US Patent 7934619 Cable supported multi-chamber waste water tank

A waste water tank having an inner tank with an inner tank wall; a concentric outer tank with an outer tank wall; a plurality of inner walls extending from the outer tank wall to the inner tank wall, such that the plurality of inner walls divides the outer tank into a plurality of chambers; and a plurality of cables attached to and extending between adjacent pairs of the inner walls, such that the cables provide support to the inner walls when the chamber defined by the inner walls, the inner tank wall, and the outer tank wall is full of fluid and adjacent chambers are empty.