PULSE Magazine | September 2018 Issue

Solar Still A solar still is great because it doubles as a water collection method (great for situations where there aren’t any streams, creeks, etc, such as in the dessert) and also a purification meth- od. You will need to have a plastic tarp, but a clear rain poncho would work too. 1. Dig a hole 2. Put grass, leaves, cacti, or any other moisture-containing things into the hole 3. Put a water collection vessel into the middle of the hole 4. Cover the hole with your plastic tarp 5. Put a rock in the center of the plastic tarp so the tarp angles downwards towards the water collection vessel

The idea behind the solar still is that, as the sun shines through the tarp, it will cause moisture to evap- orate from the hole and the things in it. The water vapor will go upwards, hit the tarp, and cool down. This will create a greenhouse effect and cause condensation to form on the bottom of the tarp. The drops of condensation will drip down into the collection vessel. Since the drops are from water vapor, the water should be (mostly) clean.

Build a Grass-Gravel-Charcoal Water Filter There are a few different ways to build these DIY water filters. They all work on the same basic principle though: the water goes through various layers of grass, gravel/sand, and charcoal. During each step, impurities in the water are removed. It is really important that you use charcoal as this is what will absorb the harmful bacteria, protozoa, and viruses. The other materials are more for filtering out big pieces of dirt. If you have spare cloth, then you can build the water filter this way. If you don’t have

spare cloth, then you can make a water filter in a found plastic bottle (luckily, there is usually trash around). If you can’t find a plastic bottle, then you can make a cone out of birch bark for the filter.

Bleach for Purifying Water In urban emergency situations where you are without clean water, bleach will likely be the best way to purify water. The EPA says bleach will kill most disease-causing microorganisms (though it will not remove chemical contaminants). They give these instructions: 1. If the water is cloudy, let it sit so particles settle on the bottom. Only filter the clearer water on the top. Or, you can filter the water through cheesecloth or a coffee filter. 2. Locate some bleach with 8.25% sodium hypochlorite. It should be unscented and have no additional cleaners added to it! 3. Add 6 drops to each gallon of water (2 drops per quart) 4. Let the water and bleach sit for 30 minutes. The water should slightly smell of chlorine. If it doesn’t then repeat the dosage and let it stand for another 15 minutes before drinking.

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