Abstract: A transfer pad in which a central sump is covered with a liquid-impervious membrane. A layer of gravel is then added on top of the membrane. To facilitate monitoring and draining of the pad, a network of perforated pipes is installed within the gravel layer to receive liquids that have filtered through the layer. The gravel layer is then partially covered with concrete, onto which a truck may drive. The layer of gravel may be further covered with a permeable buffer on top of which is added a second layer of gravel. The concrete would then be placed on top of the second layer of gravel. Materials spilled onto the concrete portions of the slab or the gravel are percolated through the gravel layers and collected within the perforated pipes.

Abstract: A transfer pad cover includes a frame structure covered by a water-proof sheet material. The frame structure is supported by bar joists that are mounted for movement along tracks. The entire structure is moved by hand or motor or by a truck from which a liquid transfer will be made to a position adjacent the transfer pad during the transfer operation. When the material and frame structure are sufficiently weighted down so that it is unsafe to move the cover, the joists will rest on a ground surface, preventing movement of the cover. In an alternate embodiment, the rails are sloped and the truck pushes the cover off of the pad. When the truck leaves the pad, the slope of the rails causes the cover to automatically return to protect the pad under the influence of gravity.