Why roots can return
Cleaning removes root mass from inside the pipe but does not seal the path where roots entered. The maintenance interval and repair choice depend on the pipe condition and how concentrated the intrusion is.
What inspection should record
Useful evidence includes the distance from access, pipe material, joint or crack location, remaining opening after cleaning, and whether other structural defects appear along the run.
Maintenance or structural repair
NASSCO distinguishes operation-and-maintenance findings such as root removal from structural defects. A focused repair, lining, or replacement should be tied to the observed condition rather than the symptom alone.
Sources
- NASSCO PACP condition grading — Sewer inspection condition categories.