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!