DIN EN 13508-1:2013-01

This European Standard is applicable to the investigation and assessment of drain and sewer systems outside buildings. It 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 standard is one of a number of standards which support the general principles set out in EN 752. Drain and sewer systems are part of the overall wastewater system that provides a service to the community. This service can be briefly described as: - removal of wastewater from premises for public health and hygienic reasons; - prevention of flooding in urbanised areas; - protection of the environment. The overall wastewater system has four successive functions: - collection; - transport; - treatment; - discharge. Drain and sewer systems provide for the collection and transport of wastewater. Historically, drain and sewer systems were installed because there was a need to remove the polluted water to prevent diseases. Traditionally, drain and sewer systems were constructed to collect and transport all types of wastewater together, irrespective of the initial source. This led to difficulties in handling the peak flows in times of heavy rainfall and to the introduction of combined sewer overflows, which discharged polluted water to surface receiving waters. Although many drain and sewer systems started out as combined systems there are arguments for considering the separation of foul wastewater and surface water. The pollutant effects are not the same and the separation of effluents allows for the different treatment for each element of wastewater, providing more environmentally friendly solutions. This concept is included in the approach of integrated sewer system management. The committee responsible for this standard is NA 119-05-35 AA "Planung und Betrieb von Abwasserkanälen und -leitungen (CEN/TC 165/WG 22)" ("Planning and operation of sewers and drains (CEN/TC 165/WG 22)") at DIN.