Abstract: A triple-walled fluid containment system which includes a rigid metallic outside tank, an outer flexible bladder positioned within the rigid outside tank and a plurality of suspension elements between the tank and the outer bladder for suspending the flexible outer bladder within, and adjacent, the tank. An inner flexible bladder of complementary configuration to the outer bladder is located within, and adjacent, the outer bladder. A vacuum monitoring system communicates with the interstice between the outside and the inside bladder for evacuating the space therebetween.