It's amazing that the dept of interior denies that fracking causes minor earthquakes called "boomers" politics of plausible deniability.
Since the 1970's, China has injected water into depleting oil fields to keep the "natural" pressure up in the oil reservoir for extracting more oil, "Earthquakes induced by water injection have occurred in four oil fields" - http://voices.yahoo.com/synthetic-earthquakes-5893
Your link does not work to start with. How would adding water pressure to remove oil cause Earthquakes. Taking a fluid out and putting a fluid in. Second how could gas seep into drinking water.That makes nos sense either.