ᐅ Wastewater – Drop due to crossing of the maximum static height (MSH)

Hello everyone,

I hope this topic is appropriate here.
In the next few days, a civil engineer will come on behalf of the utility providers to install the electrical and water connections (via the distribution shaft).
I still need to lay a wastewater pipe from the guest bathroom to the inspection chamber (distance about 5m (16.4 ft)) and will have to cross the distribution shaft. The civil engineer told me that they will lay the electrical conduit at 60cm (24 inches) depth and the water at 1.2m (4 feet), so I will have to install my wastewater pipe beneath both of these.

This means I will come out of the house at a depth of 0.8m (2.6 feet), then have about 1m (3.3 feet) horizontally until I reach the distribution shaft, and I will have to go down to approximately 1.5m (5 feet). I assume this can only be done by a drop installation, right? My plan is to slope the pipe from the house at about 2% gradient towards the distribution shaft, then create a drop to 1.5m (5 feet) depth, and continue at 2% slope until the inspection chamber.

1. Is a depth of 1.5m (5 feet) sufficient?
2. Should the drop be installed with two 45° bends at the top and bottom, or just one 90° bend?
3. Are there prefabricated drops with inspection openings? I’m concerned about potential blockages. Alternatively, could I use a PVC pipe with a branch, extend the branch upwards, so that in case of emergency I only need to dig about 20cm (8 inches) from the surface to insert a drain cleaner or spiral? Or would it be better to avoid an inspection opening altogether?
4. Do you have any other comments or suggestions?

Thanks and best regards,

1. The depth is sufficient if the inspection chamber is located deeper and can be connected with a 1° slope (1.7%)
2. 2x45°
3. Close the T-piece and extension at the top with a lid