I wonder how this would work: First, ignite your water. i.e., burn off any floating combustable contaminants (would this work???) Then filter large junk with paper coffee filters or similar. Then filter smaller stuff with a hiking/backpacking type filter. Add some chlorine. Then get you one of those external aquarium cannister filters that contain a significantly sized carbon cartridge. Not the small ones that hang on top of an aquarium, but the bigger ones that pump several hundred gallons per hour. The one I use on my aquariums holds a good pound or two of carbon (that you buy seperately). Run the aquarium filter on your water in a bucket or something so that the water is recycled through the filter many times. You'll need minimal AC power to run the aquarium filter. A car battery and small inverter should do it. Then desalinate if you have one of those contraptions. Boil the result.

Holy cow! All that for a drink of water. And I don't even know if it would result in something potable.