Abstract: Disclosed herein is a device for capturing and retaining fluids such as gasoline which is split while filling a main storage tank, for example, in a gas station. The device includes a manhole having a floor through which the fill pipe for the main storage tank extends, an auxiliary or holding tank communicating with the manhole, and a valve and conduit associated with the holding tank to provide a fail-safe operation of the holding tank. Further, the main fill pipe is provided with a gasket at the juncture where it passes through the manhole floor constructed in such a manner that the standpipe can translate vertically within the hole disposed on the manhole floor due to seasonal change while the integrity of the gasket is still maintained.