Water Treatment: Chem or Filter?

I'm rebuilding a day hiking kit and my question to the brain trust is: Water treatment chemicals (i.e. MicroPUR tabs or something similar) or a small straw filter?

Why?

What say you?

I like filters, faster and more efficient. Even if it's just a survial straw like the Frontier filter. I use a pure hiker most of the time. The Chlorine dioxide tablets don't impress me. They take $ hours to work and in the desert I may not have that much time for myself or an injured person. Plus with thier instructions I feel like I should be wearing a docontamination suit and have hazmat standing by. I use Potable Aqua because it's faster and I'm familiar with them BUT I have had a recent disappointment with them. Bought the kit at wal-mart when putting together a kit for a nieghbor who is a scout. When I openened botlle one I found 21 whole tablets and enough broken pieces for perhaps 6 more for a total of 27 not the 50 it claimed. There were 50 tiny tablets of vitamin c in bottle 2 however. I need to email or call potable aqua and alert them to this.

Based upon the research I did for my own EDC/GHB, i would recommend that you use either or both of the Seychelles "Advanced" straw or bottle purifiers. Light and compact, with very good, test data and on-line comments. BIG BUT, I have no first hand experience with either. I also carry the Katadyn tablets and the Survival Resources Water Bags and their little fold up funnel to hold coffee filters, to pre-filter. The Katadyn Purifier Bottle, ES version, also gets great write-ups. Its a bit bigger and more strongly constructed that the Seychelles bottle, but heavier.

Are you looking for a just-in-case solution or for something that you will be using on a more regular basis?

One has to keep in mind that there are Filters and there are Purifiers.

Your typical camping/hiking filter removes protozoa, parasites, and most bacteria. What it really fails to filter out are the majority of viruses. Viruses like Hepatitis A, SARS, Polio...not nice things.

For that, you need a purification method. While there are combination filters and purifiers, most people rely on after-treatment.

Chlorine dioxide tablets or drops is a very popular after-treatment method. However, boiling will also kill viruses (at sea level 1 minute of boiling time is recommended, at 6500ft+ elevation 3 minutes is recommended).

Essentially, filtration and purification go hand in hand.

However, if I only had room for one, I would make sure I had a method of water purification (like Chlorine Dioxide/Micropur MP-1 Tablets). Why? It will still make water completely safe to drink, you might just have to wait longer for it to be effective. Whereas, your typical filter is bulkier and can still fail to filter dangerous viruses.

Wow! Seriously? I almost bought some of those today but won't now. Not sure I'd trust anything from them again. Thanks for the heads up!



I picked up a Frontier Straw today. I've wanted to try one and figure this is a good chance to try one.

Thanks, Acropolis! I've never done anything but prefilter and boil my water but figure something non-fire dependant is a good idea. This is going to be for just in case. My BOB has some Coglahns disinfectant tabs and my PK has MicroPUR tabs, so I figured going for an alternative was a good idea.

I have 2 Katadyn Purifer bottles that live in my office BIB and our family BOB, as well as a Micro Filter that we use when camping and have ready at home for a bug in situation or longer term bug out. The bottles are just so easy but I hate the spouts on them.

For this kit I definitely want something small, light weight and easy.

Thanks, Izzy. Pre-filter is a must for me too. We have lots of fresh water around but also lots of nasties from industrial pollution. Both sounds like a great idea to me. I got a Frontier Filter today and I carry MicroPUR tabs in my PSK so both it is. Thanks!!

For this kit, just in case, Dennis. And research of course. When I came home with a Frontier filter today, my husband laughed and said "you need help" and then asked to see it. :-)

Thanks, Paul. I'm going to go for a combo solution. For the size, weight and piece of mind!

The 4 hour wait time is only for very cold and opaque water (which is hardest to treat). Water that is clear only needs 30 minutes (same as Potable Aqua)

Here is the treatment chart for MP-1 (Chlorine Dioxide).



