External Drainage (Hydraulics) started

Dropped in today to find that they had started the external drainage and really messed up the slab. Below is a photo of the slab before they started work.

This is after they started work! I hope someone is going 

to clean this before the frame gets installed.

There is soil and broken concrete sewer pipes on the slab. I really don't understand why I'm seeing concrete sewer pipes as I would have assumed this would have been replaced with PVC and encase in concrete. Is it possible the contractors who did the sewer encasement just dumped the old pipes back into the soil? It's certainly not healthy to have all the soil around the sewer pipes on the slab.

The orange conduit is for the electricity and the blue and black tube is probably for water? 

Warning tape, green one says "Caution rainwater line buried below", 

orange one says "Warning warning warning electrical cable below"

  

External drainage complete on this side of the building

Tank slab

 

Mini digger

 The two concrete pits for the hydraulics

Everglas (Evertrench) for the absorption trench

 Gravel for the absorption trench

Chip on the slab in the rumpus room most likely created by the mini digger driving over the slab

Largish chip on the slab in the rumpus room, I wonder if this will need repairing.

 Close up of the chip

Unfinished drainpipe and cracked concrete sewer pipe

Really don't understand why I'm seeing this cracked sewer pipe? 

I'm guessing it's probably not used any more or was damaged while digging and is now bypassed.

The following photos are a bunch of cracked drainage pipes, not sure if this will be an issue or not? 

 Drainage pipes along side the garage

 

The mound of soil dumped at the base of the tree and into the tree protection barrier which I installed. They don't understand the idea of a tree protection barrier?

Shed slab