Earthquakes in AR

It may be possible that some of the recent earthquakes in Arkansas are the result of disposing waste water byproducts from the process of drilling for natural gas. Correlational data indicates that there are more earthquakes in the areas where the injection wells are being used to dispose of the waste water. Arkansas has halted the drilling of new injection wells until further research can be done to verify whether the wells are actually contributing to the earthquakes. However, the companies drilling for natural gas are still allowed to use existing injection wells. Although there is no proof that this is the cause, seismic activity has been increasing near these areas. It would be interesting to know whether the entire state of Arkansas (or even other parts of the United States) have had increases in earthquakes in areas where there is not any drilling. It seems like we should quit using this method of disposing the waste water until the connection between the drilling and the earthquakes is clear.