Insufficient slope of the sewage pipe

The general contractor or their subcontractors routed the wastewater pipe through the floor slab, and this pipe now had to be modified.

Then I would just nicely refer to the [GU]. It's not your problem if the [AN] of the [GU] messes up. That's why you work with a [GU], so you get everything from one source.

Was the pipeline laid before or after the construction of the shaft?
Were there elevations indicated in the municipality's documents that were subsequently changed?

Has the height of the channels been carried out by the city as planned?
There was a problem in our area where some neighbors had to make additional payments. The original plan had been changed.

The channel of the municipality was already in place; there have been no changes to the plans. The shaft and the pipeline were installed simultaneously.

Then I don't understand the problem. It should have been possible to determine back then that the heights did not fit. I initially thought the pipeline was relocated to the transfer point and afterwards the channel/shaft was too high?