Bleach for water???

[mkmangold]

I've asked this before but haven't received a satsifactory answer yet: what about swimming pool bleach? If it works, it would be the cheapest to use and the lightest to carry around since you are essentially not carrying extra water as with Clorox or Purex.

[leaftye]

I've asked this before but haven't received a satsifactory answer yet: what about swimming pool bleach? If it works, it would be the cheapest to use and the lightest to carry around since you are essentially not carrying extra water as with Clorox or Purex.

Did you ask on BPL? I remember this topic coming up a couple years ago, and the answer was that it'd work. Figuring out the correct dosage may take some work though, and it'll help if you're good at basic chemistry.

[swjohnsey]

Calcium Hypochlorite (pool shock) is hard to work with to treat small quanities of water. About 1/2 tsp will treat about 50 gallons of water.

[SunnyWalker]

You might have fun reading the thread: Drinkable Water from a Green Stock Tank.

[Snowleopard]

Aqua mira: When I tried researching this I was offended by their lack of clarity for treating for Giardia and Cryptosporidium. If I remember correctly, the tablets were preferable for Giardia and Crypto because of higher concentration, but I couldn't find precise treatment guidelines (treatment time for various temperatures of water).

Katadyn Micropur tablets: This seemed to be the best of the chemical treatments, primarily because their literature seemed more honest than AM's. It seems to be getting harder to find; Amazon and other online sites have it but not REI or EMS.

Filter plus chemicals: Giardia and Crypto are easy for filters to remove. All the better filters remove bacteria but not viruses. Chemicals, including bleach and aqua mira, do pretty well for killing viruses. So the combo covers everything except chemical pollution. The Sawyer squeeze filter works well on protozoa and bacteria (not viruses) and is light http://www.amazon.com/Sawyer-SP131-P...water+purifier A hiking companion has one and it works well. I'd add aqua mira or bleach for the viruses. Sawyer makes a filter that removes viruses but it is less practical for hiking.

What I use now: boiling when melting snow. When liquid water is available I now use a steripen with micropur for chemical backup if the steripen fails. If my steripen fails I'll probably replace it with the sawyer squeeze plus AM.

What I used in the past was iodine tablets, 2 tabs per liter. After the treatment time vitamin C tabs remove the taste of iodine. I've used this hiking in the US and in 3rd world countries. I've gotten diarrhea in 3rd world travel where I treated or boiled all water, but I think that was caused by food.

[jeffmeh]

Thanks for the citations, and I've updated the post to a stronger condemnation of the 'trusting' method.

I note that what's likely important with respect to hand sanitation is other hikers' hand sanitation, and not letting their hands touch your food (e.g., reaching into your gorp bag). The bugs on your own hands, you already have.

The links are all to observational studies, where they can certainly make statistical correlations. However, their written conclusions are incorrect, as the language they use states causation. An observational study can provide the basis for a hypothesis, and no more, according to the scientific method. The press and some government bodies would have you believe otherwise, but that's sloppy reporting that leads to red wine being good for you on Monday then bad for you on Wednesday.

Now, I would never tell anyone else what to do, but plenty of people treat backcountry water selectively. There is an enormous difference in risk when drinking from a spring emerging from the ground than when drinking from a beaver pond. In between those extremes, with fast running water, it's a gamble given that what lies upstream is unknown.

Of course there is an absolute risk reduction if you always treat water on the AT. However, we do not know the relative risk. Good hygiene, and not sharing food, drink, smoke, etc. likely reduces more risk than treating every water source, but that is only my hypothesis.

[Another Kevin]

Now, I would never tell anyone else what to do, but plenty of people treat backcountry water selectively. There is an enormous difference in risk when drinking from a spring emerging from the ground than when drinking from a beaver pond. In between those extremes, with fast running water, it's a gamble given that what lies upstream is unknown.

Given that there are no prospective studies - and it's hard to imagine how you'd design one given the ethical constraints - I'll go with the data available. The conclusions are no doubt overstated, but it's still the way I'd bet. Your remark that good hygiene reduces risk more is well taken, and possibly explains a good part of the observed association: a hiker who always treats water is one who's aware of sanitation, and likely to be more faithful to handwashing and avoiding shared food and drink. (My working strategy: Treat water and wash hands.)

A further complication. I hike upstate New York more often than I hike the A-T. Many of the places I hike are in karst terrain, where a spring can arise from a sinkhole-fed underground water body with little or no natural filtration. It's fairly common for springs to be contaminated by livestock pastured in their catchments.

I do drink directly from springs that I know to be artesian and arising from a deep stratum. Those are quite safe indeed. Diarrhoea from those is likely caused by high concentrations of Mg(OH)₂ and not by anything infectious. (My daughter once cleaned herself out impressively by drinking from the wrong spring at Saratoga.)

