There was a 5.0 earthquake near Cushing, Oklahoma.  There was some damage to downtown buildings.  No people were hurt, thankfully.

Of course, anyone who is involved in oil and gas or who is an environmentalist knows that the speculation will center around disposal wells being the cause.

Disposal wells are used to get rid of produced water, or the water that comes back out of a well after fracking and other stimulation processes.  Disposal wells have been used for almost as long as oil and gas production has been a thing.  Disposal has become a concern in recent years because horizontal fracking creates a lot more produced water than conventional processes ever did.  The theory is that injecting that much water into underground formations is lubricating fault lines, thus making it easier for earthquakes to occur, and also creating pressure imbalances that need to be released, thus making it more likely that an earthquake will occur.

So far, there is only a possible correlation, not an actual cause/effect relationship, between disposal wells and earthquakes.  The correlation is there, but it could just as easily be a coincidence.  Some things are going to be hard to prove, of course.  How do you prove exactly what’s going on thousands of feet underground?

Here in West Virginia, there’s a big water treatment plant being built.  It will handle a lot of produced water, so the produced water won’t have to be injected into the ground.  If disposal of produced water in injection wells is causing earthquakes, it will be less likely to happen here.

Interesting random fact: Cushing, OK is home to one of the largest oil hubs in the world.