Abstract: A spill deck module includes a substantially planar bottom wall, a pair of opposing side walls and a pair of opposing end walls which form an interior chamber. Each side wall and end wall includes an aperture allowing fluid communication between adjacent modules. Initially, the side wall and end wall apertures are closed by a removable sealing assembly. When a number of modules are desired to be arranged to form a composite spill deck, the sealing assemblies in adjacent modules are removed and replaced with module connection assemblies allowing fluid transfer between adjacent modules. A deck grating either rests on the bottom surface of the spill deck or rests on top of ribs provided in each module. The grating forms a continuous spill deck for support of containers of hazardous or non-hazardous liquid materials in various configurations using different combinations of the spill decks.