Low Profile, Modular Spill Decks Allow You To Design And Create A Spill Containment System That Meets Your Specific Needs. Spill Decks are available in 1, 2 and 4-drum modules. Modules are easily connected together with bulkhead fittings to allow a virtually unlimited number of customized configurations. The bulkhead fittings not only "lock" connected modules together, but allow spilled liquid to flow from one module to the next.