[masraum]

I've popped the top off the tanks 2-3 times over the last 4 years. The lids are concrete and not buried. I've never seen roots in the tanks, and we've got a pecan tree ~10' from the tanks.

I have no idea if the tank's contents look good or bad. They certainly don't sound like what RF911 described, but they seem to be working. We have a nice long green stripe down the yard from the tank where the grass always grows taller and greener than everywhere else, so I assume that means it's mostly working.