So what happens when the reconciliation between litres of fuel pumped in, and litres of fuel sold, shows up a large discrepancy? Everyone just shrugs, and they tack another 5% onto everyones fuel bill? I don't think so.
Underground fuel leaks are serious, and they are treated seriously by the authorities, when discovered. Did you ever see a service station that is suddenly shuttered overnight?
That's because the environmental authorities have suddenly found an underground fuel tank with a serious leak, and the servo operation is shut down on the spot, until the leak is remedied.
Underground fuel leakage is a big No-No. Like a VERY BIG NO-NO. Fuels contain carcinogens, the benzene in petrol/avgas is a well known carcinogen.
Contamination of soils and underground aquifers by underground fuel leakage is NOT allowed, under a myriad of laws - not in the least, the environmental laws.
There are also a myriad of Worksafe regulations and laws relating to underground fuel storage and handling.
Underground fuel leakage poses a very real threat of violent explosion, as volatile fumes from fuel leakage can collect in cavities such as stormwater drains and pits.
If you KNOW for SURE that fuel is leaking underground, from tanks or piping, then call the pollution hotline 1300 130 372 and report the matter.
It is beholden on any manager or person in authority, having charge of an underground fuel storage and pumping system, to ensure that any leakage is found promptly, and that that leakage is addressed by prompt action to stop that leakage.
It is also beholden on any manager to report underground fuel leakage that has caused, or has the potential to cause, environmental harm, to the Qld Dept of Environment and Heritage Protection.
The fines in Australia for environmental pollution via unchecked underground fuel leakage, run into the multiple tens of thousands of dollars.
Guide - Duty to notify of Environmental Harm