Colorado officials shut down drilling waste well.
http://www.thedenverchannel.com/news/local-news/colorado-officials-shut-down-drilling-waste-well-in-greeley-after-2nd-earthquake-in-less-than-month06242014 (http://www.thedenverchannel.com/news/local-news/colorado-officials-shut-down-drilling-waste-well-in-greeley-after-2nd-earthquake-in-less-than-month06242014)
Injection wells for fracking waste do cause earthquakes.