Abstract: The present invention provides a method of making soil substantially impermeable to a chemical compound or composition that may pollute groundwater, comprising applying a polyurethane resin to the soil, wherein said polyurethane resin is adapted to incorporate soil particles into a matrix as it penetrates the soil to make the soil substantially impermeable to said chemical compound or composition. It also relates to a method of containing a chemical compound or composition that may pollute groundwater within a containment structure that has a base formed from soil, a method of forming or repairing such a structure and to containment structures that surround a storage facility for storing a chemical compound or composition.

Abstract: A building structure comprising a footing (21b), wherein the footing (21b) includes a channel (23), and at least one panel (24), wherein the panel (24) is located within said channel (23), wherein the footing (21b) is disposed on a waterproofing membrane (22) which membrane extends along side walls of the footing (21b) and into said channel (23) and wherein the panel (24) has an external waterproofing membrane (25) that is in waterproof engagement with the membrane of the footing (21b) in the channel (23) and wherein the waterproofing membranes (22, 25) comprise an absorptive clay disposed between water permeable layers.