Using Desert Water- Prefiltering
The pothole in the photo to the left was a welcome sight. It provided plenty of water for the evening and morning meals, and for refilling water containers for the next day's walk. Water from a pothole like this is perfect for purification with the
MSR MIOX Water Purifier; it is clean enough to not require prefiltering. When water is cloudy, when using water from a river such as the Colorado or Green, or after a rainstorm when silt and debris are in suspension in the water, I use a regular paper coffee filter as a prefilter before purifying. The coffee filter is good for many uses- if you have the time to let it dry out it can be packed away and used again and again. If prefiltering is necessary, I usually pour through the coffee filter into a Nalgene bottle and then purify the water. If I use a pump type filter- I prefer the Katadyn Pocket Filter- I attach a prefilter directly to it. The MSR SweetWater SiltStopper works well and replacement cartridges are cheap and lightweight. On river trips I carry a 3 gallon collapsible bucket, fill it in the evening and let the silt settle overnight before filtering. After settling overnight river water is usually clear enough for pumping through a filter, or for purification with the Miox pen. The flow of the river and the time of year may call for more settling time. I have been on the San Juan River after intense rains where water settling overnight still required prefiltering. And the settled water was still more silt than water in the end.
Filtration and Purification- Mechanical and Chemical Methods
Water filters trap contaminants and organisms as the water passes through the filter media. They can be either mechanical, meaning you physically pump water through the filter, or gravity fed, where you fill a reservoir with water to be treated and gravity pushes it through the filter media. Pumping is faster than waiting for gravity to do the job- gravity filters are more suited to river trips than backpacking or hiking trips. All filters will eventually clog. And often, with the silt-laden waters of the southwest, this happens much faster than with clear water from a mountain stream, for example. I use the Katadyn Pocket Filter which has a ceramic element that can be easily removed and cleaned.
Water filters remove protozoa and bacteria. They do not remove viruses, which pass through most filters. Viruses require a chemical means of treatment, boiling, or a filter that contains a purifying element. The First Need Deluxe filter is an example of a water filter that also purifies. It can be back flushed to clean it out, but it cannot be taken apart and washed clean as the Katadyn can. I have seen First Need filters become completely unserviceable due to cloudy canyon water on more than one occasion. Since viruses are not a threat in the desert southwest, the First Need filter would be overkill.
Chemical means of water purification ensures safe drinking water, but often leaves the water tasting like chlorine and does not clean the water of debris. If the water is dirty- cloudy, silty, or muddy, you will first want to filter it through at least a bandana or coffee filter to help make it more drinkable. Some tablets, such as the Potable Aqua system, come with tablets that are added after the purification process to neutralise the chlorine taste. I use the MSR Miox pen which essentially creates its own form of chlorine as you need it. It definitely leaves the water tasting like chlorine. I try to leave my bottle open for a while after purification to let the chlorine gasses escape, pour the water back and forth between bottles if I can, or add flavoring to the water if it tastes too bad. Adding one of the Alacer products- pre-measured packets of vitamin C or electrolytes- effectively removes the bad taste.
Expedient Methods for Finding, Purifying and Filtering Water
In a survival or primitive living situation you may not always have the luxury of purifying your water using commercial filters or chemicals. If you have the means, boiling water will help make it safe to drink, although it may not do much for bad taste. At the very least you can use a bandana, your shirt, or even your hat to filter the water through if it is silty or muddy. You can create a more effective, expedient filter using a bandana, hat or shirt filled with clean sand. Pour the water into the sand and let it filter through into a container. Taking the expedient filter a step further, you could add a layer of charcoal which will not only filter out impurities, but help with taste as well. The expedient filter can be as elaborate as you have the time for, with layers of grass, and alternating layers of sand and charcoal. I will write more on this and post photos in the coming months.
Ultimately you would do better to find water that is clear, cool and clean in the first place. As you can see from the photos above, potholes in slickrock offer a great source of relatively clean drinking water. While I am not telling you that all potholes are sources of completely safe drinking water, I drink from them regularly and have found this to be the case so far. But some precautions are in order.
Drinking From Potholes and Other Unpurified Sources
When searching out potholes to drink from, or when assessing any water source for that matter, I first look for animal tracks and scats. Either of these in or near your water source indicate animal activity- you should move on to another pothole if at all possible. Next ask yourself when was the last rainstorm? If there was rain a day or two before, chances are better for safe water. Relative to this, more shallow potholes are going to have fresher, newer water in them. Take a look at the slickrock after a rainstorm. Then take a look a few days later. In mid-summer most of the holes will have dried up. Deeper potholes will still have water, some even weeks later. But you may find the water a deep shade of green, a cricket or lizard or two floating in it, and maybe even aquatic life inhabiting it. Take a close look at the water- is is clear and cool? How does it smell? Finally, take a look upstream. Make sure there isn't a rabbit or bird carcass 25 feet upstream. I have come across this more than once.
After considering these factors, you might feel better about laying down and taking a drink. And you will likely find some very refreshing, cool water to quench your thirst.
The next source we will consider is a seep or spring. They are basically the same thing- water dripping or flowing from out of the ground, from a canyon wall, or dripping from overhead- called a dripping spring. The difference in classification lies in the size of the
pool of available water. A spring is generally considered to have a pool of water, where a seep may only have a small trickle which may disappear back into the rock a short distance away. Remember that the size of the pool, the amount of flowing water, and the overall quantity and quality of the water can change from month to month, season to season and year to year. A clear, cool flowing spring offering gallons of water this summer may be a trickle next summer.
I have seen dripping springs that must have flowed through 600 feet of sandstone, or more. This is probably some of the purest, best tasting water I have ever drunk. If you find water flowing or seeping from sandstone, even through 10 or 15 feet of it, you can be nearly certain that the water is safe to drink. But as usual, check the water for smell and taste, and look around for signs of contamination.
Flowing water in a canyon bottom is not as uncommon as most people think. Again, it depends largely on the time of year and recent precipitation. Canyon bottom streams are often found flowing over and through sand and gravel, or over slickrock. Remember, these act as great filters for your water. But as always, be sure to look around for signs of contamination. Water in the canyon bottom is as easy for packrats, rabbits, deer, mice, and other animals to get at as it is for you.
We have already discussed the use of river water above. Most southwestern rivers are full of silt and who knows what else from upstream. River water is low on my list of choices for water sources, even in a survival situation. The last thing you want while in an already tenuous position is intestinal problems. But if you must drink river water, try to find a shallow eddy on the river's edge. Look for a location where it flows across sand or maybe through grass, places where it contains less sediments and is possibly a bit cleaner.
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