Bleach for water???

[DaTwiztedOne]

Hi yall, new here, not new to outdoors and camping and "some" day hiking, the wife and i are working on doing some section hikes on the AT. anyway getting to the point of question... i read on a state web site that all you needed was bleach below is what it said.



If boiling is not possible, treat water by adding liquid household bleach, such as Clorox or Purex. Household bleach is typically between 5 percent and 6 percent chlorine. Avoid using bleaches that contain perfumes, dyes and other additives. Be sure to read the label.
Place the water (filtered, if necessary) in a clean container. Add the amount of bleach according to the table below.
Mix thoroughly and allow to stand for at least 30 minutes before using (60 minutes if the water is cloudy or very cold).





Treating Water with a 5-6 Percent Liquid Chlorine Bleach Solution



Volume of Water to be Treated

Treating Clear/Cloudy Water:
Bleach Solution to Add

Treating Cloudy, Very Cold, or Surface Water: Bleach Solution to Add



1 quart/1 liter

3 drops

5 drops



1/2 gallon/2 quarts/2 liters

5 drops

10 drops



1 gallon

1/8 teaspoon

1/4 teaspoon



5 gallons

1/2 teaspoon

1 teaspoon



10 gallons

1 teaspoon

2 teaspoons






anybody done it this way???

thanks

[Feral Bill]

Several people here swear by this method. However, bleach WILL NOT KILL PROTISTS, SUCH AS GIARDIA AND CRYPTOSPORIDIUM. Please see the endless discussion of water treatment in earlier threads. Bleach is recommended for emergency treatment of household water, primarily because people usually have some.

[leaftye]

Ugh, this again.

Bleach can work for giardia at room temperature, but requires much more drops than usual--30 per liter. Effect of Chlorine on Giardia lamblia Cyst Viability (http://www.ncbi.nlm.nih.gov/pubmed/7235695).

Bleach doesn't seem to work with Cryptosporidium though, not even with much higher concentrations of chlorine than is found in household bleach. Effects of Ozone, Chlorine Dioxide, Chlorine, and Monochloramine on Cryptosporidium parvum Oocyst Viability (http://aem.asm.org/content/56/5/1423.full.pdf)

[Colter]

Ugh, this again.

Bleach can work for giardia at room temperature, but requires much more drops than usual--30 per liter. Effect of Chlorine on Giardia lamblia Cyst Viability (http://www.ncbi.nlm.nih.gov/pubmed/7235695).

Bleach doesn't seem to work with Cryptosporidium though, not even with much higher concentrations of chlorine than is found in household bleach. Effects of Ozone, Chlorine Dioxide, Chlorine, and Monochloramine on Cryptosporidium parvum Oocyst Viability (http://aem.asm.org/content/56/5/1423.full.pdf)

Thank you for quoting scientific papers. This paper (https://docs.google.com/viewer?a=v&q=cache:xRzk949QAsMJ:dwi.defra.gov.uk/research/completed-research/reports/dwi0739.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESgPctqC-iDAmiIau4CrLo5MOMsZE7N_sFzDYuEgK2t4n5XUZQjCsMD8a1J C4IY1Gp9ocAL2M-rC6xUJf0H1JZL_SQPxBd-2hmzi2gpZe-8F9dYI2M_hxr65aCSnei4v-Hwimfe6&sig=AHIEtbSLVvKBZ2Q2PmuiALrmXBh3_6J3EA), by my reading, says that if you wait long enough (4 hours) standard chlorine treatment works very effectively for giardia even in 41 degree water. At 30 drops per liter it would kill all the giardia cysts in 10 minutes in 41 degree water. Seems wiser to find room temp water or warm the water up to room temp and use much lower amounts of bleach. Better yet, rely on a water treatment method that kills crypto, too!

