Sewers and wastewater pipes are placed under stress in all phases of their service lives by mechanical/physical and chemical influences as well as combinations of both types of influence. This lecture will present the methodical approach developed in recent years for the evaluation of materials and pipe systems as well as the influences to be expected. Essentially, the materials used in the construction of sewers – concrete and steel reinforced concrete, the synthetics group and stoneware, all of which have their own specific properties and limitations of use – will be considered. In view of its enormous importance for municipal wastewater discharge, concrete will form one of the major items of this lecture. The possibilities offered by high-performance concretes, acid-resistant concretes and composite systems will be explained and placed within the context of structural, operational, static and economic requirements.