Clean Stock of Water

I know that many countries now are experiencing El Niño phenomenon is a phenomenon also known as the southern oscillation. The El Nino phenomenon can be described as a type of abnormal warming that occurs on the surface of ocean waters in the part of the eastern tropical pacific that is known as the southern oscillation. Some countries are experiencing some water supply shortage and stocking of water is a necessity. We should have stainless steel drums so that we are sure that the water we stock are clean.