Due to the extent of buried infrastructure assets to be inspected and managed and the limited budgets available for inspection and rehabilitation, it is necessary to carry out preliminary assessments to establish priorities for this work. Identifying the areas most needing inspection can involve analyzing operational data (e.g. leaks, breaks, quality complaints in water mains or blockages, overflows, backups in sewer systems) but there are also preliminary inspection techniques that can be used that can be used to identify sections of piping that are in poor condition and hence that should have a priority for more detailed inspection. In addition to mirrors, examples of such preliminary inspection equipment are:
- Zoom cameras. These are cameras that can be lowered into a manhole and operated remotely to view along the length of a sewer pipe. Using the zoom feature, a reasonable level of preliminary information can be gathered about the section of sewer pipe that can be viewed from that location. Information such as the presence of infiltration, blockages, pipe wall displacement, pipe settlement, lateral connections, etc. can be rapidly identified.
- Nozzle cameras. This term covers a variety of applications for small, forward facing camera systems that can be deployed in small pipes or incorporated into other types of utility maintenance equipment. Gathering visual images of utility system condition during other operations allows more detailed assessments to be better targeted.