A sewerage EJECTOR is nothing more than a pump that pushes the raw sewerage. It can and is used in places where waste can not flow by gravity. For example I have installed several heavy duty federal ejectors ranging from 600 GPM with total discharge head (TDH)of over 60 ft (how high it can pump)
By having your plumber install either simplex or duplex system you can have every drain empty into this system OR just use it strictly for non storm water and thus saving you some electricity.
The great thing about this kind of system your not relying on gravity but the 1 horse power motor to push everything down stream..
Your Master Plumber ( plumbing professional) can size up the exact system right for you.
Good luck