3 Days Without Water
The next item up in the progression of the "Rule of Threes" is that a person can only survive 3 days without water. This one comes with a caveat, because you may survive past three days if you have water, but if your water is unsafe to drink, you may only last another few days or weeks. Every year approximately 3.5 million people globally die from waterborne illnesses. Let's discuss how to avoid such a grim fate by learning skills and acquiring equipment so that we may provide this life-sustaining resource for ourselves and those around us.
Filtering, Treating, and Boiling
Filtering is a simple step to remove many parasite eggs, larvea, and even some bacteria. A filter can be easiy constructed even in a wilderness scenario with alternating layers of charcoal, grass and plant matter, and sand. In fact, the Washington County Water Conservancy uses a more technologically advanced version of essentially this exact type of filter.
Some commercially made filters have even reached a level of filtration to be legally considered a water "purifier", meaning that the filter removes enough impurities so as to render water safe to drink without any further processing or treatment required. Examples include the Berkey and ProOne water filtration systems.
Using chemicals such as iodine tablets and chlorine is also an effective way to kill parasites, bacteria, viruses, and algeas that may live in water extracted from the wild. The key to using a chemical treatment process is to memorize the dosage per volume of water to be treated. If too much of a chemical is used, the resulting solution may actually be toxic for humans, but if insufficient treatment is provided the water will still contain some surviving nasties that will, in turn, make you very sick.
The only sure way to kill all of the little nasties that can live in water is to boil and filter the water before consumption. Water must be held at a rolling boil for at least a few minutes in order to kill everything living in it. The recommended process is to filter the water and then boil it. This removes larger impurities, and even some chemicals if charcoal is used in the filtration process, and improves taste. Everything that makes it through the filter is then killed in the boiling process, rendering the water safe to drink. NEVER SKIMP ON YOUR WATER TREATMENT PROCESS.