CONVERT THAT MURKY SLUDGE INTO A CLEAN DRINK
Water is one of life’s essentials. It ranks up there right after oxygen as something we cannot, for very long, live without. We need water for digesting our food, for making blood, transporting nutrients and removing waste materials, regulating our temperature, and building cells. Without it, we get weaker, stop thinking clearly, and develop muscle cramps. Eventually, the lack of water will affect your ability to function, and you will die.
You can find water in even the most inhospitable of places, even the desert. Look around. If there are any kinds of plants growing or any animals at all, they all depend on water to survive, which means that water is present somewhere. The trick is to know where to find it.
- Dig into the far bank of a bend in a dry stream bed. Since that is where the water was hitting the bank with the most pressure, some moisture will be farther into the soil there.
- Look for pools of water at the base of cliffs and in shady areas. Water will tend to settle into the low areas and if they are shaded it will last there longer.
- If you see thriving vegetation where the rest of the area is barren and brown then there is probably a subterranean water source there. Dig down in low areas and you might find water, even if it is just moist soil that you can squeeze moisture out of.
- If the area you are in has valleys or canyons check out the north facing slopes of these areas as they receive less direct sunlight and water tends to accumulate there.
- If there are large, flat rock formations in your area check to see if water has collected in depressions on top of the rocks. If they are in a shaded area they can hold water for a long time after a rain has deposited it there.
- The last tip is to keep an eye out for birds, animals, and insects; if you haven’t seen any wildlife for a while and then suddenly you do then you have likely found a source of water. Wildlife would not be there if there wasn’t something they needed in the area. —
Once you have found a source of water you need to do three things; collect it, filter it, and purify it. You can collect it in any variety of things like cups, canteens, water bottles, plastic baggies, or empty beer cans you may find along the trail. A point to remember is to always bring your own water with you and to have something to store it in. If you need to find and treat your water, be sure to have a container for your untreated water and another to drink from for your potable water.
The well-prepared individual or survivalist will have some way to store and purify water. In addition to my normal water supply that I carry in either a backpack reservoir or one liter bottle like you find in the grocery store, I also carry the means to make bad water good; either a pump water filter that will clean out sediment and microorganisms, or chemical pills or drops that will purify the water for me. I also carry a paper coffee filter to take care of the big particulate matter in the water before I try to purify it.
But, sometimes all you have with you is your empty water bottle and what you can see around you. Well, all is not lost and the desert is full of materials you can use to make a DIY water filter that works much like the one you have on your home water faucet or in your emergency backpacking water filter. To make your water filter you will need:
- A knife
- A 1-liter or 2-liter water bottle, preferably clear
- Charcoal (more on this later)
- Large gravel/rocks
- Medium gravel/rocks
- Small gravel or course sand
- Fine sand
- Packing materials (fabric, vegetation, wood chips)
- A piece of cloth
- String or a rubber band
To turn this hodgepodge of materials into a water filter you will:
1. Cut the bottom off a 1 or 2-liter soda or water bottle to serve as a catch basin for your filtered water. You can also use another bottle or container as your storage vessel that you will fill from your catch basin. The advantage of this approach is that you can filter the water more than once if needed to get it as clear as possible.
2. Bore a hole in the bottom of the bottle cap for the water to drain out. You may need to experiment to find the right size hole, but start with a quarter-inch hole and make it bigger if you need to.
3. Place a layer of fabric at the neck of the bottle to serve as a final filter and to keep everything else in place. Hold it in place with a piece of string or with a rubber band.
“IF YOU HAVEN’T SEEN ANY WILDLIFE FOR A WHILE AND THEN SUDDENLY YOU DO, THEN YOU HAVE LIKELY FOUND A SOURCE OF WATER. WILDLIFE WOULD NOT BE THERE IF THERE WASN’T SOMETHING THEY NEEDED TO KEEP THEM THERE.”
4. If you have some kind of packing material you can put it in at this time to keep the charcoal that goes in next from falling out.
5. Add a one inch thick layer of charcoal next. This is where the majority of the filtration takes place and it is also where some purification happens. Charcoal is the black outer layer on a burnt log in your campfire. Scrape it off of the burnt logs and grind it up until it is as fine as you can make it. A caution though, ashes do not have the same properties as charcoal so do not use them in your water filter, all that will do is give you gray water that tastes horrible.
6. On top of your layer of charcoal add a layer of fine sand to serve as your filter for fine particulate materials.
7. Then add a layer of coarse sand to serve as the filter for larger particulate materials.
8. Then a layer of small gravel, and then a final layer of larger gravel as the top layer of your water filter.
9. Each of your layers should be at least one inch thick in order to catch all the materials of the size for which it is designed.
This method works with 1- or 2-liter water bottles but it will also work with larger containers like gallon jugs, plastic barrels, large plastic bags, or metal containers. Anything that you remove the top from, and put a hole in the bottom of will work.
To use your DIY water filter hold the filter in one hand, with the catch basin made from the bottom of the bottle on the ground, and pour the dirty water through the opening in the top and let it filter its way through the various layers to remove ever smaller particulate material from the water. Once it gets to the charcoal there shouldn’t be much of anything left in the water and the charcoal can do its work on the microscopic organisms that might be in it. As mentioned above, make sure you only put dirty water in your non-drinking water container and only put filtered and purified water in your drinking water container.
The charcoal in your filter should catch most of the microorganisms in the water, but it may not catch the smaller ones or the viruses. To take care of them you can use one of the desert’s most abundant resources, direct sunlight. The SODIS method of water purification, short for Solar Disinfecting, uses sunlight to kill the bacteria and viruses in water. To purify with the SODIS method:
1. You put water in clear, colorless, glass or PET type plastic bottles, filled three-quarters of the way up. Colored plastic will block the ultraviolet rays in the sunlight which are what do the actual disinfecting.
2. Shake each bottle to add some oxygen to the water. This facilitates the action of the ultraviolet rays.
3. Then lay it flat and leave it out in direct sunlight. Laying it flat ensures that the same amount of sunlight reaches the water in every part of the bottle.
4. Keep it in direct sunlight for at least six hours, such as from morning to evening, but preferably the whole day. If it is overcast, two days is recommended. —
SODIS has an additional benefit in a desert survival situation because you need to leave the bottle stationary in the sunlight for it to work. This forces you to stay put during the day in a shady area while the water is disinfected, then you can do your travelling at night or at dusk and dawn when it is cooler and there is less direct sunlight to cause you to lose more water.
This two-step process will not remove chemical pollutants in your water, but the filter will remove the particulate material and small organisms from the water. Using the SODIS method will kill the bacteria and viruses that might be in there. Also, if you are in the desert then chemical pollutants are likely not going to be an issue.
Editor’s Note: A version of this article first appeared in the July 2015 print issue of American Survival Guide.