Yes, bacterial degradation is a thing, and a great idea.The problem with any degradation process: ozone, hydrogen peroxide, bacteria, can lead to intermediate o

Yes, bacterial degradation is a thing, and a great idea.The problem with any degradation process: ozone, hydrogen peroxide, bacteria, can lead to intermediate or final forms of chemicals that are even worse (more toxic.) Organochlorine chemistry is complicated. The by products are even more complex. And then each of those reactions) effects on the environment are complex. One of the best places to put something at risk is deep in the water, hence deep tailing ponds for acid mine waste, to stop there Oxidation processes. For example surface rust on a car can prevent deeper rust, by creating a non reactive layer. But this is a huge problem! Thousands of barrels, probably other compounds equally or more vicious. The only known way of complete destruction is controlled high temperature incineration - which is expensive, and only certain sites certified to do it.(>1850°C) And of course transport risky. (And if you don't keep control of combustion, then more dangerous side products in the air.) So, for now, best to keep it there, until a complete plan is made. Moving it, touching it, without a that plan, could make it much worse, by mobilising it, exposing to water flows, disseminating it, making it accessible to animals. Quite possibly might be best to bury everything. A horrible thought, but may be the best. It's 3000 meters down! (And this isn't even radioactive!) Just for clarity: not a chemist, but an environmental engineer.