Abstract: A modular container wall unit and containment system formed therewith, each wall unit includes a central panel having wing-like side panels integrally formed on opposite sides thereof and angularly intersecting the central panel at an angle such that, when the side panels of another modular unit are affixed to the central panel of the present unit, and one or more like units are affixed to the second and third units, a chamber is formed which, when combined with a bottom panel and a top panel, defines a container. The central panel of each unit is designed to include recessed areas adapted to mate with the side panel of another modular unit to facilitate the expansion of the system to form an adjacent cell or chamber. Furthermore, the modular unit is configured to withstand lateral loads and maintain system integrity.

Abstract: A concrete storage tank for storing large quantities of fluids, grains or other materials and including a circular tank sidewall formed of a plurality of vertically elongated wall elements having a generally Y-shaped transverse cross-section, a slab floor, a slab roof, a perimeter footing, a perimeter tie beam, and a central tower for access and for housing pumping equipment. In one method of construction the wall elements are formed in place while in an alternative method of construction, the elements are prefabricated at a remote location and then moved into place.