It's worth keeping in mind that standard Potable Aqua is an iodine based treatment, and iodine is ineffective against Crypotsporidium. Whereas, Chlorine Dioxide will kill Crypotsporidium. That's why Chlorine Dioxide has become the new standard (and why even Potable Aqua has introduced their own line of Chlorine Dioxide tablets).

Thanks again, Paul. So much to learn!!

I think this the primary reason that chemical treatment makes the most sense after filtration as opposed to before.


My only concern with the chemical treatment / filter straw set-up is that you'd end up doing things in a somewhat backwards manner; you'd have to chemically treat the dirty water and then filter it.

For myself, I'd probably forego the filter straw and simply chemically treat the cleanest water I could collect with a simple pre-filter (bandanna, coffee filter, etc).

" My only concern with the chemical treatment / filter straw set-up is that you'd end up doing things in a somewhat backwards manner; you'd have to chemically treat the dirty water and then filter it.

For myself, I'd probably forego the filter straw and simply chemically treat the cleanest water I could collect with a simple pre-filter (bandanna, coffee filter, etc)."

You may well prove to have the best approach for me too, Denis. I'm going to give this combo a whirl for a while and see how it goes.

I use a Pur Hiker occasionally to process water, but I really prefer to boil. Simple, effective,and you get a nice cup of tea into the bargain.

The worst water I ever treated was stream water in Canyon de Chelly, where we were doing a project that required us to hike in and stay for days at a time. The water was undoubtedly contaminated. There were herds of sheep and dwellings upstream, none of which sported so much as an outhouse. The water (too thick to drink and too thin to plow) first sat overnight to settle the sediment, was decanted and boiled. Over several weeks, this worked just fine - no illness or tummy problems.

Recommendations for boiling times are all over the map. I have seen statements that as much as five minutes of a full boil are required. I seem to do fine just bringing the water to a rolling boil, and then chilling it. There have been times when I have consumed untreated water, figuring that my first priority was to make it back to town, whereupon I could deal with whatever illness might develop. As far as I know, I have never been ill from contaminated water.

Excellent point, Hikermor. 2 birds, 1 stone. Love that approach!



Yuck! But it just goes to show that patience is a virtue, especially in survival.



When my niece was born 13 years ago, they said 5 min. when my son was born almost 9 years ago, they said 10. When my nephew came along 6 months later it was back to 5. When his sister arrived 2 years later it was "just get it to a rolling boil." My MIL says it's all hooey. She may be right, but never got past the 10 mins.

Please clear something up for me, Jac. In the movies at least, the poor hubbie is dispatched to the kitchen to "boil Water" Why? I have done some training (no actual events) in emergency childbirth and I don't recall any specific need to boil... I can understand the need for sterile cloth and wraps, however. Is that why? If that is the case, I believe longer boiling times are justified, five minutes and up, because you are facing different organisms, some of which are quite resistant to heat.

I can't find my latest edition of Medicine for Mountaineering, but I believe the author advocates just bringing the water to a minimum boil, at any altitude for drinking water. He also points out that milk is pasteurized at 165 degrees, well short of boiling (except on the summit of Everest)

So exactly why are we dispatched to the kitchen. To get us out of the way????

Purchase a Higher end (20-30$) Hip flask and carry it to boil water. I May replace the Small tin in my kit with one someday as the one I purchased to do the replacing found its way in my EDC pack filled with vodka. The crazy things that turn out in the end of plans.

Yes. It's to get you out of the way and keep you that way. I think. There was no boiling water when I gave birth but that was in a hospital where everything is sterile. Have to sterilize whatever you cut the cord with? But then, you don't need to cut the cord, just clamp it off, if I remember correctly. Maybe we need an ETS emergency childbirth refresher thread?

We had to boil water for bottles because my son wouldn't latch to breast feed.

Unless we're camping, I usually use either a SS water bottle, SS cup, canteen cup or a can to boil. A flask with vodka sounds like a great addition to our family BOB though!

