Originally Posted By: GreeCguy
Back when I was a wee lad of 12 and 13, I worked at a Gulf Gas station. We had a really long stick that was marked with inches which we would lower into the tanks once a week to measure the amount of water in the tank. Before inserting the stick into the tank, we would smear this greasy stuff on the bottom of the stick. If the greasy stuff turned purple, it meant water was in the fuel. If there was water in the fuel, (which there always was), we would get a hand pump and pump it out till no water was left.
I can only imagine that when they came to fill the tanks, any water in the tanks would get mixed with the gasoline and it would then take time to settle back out again, hence the reason that like so many others, when I see the tanker truck at the service station, I pass.
Ding, Ding, Ding! We have a winner! When I was tanking fuel, one of the things a retailer needed to do before taking delivery was to stick the tanks like you stated. If water was above a certain level, either they (or usually the tank supplier) would pump out bottom and get the water out. what got pumped out was returned to the fuel terminal and fed into a separator. We didn't just dump fuel into tanks that had not been checked for both water and the tank level of fuel itself. Kind of a rough deal to start dropping 5000 gallons of fuel into a tank that only has 4000 gallons of available capacity. Environmental hassles are really nasty.
Of any water that may be left in the tanks, it is of such a low volume that it is virtually a non issue. you could have an inch or slightly more in the bottom and in the overall mix it wouldn't make a blip on the radar. we would be talking tenths of one percent kind of thing. For very high volume retailers like commercial truck stops and such, the sticking idea really is not an issue. They get several tank loads of fuel each day. Yes each day. Very little has time to accumulate in storage tanks to be an issue.