A convenient and simple process to filter contaminated water using ion exchange resins. You can take any empty container available and set up a primary water filter system. Then, add some chloride to the contaminated water to sterilize. After that, the water go through ion-exchange resins. The final water is pure water, safe to drink. I recommend using addional activated charcoal to adsorb odorous ( if necessary) . Also there should be at least four layers of resins: strongly acidic, strongly basic, weakly acidic, weakly basic or some may call “mixed bed ion-exchange columns” depending on the quality of input water . No energy or power required, flexible and easy to use. Moreover , the resin layers can be changed and ion-exchange beads are not too expensive. However, since it is completed pure water, there is no necessary minerals for human body and this is just a temporary method, for emergency only. Therefore, for long-term using, people should add some nutrient minerals.