Building Over Sewer Main

Ive got a dilemma I have a sewer main built underneath
my driveway all the way up my property however it is 7" feet to 8" feet
below the ground and im well aware of the proceedure that I have to concrete
encase the pipe but I have an access manhole behind where I want to build,
do I need to encase? as there is only a slab for a garage going over it so it isnt
going to affect the sewer main.

Dont quote me on this but my father approx 6 years ago in vic built a 2 car garage over the sewer and he only had to have an inspection pit at the rear of his garage and not encase it under the slab..

Is there not an Easement or Caveat detailing the sewer main? If so, there would be the restrictions as to what can be laid on top of the sewer main. At a minimum it would be as foc1 said. Don't know if this has been of any help.