Susan Biddle Ross is a character on Seinfeld, played by Heidi Swedberg. Susan, an executive at NBC, first appeared in the season 4 episode  The Pitch , in which Jerry Seinfeld and George Costanza pitched the idea for their sitcom to Susan and her fellow executives.
The best solution is to remove the tank and drain it. You can also try and siphon out as much as you can and put STP Gas treatment or any other alcohol based de icer in. It will take several cans of this plus fresh gasoline. If water has reached your fuel filter this will have to be replaced also.
Sweet gas is sometimes available in its natural state, in which it can be used with little purifying. However, if the natural gas from the well contains a higher concentration of the H2S, a suitable gas sweetening process must be used to remove the toxic gas and convert the sour gas into sweet gas.