Loose debris and sediment
Flushing may mobilize loose sand, grit and some deposits, but the project needs a plan for where the material goes. Vacuum recovery at a downstream structure may be required to prevent material from moving farther through the network.
Material that may need another method
Roots, hardened deposits, protrusions or structural defects may not be resolved by flushing. A CCTV inspection can help document visible conditions, but any repair decision should be made by the owner or qualified project professional.
Keep the scope specific
Share pipe size, material, length, access structures, known blockages, water supply and disposal requirements. Confirm pressure limits, containment and whether post-cleaning CCTV is required by the specification.