Water Treatment on the Trail

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Odigan
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Water Treatment on the Trail

Postby Odigan » Mon Jan 07, 2019 12:58 am

In days of yore, hardy travelers could confidently drink from any clear source of water without fear of illness. Well... not quite, but it’s safe to say that the old adage “if the cow’s round the bend, the water is fit to drink,” is no longer a good guideline for water quality! Ensuring a safe and clean water supply is of course essential, and creates particular problems in Middle-earth “reenactment,” as it may be the one area where a concession must be made to a piece of modern kit. Without treating on the trail, often the only option is carrying what water is needed, and for anything over a brief day-trip, this becomes unmanageable. My goal here is to look at which methods or products are best for our pursuits; those that are the least obtrusive yet effective, and do not have a high space, weight, or cost penalty.

Aside from creepy crawlies, there are a variety of other contaminants from industrial and agricultural runoff that can be a threat, and even the most remote areas are not immune to them. The ability to remove more than just basic cysts, bacteria, and protozoa is what distinguishes a water purifier from a water filter. Filters do not remove viruses, while purifiers do. Without a lab analysis, there’s really no way to tell what is in your water, or how much of it, so beyond basic decontamination there is some level of assumed risk. Within the US, it’s generally agreed that the likelihood of viral contamination is low – but it is possible. Likewise, there are many places where you may be exposed to varying amounts of pesticides or heavy metals, but is that limited exposure a concern? The answer to that is up to the individual. This is by no means a comprehensive list, but having looked around at numerous reviews and suggestions on light/ultra-light backpacking groups, these are some of those that have come up the most.

Chemical Treatment
In terms of weight, simplicity, and effectiveness, chemical treatment has a clear advantage, while additionally being unaffected by freezing temperatures (freezing water filters is a big no-no). However, this approach does nothing to remove particulates or unwanted chemicals. It can be used in combination with a filter, before or after filtration, and this can be looked at as either overcomplicating things or providing a backup in case of filter failure. Generally, given the minimal size, weight, and cost, chemical drops/tabs represent in terms of their benefit, it makes sense to carry them regardless.

Chlorine dioxide drops or tabs
1-3 oz
15 min to treat water for bacteria, protozoa, and viruses, 4 hours for cryptosporidium
$10-15

Boiling
Almost no-one recommends this as a primary method given the choice, but it is traditional and effective, killing not only the bacteria and protozoa but viruses as well. The downsides are numerous however, requiring time and fuel to boil the water, time for it to cool, additional containers to carry and treat the water, and reliance on a heat source that may not be available or permitted. And of course, again, it does not affect sediments, chemicals, etc. The CDC states that “boiling can be used as a pathogen reduction method that should kill all pathogens. Water should be brought to a rolling boil for 1 minute. At altitudes greater than 6,562 feet (greater than 2000 meters), you should boil water for 3 minutes.”
Cost: $0

Filtration
The broadest and most available category is water filters. There are a variety from the very basic Lifestraw-style to pumps and gravity systems. Some can be used in multiple ways, or are best for individuals or groups. If they include an activated charcoal element they will reduce or eliminate chemical contaminates. Those that I’ve found to stand out for our purposes follow.

Sawyer Mini - If you want the smallest, least expensive, most versatile filter, this one is probably it. However, for a little more money and another ounce, you can double the flow rate. Every comparison I’ve seen suggests opting for the Micro Squeeze over the Mini given the choice.
0.1 micron
1.6 oz for filter alone, 2.5 oz for filter and bottle
1.1 L/min
$13

Sawyer Micro Squeeze
2-3 oz.
0.1 micron
2 L/minute
$30

Katadyn BeFree - A little more in cost and significantly shorter lifespan, I have still seen many people cite it as a favourite over the others.
0.1 micron filter
2 L/minute flow rate
$40

Katadyn Hiker – a good all-around pump. An advantage to pumps is the ability to pull from very shallow sources where it would be difficult to fill a bag.
0.2 micron with activated carbon
1 litre/minute
11 oz. (13.8 oz including bag and accessories)
$50