[Lyle]

At which point you have a quart of boiling hot water. You now need to wait hours for it to cool.

Plus, it tastes NASTY, even when cooled down. Until it's been agitated for a day or so to get some of the Oxygen and other gasses back in it that have been driven out by boiling. Boiling as treatment is good for emergencies, or for your cooking water.

I've never been sure why so many folks go to such lengths to find an alternative to tried and true, task specific products. The actual dollar amount you would save seems minuscule given how long the Water purification products - that have all been formulated, tested, produced, and packaged to maintain their effectiveness - last. One set of AquaMira would last a couple of months at least, if you are selective about your water sources and do not treat every source. But even if you do treat every source, they should last a month at least. Just doesn't make much sense to me.

[Colter]

There is an enormous difference in risk when drinking from a spring emerging from the ground than when drinking from a beaver pond.

Hancock et al. (1997) collected 463 groundwater samples from 199 sites in 23 states in the United States; Giardia cysts were found in 14% of the springs.

[jeffmeh]

Hancock et al. (1997) collected 463 groundwater samples from 199 sites in 23 states in the United States; Giardia cysts were found in 14% of the springs.

Is the study available on the net? I would be interested to see the methodology, the sites, the concentrations, etc.

[MuddyWaters]

Be smart.

If getting water out of the ground , at the source, high in the mountains with no human camping or livestock above them, its low risk.
If getting from mountain surface water, streams (runoff that has not filtered thru soil) risk is higher
If getting from areas where human or livestock could have contaminated the water, risk is high
If getting downstream of human or livestock developements, risk is severe.

Use an appropriate treatment for the expected risk.

[Wise Old Owl]

Boiling is not a very good solution.

I agree - however switch to a lightweight wood solution.. is Qwiz

[Colter]

Is the study available on the net? I would be interested to see the methodology, the sites, the concentrations, etc.

Just the abstract apparently.

Crypto and Giardia in US groundwater

Data generated from the detection of Cryptosporidium oocysts and Giardia cysts in 463 groundwater samples were compiled. Samples were taken from 199 sites in 23 of the 48 contiguous states. The groundwater sources were vertical wells, springs, infiltration galleries, and horizontal wells. Samples were analyzed using an immunofluorescence technique. Inclusion of data from all sources showed that 12 percent of the sites were positive for Cryptosporidium or Giardia or both. Cryptosporidium oocysts were found in 5 percent of the vertical wells, 20 percent of the springs, 50 percent of the infiltration galleries, and 45 percent of the horizontal wells. Giardia cysts were found in 1 percent of the vertical wells, 14 percent of the springs, 25 percent of the infiltration galleries, and 36 percent of the horizontal wells. These data suggest that springs are at a higher risk for contamination than vertical wells. Because pathogens occur frequently in infiltration galleries and horizontal wells, these sources warrant further study.

[Colter]

Be smart.

If getting water out of the ground , at the source, high in the mountains with no human camping or livestock above them, its low risk.
...

It is really, really easy to get fooled by whether there is or is not camping or livestock above the source. Last time I got giardia I found out cattle had been in the area, shortly AFTER I drank from the "pristine brook" in the High Sierra.

Giardia, for example, can be zoonotic, spread from wild animals. Many kinds of wild animals carry giardia and other waterborne diseases, including deer, coyotes, muskrats, etc.

That pristine spring with no camping or cattle above it has probably been recently used as a water source by other backpackers, (probably many hundreds along the AT) who have dipped their unwashed hands and water bottles in the theoretically clean water source.

[jeffmeh]

Just the abstract apparently.

Crypto and Giardia in US groundwater

Data generated from the detection of Cryptosporidium oocysts and Giardia cysts in 463 groundwater samples were compiled. Samples were taken from 199 sites in 23 of the 48 contiguous states. The groundwater sources were vertical wells, springs, infiltration galleries, and horizontal wells. Samples were analyzed using an immunofluorescence technique. Inclusion of data from all sources showed that 12 percent of the sites were positive for Cryptosporidium or Giardia or both. Cryptosporidium oocysts were found in 5 percent of the vertical wells, 20 percent of the springs, 50 percent of the infiltration galleries, and 45 percent of the horizontal wells. Giardia cysts were found in 1 percent of the vertical wells, 14 percent of the springs, 25 percent of the infiltration galleries, and 36 percent of the horizontal wells. These data suggest that springs are at a higher risk for contamination than vertical wells. Because pathogens occur frequently in infiltration galleries and horizontal wells, these sources warrant further study.

Thanks for looking. Unfortunately, without information on concentration, viability, or species (as many are host specific), we cannot take much from this. Virtually every water source where it meets the surface will have more than zero giardia cysts, and they may or not pose any significant risk, depending upon the factors above.

Note, that I STILL do not discourage anyone from treating. I do stand by my earlier statements regarding relative risks.

