Equipment for the inspection of sewer systems

After reviewing the difficulties in the inspection of underground systems, a simple description of the main items of equipment used is given. All these items exist in the LPC laboratories; some of them have been designed by the LCP. Four areas have been established: (1) A knowledge of the paths and the physical condition of sewage pipes. (2) A knowledge of the hydraulic functioning, with the parameters of level of effluent in the pipes and its rate of flow. (3) The determination of some physico-chemical parameters easily accessible in situ and allowing of a first approximation of pollution content. (4) Existing techniques of recording data in situ. Some examples show how to combine simplicity of resources, quality of response and economy of the investigation through a judicious choice of the technique adopted.