If the tanks at the station were not filled that day, the bottom would have sediment and the top may have some stuff that floats. When you fill up, the fuel is being drawn from the bottom of the tank and the sediment should be pretty much be at rest. If you did get some sediment in your tank, that’s what the fuel filter is for. Unless the station was trying to run their tanks dry and possibly run out of fuel, you should get anything that would float. What is bad about running your tank low is the fuel provides lubrication for the fuel pump.