[leaftye]

Thank you for quoting scientific papers. This paper (https://docs.google.com/viewer?a=v&q=cache:xRzk949QAsMJ:dwi.defra.gov.uk/research/completed-research/reports/dwi0739.pdf+&hl=en&gl=us&pid=bl&srcid=ADGEESgPctqC-iDAmiIau4CrLo5MOMsZE7N_sFzDYuEgK2t4n5XUZQjCsMD8a1J C4IY1Gp9ocAL2M-rC6xUJf0H1JZL_SQPxBd-2hmzi2gpZe-8F9dYI2M_hxr65aCSnei4v-Hwimfe6&sig=AHIEtbSLVvKBZ2Q2PmuiALrmXBh3_6J3EA), by my reading, says that if you wait long enough (4 hours) standard chlorine treatment works very effectively for giardia even in 41 degree water. At 30 drops per liter it would kill all the giardia cysts in 10 minutes in 41 degree water. Seems wiser to find room temp water or warm the water up to room temp and use much lower amounts of bleach. Better yet, rely on a water treatment method that kills crypto, too!

I read that the same way, but I'm not clear on how they prepared the stock solution of chlorine (2.5). I doubt they used 100% sodium hypochlorite. They're probably using some convention I'm not aware of, and it could probably be figured out with the calculator below.
http://www.handymath.com/cgi-bin/chlorined3.cgi

[TheYoungOne]

Katadyn Micropur Water Purification Tablets are Chlorine dioxide and they claim to destroys viruses and bacteria in 15 min., Giardia in 30 min. and Cryptosporidium in 4 hrs. However the EPA, CDC, and Ready.gov all say that while bleach is very helpful in purifying water, BOTH iodine and bleach may have a tough time completely killing Crypto in water.

http://www.cdc.gov/healthywater/drinking/travel/emergency_disinfection.html

Another thing to think about is that bleach has a shelf life. After 6 months its starts to get less potent, and a year old bottle can be 20% less effective then a fresh one

http://www.scripps.edu/newsandviews/e_20060213/bleach.html

[swjohnsey]

I was playing with calcium hypochlorite for water purification and decided to test water that was treated with household bleach for residual chlorine. To get sufficient residual in clear water it was taking 2 or 3 drops per pint. This is more than what I usually use. I was alway taught 1 drop/pint clear water, 2 drops/pint cloudy water. I would probably double that now.

[Wise Old Owl]

after several days of drinking the iodine treatment and not knowing as I was in a group a few years back ... I was sick... Iodine is not good for everyone... I carry Micropur now.

[DaTwiztedOne]

thanks for the replys, i went back and searched the site for more posts about water, some interesting reading, so it looks like the tabs in the water at night when they can sit all night and boiling the water during the day to top off bottles looks like the best route to go......

[swjohnsey]

Boiling is not a very good solution.

[DaTwiztedOne]

now why not? everywhere i read it says to bring to a boil for at least 1 minute to kill everything..... what did i miss now?

[swjohnsey]

I works O.K. but it takes lots of time and fuel. Put a quart of water on your stove a time how long it takes to come to a rolling boil. You are gonna stop for water many, many times. I think anything would work better, filter, Aqua Mira, Steripen.

I use bleach when I treat water which is not very often.

[DaTwiztedOne]

ok i see what you are talking about, ive timed it for us (2) it takes 7min on my alcohol stove to boil 4 cups of water...

[Feral Bill]

ok i see what you are talking about, ive timed it for us (2) it takes 7min on my alcohol stove to boil 4 cups of water... At which point you have a quart of boiling hot water. You now need to wait hours for it to cool.

[Another Kevin]

There are a lot of threads on the subject here on WB. What is both popular and fairly safe:

Aqua Mira drops. These are chlorine dioxide, not elemental chlorine. Used as directed, they are effective against viruses, bacteria, Entamoeba, Giardia, Cryptosporidium. (The literature is somewhat spotty about ClO2 and Cryptosporidium.) They are extremely lightweight. The disadvantage is that for extensive travel, they're more expensive than the other solutions, and you can't drink right away - they take time to work. You need to wait some minutes after mixing the two-part chemistry before adding it to the water, and then wait 20 minutes (room temperature water) to 4 hours (freezing cold water with heavy Crypto contamination) before drinking. The treated water often has floaties - bits of debris - unless you strain it through a bandana or something.

