Below ground filter

I'm considering a bottom drain and a double barrel filter for next year.
Ideally I'd like the pump after the filter to maximize muck removal and
eliminate the need for a pre-filter. Unfortunately this would mean putting
the barrels below ground, which would not be my first choice for a number of
reasons. The barrels would be up against the fence, so there's a danger of
caving it in while digging. This is also where the sprinkler pipes run.
:-( The neighbour has a spruce tree on the other side of the fence which
must have some serious roots poking under the fence. Finally, I'm a little
concerned about springing a leak if I just bury the barrels.

Do the solids handling pumps really work or do I still need some sort of
pre-filter? Has anyone else had to dig up their filter to fix a leak? Did
you build a box/room for your below ground filter? If so, what was it made
of?