SEWAGE TANKS AND GRINDER PUMP SYSTEMS

摘要

A sewage tank (20, 100, 200, 300) for use with a pump (12) such as a grinder pump to convey sewage. The sewage tank includes a container (21) having an upper portion (24) and a lower portion (22) defining a chamber (30) for containing the pump. The upper portion has a generally constant cross-section and the lower portion has a tapered cross-section to reduce retained sewage. The upper portion and/or the lower portion includes a plurality of vertical ribs (25) and horizontal ribs (27) defining a plurality of recessed pockets (29). The lower portion of the sewage tank may also include an outwardly extending flange (40, 110) sufficiently sized so that soil may be backfilled around the bottom of the tank to prevent the tank from floating upward out of the ground due to its buoyancy under high ground water conditions. A sewage tank having a stepped flange (110) is also disclosed.