One of the most important engineering systems on the objects of various purposes is the sewage system. It is a system of drainage pipelines, which is designed to remove human waste products, waste water of domestic, industrial or rainfall origin. In the future, all wastewater must be subjected to various kinds of treatment to ensure the sanitary and epidemiological requirements. A distinction is made between indoor and outdoor sewage systems. The effective and smooth functioning of the sewage system depends directly on the practical experience and professionalism of the contractor.