A method and system for detecting and identifying location of leaks in an above-ground storage tank (AST) bottom or wall is provided. The method employs a temporary liner on top of the tank bottom or at the interior of another tank surface capable of holding a vacuum. The temporary liner is installed on the top (interior) side of the surface, sealing the liner to the shell and any potential penetrations such as columns. A temporary spacer may be employed to help ensure the liner itself does not seal well to the bottom. A vacuum is pulled between the liner and the tank surface. After the vacuum is pulled, a portable acoustic device is utilized to target noise generated by air entering the vacuum evident of a gas or liquid leak.

A spill containment system is attachable to a riser pipe with an axially moveable seal. The spill containment system allows access to a drop tube in the riser pipe via a removable liquid communication assembly. The spill containment system includes a sealed interstitial space, which remains sealed during installation, service and use of the system. The spill containment system is protected by a weather resistant cover assembly.

An apparatus for providing an interstitial space to the surface of wall, the apparatus comprises: an adhesive layer; a layer of fluid impervious and weather proof material in form of a tape, the tape partially overlapping itself; a layer of spacer material situated between the surface of the tape facing the wall and the surface of the adhesive layer distal from the wall. The spacer material has ends which are encapsulated, the apparatus providing a sealed interstitial space.