Water quality and chemistry The first and foremost consideration in evaluating the suitability of a water source for use in any food processing application, including cleaning, is its potability.While the nations of the world differ in their interpretation of harmful elements, it is safe to say that their primary focus is on precluding pathogenic microorganisms and other toxic substances from waters that are intended for human consumption.A water source that contains no harmful elements and is deemed suitable for drinking is generally considered potable.