Sewer line above ground in basement

[Adib Rahman]

Hey all looking for some advice, I am looking to buy a duplex that is currently 2 bed 1 bath on each side and one side has the sewer line above ground which is weird. I am planning to add a bathroom and a bedroom down there but was wondering how I'd go about adding the bathroom since the sewer line is above the ground as won't be able to use gravity to do its thing.

The washing machine setup is very weird on that side as the wastewater goes directly into the sump pump, never seen this before.