endymion wrote:
I put this on gardening but thought people here might know more.

I have a septic tank in the back garden ( its a large back garden. Its
currently covered with grass but the stretch where the tank is is long
and flatish ( slight slope to the right) and did have apple trees on it
once nut those died several years ago. I was wondering if it was OK to
dig up this section of land and put a garden in ? Would I be likely to
disturb anything important ( like drains) by digging round and down from
the septic tank for a garden bed about 100 ft long and 20 feet wide?
I can't imagine this would cause a problem you should have 3-4 feet of
soil before you hit the main body of the tank.
Lift the manhole cover and you should be able to see how far the neck
goes down parallel before opening up into the various chambers.

Bob