Thanks.
Unfortunately, your questions are part of what I am trying to determine.
The house is old, build in 1972, and the city has no old plans that survived. They microfilmed all paper plans in the 90s to save space, then the bugs ate all the microfilms. So no old record to go back to.
Due to the unique design of the house, there are multiple lines that exit the house. The have already identified and located one of them which is on the other side of the house. I do know these two merge further downstream.
This line I *believe* exits the house under the front door entrance, which consists of a concrete stairway three steps up to the landing areas. This stepped area then is directly connected to the concrete driveway. I believe this line goes under the stairway and landing areas then the driveway. There is no visible exit point elsewhere (I have dugged).
I had someone come by to snake the line and I sort of located it heading in the direction of the stairway by listening to the spinning noise of the snake head from above, but it muffed as it gets deeper. The plumber ran
100' of line but I don't know where it went. I wanted to open the cleanout on the exit end and look down, and possibly snake from there to the city. I also want to send a video down and see the conditon.The entire exercise is to assess the condition of my cast iron line and determine if I need repair, or total replacement.