Abstract: A sewage tank for use with a pump such as a grinder pump to convey sewage. The sewage tank includes a container having an upper portion and a lower tapering portion defining a chamber for containing the pump. The lower tapering portion has a reduced size compared to the upper portion. The upper portion and the lower portion may include a plurality of intersecting vertical ribs and horizontal ribs defining a plurality of recessed pockets. The lower portion of the sewage tank may also include an outwardly-extending flange 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 is also disclosed.

Abstract: A sewage tank for use with a pump such as a grinder pump to convey sewage. The sewage tank includes a container having an upper portion and a lower tapering portion defining a chamber for containing the pump. The lower tapering portion has a reduced size compared to the upper portion. The upper portion and the lower portion may include a plurality of intersecting vertical ribs and horizontal ribs defining a plurality of recessed pockets. The lower portion of the sewage tank may also include an outwardly-extending flange 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 is also disclosed.

Abstract: An underground water storage vessel includes a generally toroidal-shaped hollow body of rotationally moulded plastics with an upright turret having an access port therein. Formed on the outer surface of the hollow body are solid reinforcing ribs in a mesh-like pattern wherein the intersections between the ribs are integrally formed. The underground water storage vessels are installed in reactive soils with a cast concrete ballast extending from an upper region of the vessel via an aperture therein to an interface with a substantially incompressible material, the interface being located intermediate upper and lower regions of the vessel.

Abstract: A sewage tank for use with a pump such as a grinder pump to convey sewage. The sewage tank includes a container having an upper portion and a lower tapering portion defining a chamber for containing the pump. The lower tapering portion has a reduced size compared to the upper portion. The upper portion and the lower portion may include a plurality of intersecting vertical ribs and horizontal ribs defining a plurality of recessed pockets. The lower portion of the sewage tank may also include an outwardly-extending flange 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 is also disclosed.