I currently have a 2nd floor bathroom that was put together in a remodel before I bought the house. The drain for this bathroom goes straight down to the basement then courses 40' along the basement wall with slight drop then goes straight down into the floor near the corner. It does not tie into my other sewer drain currently and I have no idea where it drains to...other than into the basement floor. It's a shared drain with my basement drains for sinks and under the slab/floor water.
I want to run this sewer line directly out of the house where it comes into the basement and course through the yard to connect with the sewer drain from the rest of the house. The only or main issue is that it would come through the house outside the house above grade. I don't know if it will be a problem for it to come out of the house above grade. I'd much rather put it above grade because the basement foundation wall is 11" thick concrete. Is there any problem with sewer coming out about 1.5" above grade from the house wall? I'm in Washington State and it doesn't freeze much here.