For years I have extensively and exclusively used Aquatabs.

These tablets are used around the world by .gov organizations, ngo's etc and have a very good track record. The tablets have a 30 minute water contact time and like any other similar products, the cleaner the water to start with, the better.

What I like about these tablets is that they are cheap enough ($8.75 per 50/ strip pack) and have a 5 year shelf life which means there is no reason not to carry these not only for wilderness use, but also having a partial strip pack of 10 or so in the urban PSK only makes prudent sense.

I saw those yesterday, Teslinhiker. I like the price point and the blister packing. One thing I'm Leary of about bottles is the exposure to air every time you open the bottle. A longer shelf life is a good thing in an emergency kit.

These sound easier to use than some of the other stuff I've seen. That's a big plus too!

I've started carrying Aquatabs in my kits as well, and plan to do field testing in late spring. After years of schlepping filters, this seems like a lighter and handier solution.

They only caveat: there are questions about whether it will kill crypto in one of its cyst stages. The manufacturer's old website was clear about this issue, but disappointingly the new website doesn't seem to address it.

From the Globalhydration website (PDF Link)

Cryptosporidium, although these parasites have also been found in humans and other animals. Drinking water sources become contaminated when faeces containing the parasites are deposited or flushed into water. If treatment is inadequate, drinking water may contain sufficient numbers of parasites to cause illness. Other sources include direct exposure to the faeces of infected humans and animals, eating contaminated food, and accidental ingestion of contaminated recreational water.

How can water be treated? Treatment of drinking water for Giardia typically involves some form of high efficiency filtration and/or chemical disinfection such as chlorination. Cryptosporidium has a spore phase (oocyst) and in this state can resist many common disinfectants, notably chlorine-based disinfectants. Because of this resistance, water treatment to eliminate Cryptosporidium generally relies on upon filtration or boiling.

The CDC website also explains more in detail on Cryptosporidium infection risk in an urban or wilderness setting:

- People with greater exposure to contaminated materials are more at risk for infection, such as:
- Children who attend day care centers, including diaper-aged children
- Child care workers
- Parents of infected children
- People who take care of other people with cryptosporidiosis
- International travelers
- Backpackers, hikers, and campers who drink unfiltered, untreated water
- People who drink from untreated shallow, unprotected wells
- People, including swimmers, who swallow water from contaminated sources
- People who handle infected cattle
- People exposed to human feces through sexual contact

CDC links to the description of contaminated recreational water sources and illnesses

Recreational Water: water from swimming pools, hot tubs, Jacuzzis, spas, fountains, lakes, rivers, springs, ponds, streams, or the ocean.

Recreational Water Illnesses (RWIs): illnesses that are spread by swallowing, breathing, or having contact with contaminated water from swimming pools, spas, lakes, rivers, or the ocean.

By reading and analyzing the above info and links, the average person is at risk of Cryptosporidium infection in any urban or wilderness setting. I am not going to give up my swimming or hot tub use at the local community center multiple times per week nor am I going to give swimming in lakes or the ocean. As for treating drinking water while out on the trail? Aside from the low risk of not being 100% against the Cryptosporidium oocyst phase, there are other nasties that are much more of threat such as Giardiasis that most outdoors people need to worry about.

Excellent info! Apparently I didn't drill deep enough into the website.

This statement from the Globalhydration .pdf is particularly useful to me: "Cattle faeces appear to be the primary source of Cryptosporidium, although these parasites have also been
found in humans and other animals." This gives me a good indication of areas where Aquatabs will probably be sufficient, and areas where additional/other methods should be used.

EDIT: The two-part chlorine dioxide products seem to claim full effectiveness against Cryptosporidium. If anyone has information to the contrary, I would appreciate the details. Or thoughts on other drawbacks (aside from inconvenience and leaky vials).

Neither filtration nor chemical treatment will deal with industrial pollution. A charcoal filter will remove some, but not all chemical pollutants. The easiest solution is to carry in your water in that case.

