Had an old friend who spent his life pumping fuel in an era when you stayed in your vehicle.
He worked for a large private chain.
One night, as he tells the story, he was called back to his station because the intrusion alarm was going off.
When he arrived, he found one of the partners dumping a drum of an unknown chemical into one of the underground storage tanks.
The local small engine people always claimed they could smell the fuel from this chain and inevitably, the small engine did not tolerate it.
Suspicion was that stuff was being disposed of by being mixed with fuel and that stuff would have cost many $ to deal with as hazardous waste.
Dave