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?
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Odigan
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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 2557 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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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
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Ruinar Hrafnakveðja
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Re: Water Treatment on the Trail

Postby Ruinar Hrafnakveðja » Thu Jun 13, 2019 5:25 pm

Great write up, especially your comparison! You reminded me that this is one piece of kit I sorely need.

During our ranging trips we usually travel as a group of 10 or up. We usually travel with 3 or 4 pump purifiers which belong to individual members of our Company. We also have 1 or 2 large hanging bag filters that work very well and are extremely convenient. We use the pump filters when we are on the march, stopping at streams when we need to fill up, and we use the hanging purifiers in camp.

I love the idea of covering the bag filters in period fabrics or leather. But even hanging it away from camp or on the opposite side of a tree would keep the modern out of eye shot. For cooking and cleaning we usually will just boil it, seeing as we would likely have to boil it anyway, as opposed to using purified water.

Kortoso, I like the trick of using the sunlight. I've read about it before when researching survival techniques and things. Unfortunately it has a few strikes against it as a system I could use. While we do get sun up here in Canada, it's not as reliable as it is in other parts of the world. Now add to this the fact that we are typically in deep woodland makes finding direct sunlight for a full 6 hours difficult. Then there's also the issue of carrying plastic bottles into a period camp. Unfortunately it wouldn't work for me, but it's a good trick to know and hopefully it will be useful for some more southern Rangers ;)
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MasterStrong
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Re: Water Treatment on the Trail

Postby MasterStrong » Tue Jun 25, 2019 5:20 am

Our most recent local ranger hike was three folks with two identical (sawyer mini) filters between us. Good thing two of us were set as one set kinda failed. However, that got me thinking about all the various, and best, ways to make water safe on the trail. The Sawyer's are great for our day hikes, where we pack in clean water and refill when needed BUT since my local group is in Colorado, a place where almost anywhere you go was at one time near a functional mine...does anyone have input on heavy metal filtration? I'm comfortable with our occasional trips but if I'm looking at this from a long-term survival standpoint, I don't want to keel over of heavy metal poisoning!
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Harper
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Re: Water Treatment on the Trail

Postby Harper » Tue Jun 25, 2019 5:29 pm

MasterStrong wrote:Our most recent local ranger hike was three folks with two identical (sawyer mini) filters between us. Good thing two of us were set as one set kinda failed. However, that got me thinking about all the various, and best, ways to make water safe on the trail. The Sawyer's are great for our day hikes, where we pack in clean water and refill when needed BUT since my local group is in Colorado, a place where almost anywhere you go was at one time near a functional mine...does anyone have input on heavy metal filtration? I'm comfortable with our occasional trips but if I'm looking at this from a long-term survival standpoint, I don't want to keel over of heavy metal poisoning!


Distillation is probably the safest method. That requires an energy source (fire, electric) and a still.

A mechanical filter like a Berkey would be my next choice. They have different sizes and even a small one used by Special Forces. Size and portability are an issue. I"ve been using a Berkey with both the black and white elements (candles) in my home for years. I can taste and smell the difference between the pre- and post- filtered water. They operate by gravity so no energy source is necessary. For a long term SHTF scenario, get something like this and set back some extra filters.

Pre-filtering with a bandana, coffee filter, etc. may help some, but not enough for what you are talking about. Pre-filtering will also help extend the life of filter elements.
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Re: Water Treatment on the Trail

Postby Peter Remling » Tue Jun 25, 2019 10:02 pm

A handful of activated or regular finely ground charcoal wrapped in clean cotton (new sport sock) will make a decent charcoal filter. If you're in the field use can use the charcoal from your fire. No gray ash just the blackened pieces of wood ground up with a rock will do pretty well in a pinch.
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Odigan
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Re: Water Treatment on the Trail

Postby Odigan » Wed Jun 26, 2019 1:53 am

Berkeys are nice, but their smallest model is still 4x14" and weighs three pounds empty. Something like that would be fine for a base camp, but it really falls outside the "Ranger ethos" on the trail, IMO. There are plenty of compact water purifiers that handle heavy metals, using activated charcoal. The one that comes up often as one of the best of these is the MSR Guardian, though it runs ~$350. On the budget end of the spectrum is the Survivor Pro filter I listed above at $60.
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Re: Water Treatment on the Trail

Postby Iodo » Wed Jun 26, 2019 5:46 am

Peter Remling wrote:A handful of activated or regular finely ground charcoal wrapped in clean cotton (new sport sock) will make a decent charcoal filter. If you're in the field use can use the charcoal from your fire. No gray ash just the blackened pieces of wood ground up with a rock will do pretty well in a pinch.

Someone once told me that carbon or charcoal filters are effective for lead (don't know about other heavy metal ions), I didn't post because I wasn't totally sure
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Odigan
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Re: Water Treatment on the Trail

Postby Odigan » Wed Jun 26, 2019 2:00 pm

Iodo wrote:
Peter Remling wrote:A handful of activated or regular finely ground charcoal wrapped in clean cotton (new sport sock) will make a decent charcoal filter. If you're in the field use can use the charcoal from your fire. No gray ash just the blackened pieces of wood ground up with a rock will do pretty well in a pinch.

Someone once told me that carbon or charcoal filters are effective for lead (don't know about other heavy metal ions), I didn't post because I wasn't totally sure

They are effective at reducing concentrations of heavy metals, including lead. Under laboratory conditions, one can expect ~30-85% reduction depending on the metal and its initial concentration. So, for example, if your source water starts at 30 ppb/ug/L, with a 70% reduction you'll be at 9 ppb/ug/L, which is below both US and EU maximum allowable thresholds for lead (15 ug/L and 10 ug/L, respectively).

Like I said, that's in a lab. In the field... this is what MSR has to say about it:
"MSR filters and purifiers provide microbiologically safe drinking water. The carbon in the filters and disinfectant of the purifiers will adsorb or react with some chemical contaminates such as herbicides, pesticides, and volatile organic compounds (VOCs). However, MSR filters or purifiers will not protect you from high chemical concentrations or heavy metal contamination. Do your best to avoid water sources such as mining tailing ponds or those near agricultural operations."

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