In units with a single impeller, one side of the reservoir is sloped to facilitate removal of the collected material. With the double impeller units, it is usually necessary to drain the reservoir for sludge removal. Access door location and interior headroom is provided to facilitate shoveling collected material to a tote box or sludge chute.

Arrangement B is available in ten sizes. Its flat bottom design makes the model ideal for applications with space limitations, especially low headroom.