ᐅ How do I build the exterior stairs to the basement?

Hello,
I have a cellar door on the outside of my house. I still need to build an external staircase to the cellar. I was thinking of pouring a concrete foundation for the cellar stairs and then placing a precast staircase from a concrete plant on top. Now, the sewer connection for the house runs underneath the stairs or the slab. Do I need to take any special precautions, or can I simply pour concrete over it, meaning a blinding layer followed by cement? There is also a branch from the sewer connection here that is intended to be embedded as a drain pipe within the foundation.

Hello,
You can proceed as you described; the sewer connection must not be damaged, so please take care during excavation and concrete work.