Polar Pure iodine (discontinued). Effective against viruses, bacteria, Entamoeba. Moderately effective against Giardia. Possibly ineffective against Cryptosporidium. Takes time to work. Requires chemical resupply only very infrequently - one container will surely last a thru-hike. Unlimited shelf life. Used to be extremely inexpensive. The container is glass, so you have to be a little careful. Leaves brown stains if you get it on anything. Imparts an objectionable taste to the water. People with iodine sensitivity or thyroid problems can't use it. It's now virtually unobtainable, owing to a DEA decree that made it unlawful to sell it without onerous paperwork: essentially, elemental iodine is treated as an illegal drug in the US. The manufacturer was forced out of business after the meth labs started buying outfitters' entire stocks of Polar Pure and extracting the iodine for use in meth production.

Filters such as the ones from Sawyer, MSR or Katadyn. Effective against bacteria and all the protozoa. They are ineffective against viruses, but the waterborne virus hazard in the US is minimal. You get to drink immediately. They're heavy - often half a pound to a pound - but often the pump and intake hose make it easier to collect water, and they get rid of floaties, so the weight of a pump filter might be justified. Filters are questionable in winter conditions because you can't let them freeze: if the filter element freezes, it is untrustworthy and must be replaced. They're the method that's least likely to impart an objectionable taste, and some of them - particularly the ones that include activated charcoal post-filters - can actually improve the taste of the water.

Steri-Pen: Effective against viruses, bacteria and protozoa. Works fast. Heavier than drops or tablets, but lighter than a filter. Has a lamp that can break, an electronic package that can fail, and batteries that can go dead. A disconcerting number of people here report failures in the field.

MiOX (discontinued): Another interesting idea that didn't last and is now unobtainable. The idea was that it was a small (penlight-sized) electrolysis rig that made mixed oxidants (chlorine, hypochlorite, chlorine dioxide) in the field. The only chemical supply it needed was table salt. Like the Steri-Pen, it had batteries and electronics that can fail. It's now discontinued.

Tablets of various sorts: Most hikers consider these useless. Either they're ineffective against one or another common organism, or they have a short shelf life, or both. Don't just check the expiration date on the bottle: many tablets have a shorter shelf life after opening, so read the fine print. In particular, iodine tablets that have turned orange or brown are worthless and must be discarded. Chemistry and efficacy vary by brand.

Boiling: Effective against all waterborne organisms. Takes a long time (you have to stop, unpack your stove and cook kit, boil the water, and wait for it to cool enough to drink). Takes a prohibitive amount of fuel in most situations. An exception is winter travel, where snow may be the only available water source. If you're melting snow anyway, you might as well take a few minutes longer and boil the water.

Trusting: A number of posters here claim that, at least on the AT, if you're reasonably careful about your choice of water sources, the hazard from contaminated water is overrated. Nevertheless, a 2003 study (http://www.ncbi.nlm.nih.gov/pubmed/12681456) of Appalachian Trail hikers found that diarrheal disease is the commonest medical problem limiting a thru-hike, being even a worse scourge than Lyme disease. (It's still not a top reason for quitting: the top reasons cited were injury, lack of time, and psychosocial reasons.) Are you feeling lucky, punk?

What I do: In hot weather, if I expect that I might arrive at a water source thirsty, or if I expect that water sources might be hard to collect from, I carry a filter. Knowing that I can drink moments after getting to water, and that I can suck up water with a hose, is worth the weight to me. If I expect freezing conditions, then the filter stays home and I carry Aqua Mira. If I'm melting snow anyway, I boil the water.

