Industrial sites have particular challenges among them are: manhole access points are difficult to locate or are not found, onsite drawings can be out-of-date or missing information, presence of debris in the line, high flow levels can prevent adequate viewing of the pipe circumference, aeration can compromise sonar data and water temperature may be to hot for the electronic equipment. Despite these difficulties some information can be acquired.

Chemical Corrosion: if the process is not identified and addressed the sewer main may deteriorate to such an extent that it is in danger of collapse.

Debris Accumulations: debris accumulations in sewer mains are highly undesirable as they restrict the hydraulic capacity of the main and can potentially lead to blockages and sewer back-ups.

Infiltration: infiltrating ground water migrates through defects and open joints and significant quantities of fine material surrounding the pipe is removed and transferred into the main. This in turn causes the pipe/soil structure to weaken and provides the opportunity for further structural damage to develop.