Fluid storage system

Claim 1

A subterranean fluid storage system comprising a plurality of rectangularly shaped modules of uniform geometry, each module having a height (h) and a width (w) and a length (l), each module including at least two straps encircling said module lengthwise, said straps being spaced from but parallel to one another, each module further including a plurality (N) of rigid core sheets, each core sheet formed from an initially flat rigid thermoplastic material having a thickness (t), each core sheet further characterized by a rectangular height (h) and width (w), each core sheet further including opposed faces with alternate raised land portions and with surrounding valleys of corresponding configuration to provide an overall thickness (T) for each core sheet that is approximately twenty-five times the thickness (t) of the initially flat sheet material, fluid pervious non-woven flexible fabric segments interposed between adjacent core sheets in each module, said core sheets in said fabric segments cooperating to define a laminated stack of length at least N×T, wherein N equals the number of core sheets and T equals the overall thickness of one such core sheet, said fabric segments being relatively thin in comparison to the overall thickness of the core sheets, and said modules being arranged adjacent to one another in a ground excavation, said modules being stacked one on top of another to a height which is in even multiple of the height of each module and wherein additional modules are arranged in side-by-side relationship with said vertically stacked modules, and a fluid pervious fabric material covering said stacked adjacent modules.