Nonclogging impeller is an impeller of the open, closed, or semi-closed type, designed with large passages for passing large solids. Nonclogging impellers consist of large internal openings, and the distance between the shrouds are expanded so large solids will pass through them. They are developed for use in wastewater pumping and to maintain the high level of pumping efficiency. This nonclogging design is capable of handling solids, fibrous materials, heavy sludge and other matter found in normal sewage applications.