Quote Originally Posted by Frög
um no.. the gas is being poured in the tank is stirring up the dirt.. idk how to explain this..

try this:

put sand in a cup, fill it with water.. you will see the sand is all over the place.. let it settle for couple minutes and the sand will be back at the bottom..
Oh, alright. I misread it then. I thought it was talking about dirt from the tanker going into the tank. Thanks for the clarification.