Thanks for the replies, the waste is indeed going into a gulley next to the property currently.
What I plan to do is have all the waste connections sorted above ground and then swap the existing clay underground pipe with a new PVC one so that just one pipe goes into the chamber with no...
I plan on cutting into the existing clay pipe before it enters the inspection manifold and coupling it to a pvc underground pipe which will collect the waste from the new toilet and existing bathroom utilities.
I'm planning to add a toilet to an existing bathroom that just has a bath and sink.
The underground pipe goes through this inspection chamber and turns through an angle of about 70-80 degrees. Is this likely to cause an issue if effluent is discharged into it?