Just be more selective with your whites. Only pick up lower levels that have potential for higher values (ie daggers axes and lights)

I just did 35 items on a well and its still up, made game public for whoever wants to take it over.

Found a Heavy weapon, then found a well, put heavy weapon in it and poof, well disintegrated... maybe the TierIII heavy weapon was too hard for the level 40+ well to handle.
Other than that, welled a tierVI, side drop was TierVII and well disintegrated (3rd item welled) ... this could also be an indicator.

Personally, there should be a message or maybe an image to indicate that the well has disintegrated.