Going to a gas station should be fun to get gas for your car. But if you see a tanker truck that is doing their delivery of putting gas in the station's tank, you ought to be aware of what happens:
Gas mixes with water
Read the article carefully.
Because it rarely happens to people, you have to pay attention. When stations are nearly empty, it could most likely have water at the bottom which is heavier than gas. At the same time, water is an engine killer as well.
So, when you see a tanker truck at a gas station, go else where for gas. OR wait until tomorrow to get gas. Give the gas in the station tank time to settle down. Then you can be happy and motor on with a good quality of gas.
Enjoy safe driving!