Buried plastic (thin types like bags) doesn't work very well for containment unless you have a pure-sand, no-rock soil surrounding it. Regular soil with rocks against plastic is a guaranteed puncture if there is any movement against the rocks or if there is any pressure applied from above.

The perfect example of this is that black plastic that was often (too often) used as weed barriers and then covered with wood chips or rocks. The moment the first person stepped on the topping, the plastic was compromised, a hole was formed, and weeds would find it like a spaniel after a bird.

And animals will dig them up. And when you dig them up, you would probably rupture them in the process.

I would suggest that you store a few plastic garbage cans and load the bags (or empty them) into the garbage cans, put the lids on and weight them down very well.

Just my opinion, of which I have many....

Sue