SL - Surface level 6.733
IL - Invert level 4.995
I'd guess that unless the plan is over 30 years old those dimensions are going to be Metres so it looks like its 2.738m deep (approx . . . the depth can vary across the block)
There doesn't seem an offset so the only way to find out how far it is from the fence is look over the fence and see how far the manhole is from the fence.(1.5m from the fence to the pipe is fairly typical)