The pumped medium is wastewater from the centralized sewerage system of an urban settlement with the characteristic presence of long-fiber synthetic elements (inclusions), the medium is neutral (PH from 6 to 8.5). The content of fibrous, long-fibre inclusions and a wet cloth in the pumped medium is up to 10 m³ per 380,000 m³/day of pumping, which determine the high degree of clogging of the pump impeller (winding on the blades, lumpiness). The content of abrasive particles of sand, small fractions of crushed stone, asphalt crumbs up to 5 mm in size and microhardness up to 9000 MPa in the pumped waste water, by weight, the proportion in the suspension of the pumped medium is up to 30% or up to 100 mg/l up to 150 mg/l extreme, (short-term during the snowmelt season and rains).