I use micropure for psk type work (small and light). For my day pack I use filtration or sterilization (Steripen) in remote areas. Overseas or below civilization I use BOTH.

There was a good discussion of water treatment recently.

Respectfully,

Jerry

Yes, it is to get you out of the way.

'Quick, I need a glass of water | boiled water | etc' was mentioned as a easy way to get the distraught parent or spouse out of the rescuer's hair and away from stressing the victim in a couple of first aid classes decades ago.

I'm not sure I would follow that advise in this more lawsuit prone age.

I think that for an emergency situation, bleach or commercial chloride-dioxide makes the most sense. Thousands of thru-hikers rely on bleach alone for all their water purification needs for months at a time. Although I haven't thru-hiked in years, I still keep up with the sport and things haven't changed in this regard. While the CDC is probably correct in pointing-out that bleach might not be 100% effective, there has been no clinical research or quantity of anecdotal reports that I'm aware of to make me concerned. A two-ounce dropper bottle will hold enough bleach to treat 300-600 liters of water (depending on whether you need to use two or four drops per liter, which itself depends on how clear and clean the water is to start out).

That said, I still prefer to filter. It is quick, easy and effective. If space was not a concern, I'd pack a good quality water purification filter with a field-maintainable cartridge over any other form of water purification. And I'd still bring the bleach or chlorine-dioxide tablets and a metal cup to boil as backups.

I used the Frontier straws. They seemed to be effective, as I never got sick, in spite of their poor efficiency ratings. The Frontier Pro works better than the cheaper Frontier, because you're not walking around trying to suck out of an open container, and also you can squirt water into a pot for cooking. But these are one-trip devices, and probably not a long trip either. You can also turn the Frontier Pro into a compact gravity-filter setup. Search YouTube if you're interested in that. I actually still have one of these gravity setups in my older vehicle emergency kit.

The SteriPen has interested me for a while. The appeal is it is a small, easy-to-use device, with short treatment cycles that will sterilize all biological hazards in water. My concern is the risk of relying on an electronic device that might fail when needed most, and it doesn't address water taste. But even a filter can fail, hence the need for a backup.

I agree with Jerry.
Filteration removes suspended ( non dissolved) materials
Boiling kills organisms
Chlorine kills organisms

None of the above will remove industrial ( chemical ) pollutants if they exist in the water. Charcoal will remove some, distillation and reverse osmosis will remove most.

For PSK and BOB, if chemical pollution is a concern , carry your own water. And if chemical pollution is a concern in longer survival situations, I would establish a distillation system or rig some small RO unit.

There's lots of industry South of us so the possibility of chemicals in the water makes me nervous, so I prefer to carry my own. Failing that, I'd look for something like water water flowing from the North.

It sounds like the chemical solution is the best one if boiling isn't possible. Thanks gang!

Backpacjac,

Filtration is probably the best for most of North America. I use an old Katadyn pocket filter the most. Crypto is a common problem, virus much, much less so. Some of the new Sawyer filters appear to remove the virus component also. Overseas you are going to need both. None of the chlorine based products will.touch crypto. Chlorine Dioxide (and the miox from MSR) will do it, but only with extended contact time (four hours is common). The Steripen is nice, I have and use one, but it has limits too. The biggest problem is cross contamination, particularly if you use their recommended procedures. It also only does one liter at a time, not much if you want a meal for a group, or to clean up. In canoe country, working from a base camp, I use the MIOX for a large bladder at camp (fill before leaving/bed) and the Steripen for drinking water in the field.

Respectfully,

Jerry

P.s. Boiling is best, I use it in preference to the others when it is practical. The Wilderness Medical Society recommendations (from lots of experimental data) is only to a rolling boil.

Aquatabs sound like a great idea. However, after a quick check, I can't seem to find anyone selling them in the US.

Does anyone know of a US source for Aquatabs? Or, alternatively, does anyone know of a Canadian distributer who would ship to a US address for a reasonable price?

