Rocky ground and rolling lots make the buried route matter
Shallow limestone and uneven rock ledges in Jonestown make the route and depth of a sewer line important to any repair. A surface view of the yard does not show where the pipe runs, how deeply it is buried, or what rock sits around it. We first work out whether the trouble is limited to one branch or lies farther downstream in the building drain shared by the house.
If excavation is warranted, rock affects access and the effort of opening a trench. It also affects how a replacement section is bedded, supported and set to drain correctly. The visible fall of a rolling yard is not a reliable guide to the fall of the existing pipe, so the line itself needs to be assessed before repair decisions are made.
Roots, ordinary blockage and pipe damage are separate possibilities. Finding the location and condition of the line keeps a recurring sewer problem from being treated as though every backup has the same cause.