Neighbors sewer line is on my property, what can I do?

[Julie Marquez]

I just had a sewer backup at my backyard cottage the other night, but our house was just fine. Come to find out that the side sewer line picks up the cottage, my neighbors house, then our house as it makes it way to the main at the street. Only the cottage and my neighbor had issues. Our cottage tenant vacated and we immediately called a plumber to unclog the line and fix the issue. The next day my tenant comes home and his toilet is not flushing and is bubbling when the other water runs. My neighbor says his sewer is all working okay.

The tenant is out (he was moving out in a week anyway), and I'm still troubling shooting plumbing issues, especially with old 1929 piping out to the street (the cottage piping is new ABS). But if I'm going to fix it right, I am going to separate myself from the neighbor (found out from the City that a new hook up site is easily accessible).

I also found out at our shared sewer line is on MY PROPERTY and I can't find any recording of a sewer easement. Can I kick him off of MY SEWER LINE?