Abstract: A flat, flexible, plastic container has an openable and a closed end separated by a sealed region dividing the container into a first and second chambers. The first chamber extends from the openable end to the closed end which contains a filtration assembly separating the first and second chambers. When the first chamber is positioned above the second chamber and filled with contaminated fluid, gravity draws the contaminated water from the first chamber through the filtration assembly to fill the second chamber with filtered water.