A method of detecting leaks and measuring volumes as well as a device, the Power-free Pump Module, provides a self-contained leak test and volume measurement apparatus that requires no external sources of electrical power during leak testing or volume measurement. The effluent may be sent to a gasoline pool for blending or the effluent is separated by distillation into an ether stream and either a C8 or a C8-C9 aromatic hydrocarbon rich stream. The delay circuit also includes a controlled delay circuit for generating one or more delayed periodic signals. The side wall partially extends around the top, bottom and intermediate panels to partially enclose the collapsible bag and define a plurality of bays.