Streams or rivers especially above inhabited areas
Be aware that even water that looks clear can make you very ill. It can still contain germs, parasites and other dangers invisible to the eye.
Remove all visible contaminants using a multi-layered filter.
Purify the clear water using one or more of the following methods:
Boiling – Bring water to a rolling boil for at least three to five minutes. Let cool before using.
Commercial water purifier ($60-200) – Make sure to check what they will purify and what they won’t before using.
Micropur water purification tablets ($9-22) – The tablets will take about four hours to work. Follow directions on the packaging carefully and make note of what they will and will not purify.
Steripen ($40-200) – Water must be perfectly clear for this to work. Make note of what it will and will not purify.
Solar purification – Filter all visible contaminants out of the water using some sort of filter. Place water in a clear plastic bottle. Leave bottle in full sunlight for at least eight hours. Please be aware that this may not remove everything dangerous and should only be used as drinking water in emergencies.
Melt snow – Snow should not have touched the ground or anything else that could contaminate it. If possible use an additional purification process for added safety.