Patent ID: 7624892

Claim:
A sewage tank for use with a pump to convey sewage, said sewage tank comprising: a container comprising a sidewall having an upper portion and a lower tapering portion defining a chamber, said lower tapering portion having a reduced size compared to said upper portion; and said upper portion comprising a plurality of intersecting ribs defining a plurality of recessed pockets, and said lower tapering portion comprising a plurality of intersecting ribs defining a plurality of recessed pockets, some of said recessed pockets of said lower tapering portion defined by an outer surface of said sidewall of said lower tapering portion and being entirely surrounded by said intersecting ribs extending outwardly from said sidewall of said lower tapering portion so that said outer portions of said surrounding intersecting ribs define a plurality of openings to said recessed pockets which said plurality of openings is spaced from said outer surface of said sidewall of said lower tapering portion.