Purification

Survivor Filter PRO – reviews vary wildly with this one, but it is inexpensive, small, light, and effective.
0.01 micron filter with prefilter and activated carbon
8 oz. (filter only) 11.5 oz (Including sack and hoses)
0.5 L/min.
$60

Steripen
This Elven wonder technically does not “kill” the nasties, but uses UV light to scramble their DNA, preventing them from reproducing, rendering them harmless. It is small and light, but reliant on batteries and it can treat only small quantities of water at a time. Pre-filtering may also be necessary if the water is very cloudy, so again, this is not necessarily the best stand-alone option.
3,000-15,000 litre lamp lifespan
5 oz.
$65-100

Other possibilities

Sawyer Select S1/S2/S3
These are very interesting and give the option of simple and rapid filtration or purification depending on the model, but they do take up significant space (equivalent to a water bottle). I’ve ruled them out personally, but others may be interested.
$50-65

Gravity filters

There are numerous gravity filter systems out there, but I won’t be including them here because I feel they just don’t align well with our needs in this endeavor. I’ve concluded that their combination of size, time to filter, and the requisite hanging of a very modern item in/around camp isn’t appealing. If traveling in larger groups, they become more attractive for their capacity, but YMMV.

Conclusion


If you want to go small, light, and as inexpensive as possible, a Sawyer Mini or Micro Squeeze along with chemical treatment would take care of most everything. This would be about 3-5oz., fit in the palm of your hand, and cost around $25-40.
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Udwin
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Re: Water Treatment on the Trail

Postby Udwin » Tue Jan 08, 2019 12:15 am

Great breakdown.

Odigan wrote:There are numerous gravity filter systems out there, but I won’t be including them here because I feel they just don’t align well with our needs in this endeavor. I’ve concluded that their combination of size, time to filter, and the requisite hanging of a very modern item in/around camp isn’t appealing. If traveling in larger groups, they become more attractive for their capacity, but YMMV.


I'm not terribly familiar with gravity systems, but for large base-camp type arrangements, I wonder how easy it would be to 'reskin' one with a leather cover, cloth-covered tubes, etc. to achieve a more period aesthetic? Similar how some have covered plastic coolers with wooden kegs and such?
Personae: Aistan son of Ansteig, common Beorning of Wilderland; Tungo Boffin, Eastfarthing Bounder, 3018 TA
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Odigan
Silent Watcher over the Peaceful Lands
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Re: Water Treatment on the Trail

Postby Odigan » Tue Jan 08, 2019 3:14 am

Udwin wrote:I'm not terribly familiar with gravity systems, but for large base-camp type arrangements, I wonder how easy it would be to 'reskin' one with a leather cover, cloth-covered tubes, etc. to achieve a more period aesthetic? Similar how some have covered plastic coolers with wooden kegs and such?


They're generally one or two plastic bags of around a gallon capacity (but could be whatever size you want), with an in-line filter. Filters like the Sawyer Mini mentioned above can be used to make a gravity system also. I think their strength would really be serving groups of three or more, where you could reduce overall load and just collect water once for several people.

gravity.jpg
gravity.jpg (13.92 KiB) Viewed 292 times


For a more permanent camp, something like a Berkey would be great to convert to a wooden water keg or somesuch, or wooden kegs could be used with a gravity system directly.
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Kortoso
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Re: Water Treatment on the Trail

Postby Kortoso » Fri Jan 18, 2019 5:15 am

This is a topic much discussed in my old Bushcraft group in California. To wit, I found an interesting article suggesting that indeed, the further you get away from people and cattle, the safer your water may be.
Backcountry water quality tests are good news for campers
and if you want to dig deeper, here is Dr. Derlet's original paper:
https://www.ncbi.nlm.nih.gov/pubmed/16538940

Medieval people DID die from various water-borne parasites, including dysentery and cholera. But these were diseases of settled areas, where people and their stock infected their own drinking water. A ranger, alone, far from the places of Men (and urk-kind), might have found clean uncorrupted water to drink.

Here's a modern purification technique that's worth looking at:
SODIS
Middle Earth Rangers of the Bay Area
Dúnedain Rangers on Youtube
There are no safe paths in this part of the world. Remember you are over the Edge of the Wild now, and in for all sorts of fun wherever you go.

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