scope:

This European standard is applicable to drain and sewer systems, which operate essentially under gravity, from the point where the sewage leaves a building or roof drainage system, or enters a road gully, to the point where it is discharged into a treatment works or receiving water. Drains and sewers below buildings are included provided that they do not form part of the drainage system of the building. This part sets out the principles and procedures for planning and design of rehabilitation works necessary to achieve prescribed levels of performance for existing drain and sewer systems.