ᐅ Building foundation waterproofed with bitumen applied to the base slab

Hello,
we are currently building...
I have waterproofed the concrete slab with bitumen membranes. I left out the areas around the downpipes and the multi-utility connection to avoid damaging the plastic parts. How can these areas be sealed? I was thinking of something like waterproof slurry or applying bitumen...
How did you solve this?

Bitumen or plastic sealing collar applied with cold adhesive (roofing supplies) or KMB (rubber bitumen thick coating). MDS (sealing slurry) does not adhere to bitumen or plastic. Pipe penetrations in the concrete slab must, of course, be waterproof against pressurized water. This is the case with MSpHE conduits, but usually not with self-installed pipe penetrations. All materials must be compatible; adhesives must not dissolve plastics. The sealing should be extended up to the finished floor level.

So, bitumen thick coating is the simplest solution... thank you.