If all else fails, I get down to Seattle frequently, and while there I occaisionally go up to Victoria or Vancouver. I suppose I can get a supply that way.

Mountain Equipment Co-op (mec.ca) sells Aquatabs and they do mail order to the USA. I am not sure if you have to be a member for online ordering or not, but a lifetime membership is only $5.00.

here's a round-up article you might find helpful as a starting point that i wrote a couple years ago called:

Water Contamination Solutions

Thanks, Teslinhiker. I will probably take out a membership and order some. I understand the MEC is the REI of Canada. We stopped in their shop and looked around when we were in Victoria last fall. Looks like a good outfit.

Thanks for the article Wileycoyote. It's clear as mud now! LOL! This is more complicated than I expected. It looks like BYOW remains the best strategy, with boiling the most secure back-up? Failing the ability to boil, it sounds like a combo of fitlering and chemically treating is best.

The big drawback for me with chemicals is the time involved to treat the water. I know ideal situations say the water is good to go in 30 minutes, but realistically the water is probably a bit colder and dirtier than the ideal so I would have the tendency to allow the chemicals to work for closer to 4 hours (the time needed for the 4 degree C, dirty water).

I know people that exclusively use chemicals for their water treatment and the best method seems to be to start treating the water before you need it. This assumes you have multiple water containers and as you empty one, you fill it with local water and throw the chemicals in. Then, by the time you need it the water is good to go.

With regards to boiling, the big drawback for me is that typically you want cold (or at least less than lukewarm) water to drink and cooling down the water after boiling it isn't a quick task.

When I was researching a backcountry water treatment solution for myself, I decided that full purification was what I wanted; I wasn't comfortable relying on filtering alone. I know viruses are a lower risk in North America, but I wanted a solution that could handle both bacteria and viruses.

Ultimately I decided to make my primary water purification system a SteriPen Journey with a pre-filter. This allows me to clean a litre of water in under 2 minutes which is good enough for me. For backup I also have MicroPur tablets and, when backpacking at least, boiling.

And, as Mark M mentioned, this method (perhaps more than others) does necessitate a backup. I ended up getting a defective SteriPen unit which failed in the backcountry. Backups kicked in and it was all good.

Even after getting a replacement SteriPen, they are definitely more sensitive to cold than I'd like so while I am still going to give it a shot this year as my primary purifier, I won't be without backups!

Chemical treatments have the key benefits of being very light-weight and very effective at working with viruses and dangerous bacteria, but they will not remove air compound matter, may not remove all the dangerous parasites present in the water.
So i always keep traditional hiker's water filter is the bottle filter.Lightweight and easy to use.

Speaking from an Arizona/desert perspective, (I note that you are well to the north) the temperature of the water is quite irrelevant if you are truly thirsty.

I guess for drinking water the straw is Ok but it is not especially useful for other things like cooking or washing, or mixing with flavorings.

The pages of discussion here have been very good. I have one or two questions/comments.

If anybody has one of these straws that do filtration - could you actually give us a field test report. I'd really like to know how easy it is to suck water thru the straw. For example, if I place the end of the straw in a puddle of water (cloudy water) and suck on the other end - how fast does water come through?

I have generally used filtration, and especially like Katadyn. The main drawback is that the water needs to have dirt/mud removed first or the pores in the filter will clog quickly.

Iodine tabs and other tabs are probably fine. In a pinch if I was desperate ... bleach too. It's just that the water tastes bad afterwards. You need some discipline to drink a lot of that stuff.

There's nothing wrong with good old fashioned boiling. Can't argue with that. I keep seeing different numbers for how long the water needs to be at a rolling boil.

Pete2

The boiling times are relative. The answer should really be "it depends". It depends on altitude for one. Water boils at 200F at 6,000ft elevation. It boils at an even lower temp as you climb higher. You would need to boil longer vs. shorter at higher altitudes to kill off the nasties.

