Deep Disposal Wells

Alberta Oil Peon: ...That's not an atypical depth for deep disposal wells. Usually, such wells are drilled to exploit a brine-laden permeable zone below any potentially productive formations. That's why deep injection wells do have a history of triggering small quakes. The good news is, triggering those small quakes probably releases, more or less safely, pent-up rock stress that, if left alone would eventually let go in a big quake.

Appreciate the (presumably) knowledgeable reply on this. I'd been wondering about the depth on that.

They (whoever They be) did, of course, immediately order shut-down of injections all around that area.