[GWN7]

The reason he gets the worst of the backup is simple. His sewer connection is lower than yours. Water flows to the lowest point. How do I know this? My neibours and I shared a sewer connection. His was added to my sewer line and his basement was lower than mine so when his wife and daughter would flush their sanitary products it would back up into his first.

$20K sounds excessive to run a new line to your house.