerry Brown asking for a statewide ban on fracking, but a bill proposing a moratorium on fracking was recently defeated in the legislature.