To minimize water and particulate contamination from entering new drums of oil, it is preferred to keep drums indoors and stacked horizontally. However, when it is necessary to store drums outdoors and uncovered, here is a technique that may be used to remove water from the top of a drum:

Attach a paper towel to the top of the drum. In the accompanying photo, a magnetic clip was used. Allow the paper towel to hang over the edge of the drum so that the water wicks through the towel and down the side of the drum. Water will continue to travel from the top of the drum to the ground, so that breathing of water through the bungs is reduced.