Particulate matter will also change the formula. If you have some tiny pieces of "stuff" floating around, you basically need to cook these so the internal temperature of that little piece of wood or that little conglomerate of sediment rises to the level needed to kill off the nasties inside that particulate. Think of it as cooking a piece of pork. You need to cook a pork roast longer than a piece of bacon in order to get the internal temp up to a sterilization temp.

" Think of it as cooking a piece of pork. You need to cook a pork roast longer than a piece of bacon in order to get the internal temp up to a sterilization temp."

Good advice. Thanks for that :-)
In my head I'll think of it this way ...
"you're not boiling water - you're boiling soup. Make sure the soup is well cooked."

I'm still hoping someone can report back with a firsthand account of these straws that filter water. It seems like they would clog easily - if there is any suspended dirt or organic matter in the water. But let's see what the folks here say.

Pete2

True, altitude does indeed change the boiling point of water, but I am seeing evidence that water heated to significantly below the boiling point will adequate disinfect same. Let me quote one of my favorite authorities - James A. Wilkerson, MD, Medicine for Mountaineering, 6th ed. , p. 65 - "To eliminate Cryptosporidia, CDC and the EPA recommend boiling water for a full minute (three minutes above 6500 ft or 2000 m because water boils at a lower temperature at higher altitude). [/b] [emphasis added]However,simply bringing water to a boil is just as effective.[b](Milk is pasteurized, which eliminates most organisms, by heating it to only 160 [degrees] for twenty to thirty minutes. Many cookbooks also recommend cooking meat until the internal thermometer reaches 160. See a trend here? If my memory serves me right, 160 F is about the temperature of boiling water on the summit of Everest.

I typically will either just drink the raw water, or bring it to a rolling boil. I have a filter, which I rarely drag around with me, and somewhere in my junk I have various potions and pills to drop into questionable sources. But if I am really concerned about the quality of the water, it's "boil, baby, boil."

A couple of extra comments.
Just for the mountain streams.

I would usually drink the water from fresh streams at high elevations - coming from the snow melt. Just natural water ... no filtration. I never had any problem with that.

I was always suspicious of the water once it descended to the altitude where there were cows grazing. Sometimes they are up quite high - in the high pastures. I didn't usually trust the water at that stage ... without purification. I thought it was probably a personal quirk on my part - I had no evidence that such water was bad. So I found the recent comments on this thread that giardia is coming from the cow patties to be quite interesting.

Finally, I had an offline conversation with Ron Hood one time. It's too bad that he is gone. He was a really good person for survival techniques. I should have taken one (or more) of his courses. Anyway, he told me that it it possible to adjust your stomach to become "resistant" to the giardia. Over time you can condition your body so it does not cause sickness. I would say that it's true - because he didn't give such advice without trying it himself. But also I think that medically it's not good to have a lot of exposure to the giardia - it can cause long-term problems (somewhere I remember reading that).

SO: you can drink from high mountain streams where the water is fresh snow melt. And if you have been thinking about taking a survival course from somebody really good - put it on your Bucket List and GO and do it! These people are not around forever :-)

Pete2

Have you considered UV? Either a pen type or built into a waterbottle

I've looked at those, Teacher and one is definitely on my wish life. Just not in my budget right now.

Picked up a Pristine Pioneer filter straw for my son today. I figure it's the easiest method for him. Water tabs are something I don't think he's ready for yet. (He's nine yo with ADHD.) This way, all he has to do is pre-filter water with a bandana, into his water bottle and let it sit for a while to settle. Then he can drink it with his straw or, if he has/we have one, he can use a fire to boil the water before using his filter straw. We're going to practice tomorrow. It's a pretty simple piece of business, just like my Frontier straw, but better to practice with and get familiar with it before he needs it.

http://www.frontlinewater.com/products/pristine-pioneer-filter

Thanks for all your help guys!

Stealing this for use with my kids and my Scouts. Thanks!

My preference to to filter first then treat with the micro pure product.

I am very lucky in that the water is really good where I live.

Blake