[MuddyWaters]

It is really, really easy to get fooled by whether there is or is not camping or livestock above the source. Last time I got giardia I found out cattle had been in the area, shortly AFTER I drank from the "pristine brook" in the High Sierra.

Giardia, for example, can be zoonotic, spread from wild animals. Many kinds of wild animals carry giardia and other waterborne diseases, including deer, coyotes, muskrats, etc.

That pristine spring with no camping or cattle above it has probably been recently used as a water source by other backpackers, (probably many hundreds along the AT) who have dipped their unwashed hands and water bottles in the theoretically clean water source.

Water is substantially purified percolating thru soil, this is how septic tank systems work.

I grew up drinking from water that came straight out of the ground 70' below my house, the well pump is in the laundry room.
Everyone in the neighborhood also has septic tanks with drainiage lines in their backyards
Result - zero contamination. Rainwater travels thru the soil to the aquifer, but bacteria is filtered out substantially in only a couple of feet.
Water is only run thru sodium chloride bed for ion exchange to remove Ca and Fe (hard water ions) and soften it. It is not filtered, treated, or purified.

Most rural areas operate this way.


When I say spring, I mean where the water comes out the ground. You always follow water uphill and obtain it as close to the source as possible. After that it becomes surface water which is much higher risk, anything could have crapped in the water.

A pristine brook, is surface water. Fairly high risk in my book.

[Colter]

When I say spring, I mean where the water comes out the ground. You always follow water uphill and obtain it as close to the source as possible. After that it becomes surface water which is much higher risk, anything could have crapped in the water.

Springs ARE surface water, even at the source. That's how we can access them. And if I can access the spring, so can other people and animals.

Since many animals are carriers of cysts and oocysts, you should never drink untreated water from even the clearest looking stream or river. Giardiasis became famous as the "backpacker's disease" because so many unsuspecting hikers and backpackers often became ill after drinking water directly from clear, mountain streams. You should also avoid untreated spring water--no matter how clean it looks--because cysts, oocysts, bacteria and viruses may contaminate the spring supply at any time. A properly constructed well is an unlikely source of Giardia and Cryptosporidium because the natural filtering action of the soil removes cysts and oocysts before they enter the groundwater.

A common source of [giardia] infection is water from springs

jeffmeh, I think that giardia being found in 14% of springs is very significant. It shows that springs, widely touted to be the safest drinking sources, are commonly contaminated with giardia, and if they are, there is no reason they can't be contaminated with viable Giardia intestinalis (as they very likely were in many of the 14%).

[MuddyWaters]

Springs ARE surface water, even at the source. That's how we can access them. And if I can access the spring, so can other people and animals.

Since many animals are carriers of cysts and oocysts, you should never drink untreated water from even the clearest looking stream or river. Giardiasis became famous as the "backpacker's disease" because so many unsuspecting hikers and backpackers often became ill after drinking water directly from clear, mountain streams. You should also avoid untreated spring water--no matter how clean it looks--because cysts, oocysts, bacteria and viruses may contaminate the spring supply at any time. A properly constructed well is an unlikely source of Giardia and Cryptosporidium because the natural filtering action of the soil removes cysts and oocysts before they enter the groundwater.

A common source of [giardia] infection is water from springs

jeffmeh, I think that giardia being found in 14% of springs is very significant. It shows that springs, widely touted to be the safest drinking sources, are commonly contaminated with giardia, and if they are, there is no reason they can't be contaminated with viable Giardia intestinalis (as they very likely were in many of the 14%).

getting water from a spring pool, would indeed be surface water.

getting it at the point it is flowing out of the rock, or in best case a pipe jammed in the rock, has little chance of contamination.

you do have to characterize what a spring is.

I grew up in florida. "Springs", are pools there where water flows out of the ground, may be hundreds of feet across, or a couple of feet across. Deep blue clear beautiful cold water. could be full of fish and animals as well.

That is not the kind of spring we refer to when talking about AT water sources though. We refer to a trickle coming straight out the ground or rock that is accessible at that point. It often has a pipe jammed in it to permit easy capture of flow with minimum chance for contamination. Although I have seen a bear drink out of one by licking the pipe..., so other animals probably do too.

Since rocks in mountains are full of cracks, there is always undoubtedbly the chance for contamination as well, as surface water could channel straight into an otherwise good spring. Thats why still dont want any human or livestock activity above them. Risk is never zero, just somewhat less than other sources.

[BuckeyeBill]

Let me start off by saying that I have CHrohn's Disease, an auto-immune disorder of the digestive tract. This caused me to research effective water treatment options very carefully. I finally settled on a First Need XL water filter because it removes both bacteria and viruses from the water. it even removes pesticides and herbicides. Yes it weighs in at 16 oz but as my gastrologist put it, "Carry one pound and be sure or don't and chance getting sick."