My first house was a terrace. A communal footpath, serving all houses ran behind the houses with the back gardens beyond that. The sewer ran under this path. Everyone had their own manhole. It served 7 terraces and the pub on the end. It then ran along to the end terrace, up the side of that into the main sewer. I seem to recall some council or water board obligation whereby if it became blocked they always cleared it without charge.