A final note: The chemical methods (drops, Polar Pure, tablets, MiOX) leave a residual in the water that protects it to a certain extent in storage. If you use a filter, a Steri-Pen, or boiling, you have to be careful about never putting anything but clean water into your 'clean' containers - because the water can be recontaminated if it comes into contact with a 'dirty' container. (It's usually pretty elementary to have the discipline to approach this problem: for me, the 'dirty' things are my cookpot (which will be sterilized the next time I use it anyway), my wash bucket if I've brought it, and the 'dirty' side of my filter. Every other water container is 'clean' and never allowed contact with 'dirty' water.

[DaTwiztedOne]

thanks for the help.

[Odd Man Out]

There are a lot of threads on the subject here on WB. What is both popular and fairly safe:
...


Nice summary Kevin. I might add a couple things about filters.

Another advantage not mentioned is that they have the ability to improve the taste of water.

Also, your comments about the filter's hose and their weight don't necessarily apply to the gravity and squeeze filter systems.

[Colter]

...
Trusting: At least on the AT, if you're reasonably careful about your choice of water sources, the hazard from contaminated water is overrated. (Even those who claim to have contracted Giardia are much more likely to have got it from unwashed hands, their own or others'.)...

Another Kevin, that was an outstanding overview of treatment methods, thanks!

I respectfully disagree with the above paragraph, however.

There are several scientific papers that have clearly shown the importance of treating water, some specifically studied the A.T.:

"Health care needs of Appalachian Trail Hikers" (http://www.ncbi.nlm.nih.gov/pubmed/8482936) ...Methods to purify water need to be used regularly...

"Medical Risks of Wilderness Hiking" (http://www.ncbi.nlm.nih.gov/pubmed/12681456) In a prospective surveillance study, 334 persons who hiked the Appalachian Trail for at least 7 days (mean [+/- SD] length of hike, 140 +/- 60 days) in 1997 were interviewed. ...Diarrhea is the most common illness limiting long-distance hikers. Hikers should purify water routinely, avoiding using untreated surface water...

"Influence of Hygiene on Gastrointestinal Illness among Wilderness Backpackers" (http://www.ncbi.nlm.nih.gov/pubmed/14769284) Lack of hygiene, specifically handwashing and cleaning of cookware, should be recognized as a significant contributor to wilderness gastrointestinal illness. Hikers should routinely disinfect water and avoid untreated surface water.

These are all papers who studied what ACTUAL A.T. hikers did, and the results. The papers, according to my reading of the numbers, show that water treatment is MORE important than hygiene, but that BOTH are important. Note that the papers don't say "drink smart" they say to treat water ROUTINELY.

The only study that looked at hiker hand contamination (http://www.adirondoc.com/publications/hand_contamination_2012.pdf) of which I'm aware showed their hands were CLEANER leaving the field than when they started their backpacking trip.

[Another Kevin]

Nice summary Kevin. I might add a couple things about filters.

Another advantage not mentioned is that they have the ability to improve the taste of water.

Also, your comments about the filter's hose and their weight don't necessarily apply to the gravity and squeeze filter systems.

Noted, and updated, thanks!

[Another Kevin]

Another Kevin, that was an outstanding overview of treatment methods, thanks!

I respectfully disagree with the above paragraph, however.

There are several scientific papers that have clearly shown the importance of treating water, some specifically studied the A.T.:(...snip...)

These are all papers who studied what ACTUAL A.T. hikers did, and the results. The papers, according to my reading of the numbers, show that water treatment is MORE important than hygiene, but that BOTH are important. Note that the papers don't say "drink smart" they say to treat water ROUTINELY.

The only study that looked at hiker hand contamination (http://www.adirondoc.com/publications/hand_contamination_2012.pdf) of which I'm aware showed their hands were CLEANER leaving the field than when they started their backpacking trip.

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.

[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-PointOne-Squeeze-Pouches/dp/B005EHPVQW/ref=sr_1_1?ie=UTF8&qid=1365874896&sr=8-1&keywords=sawyer+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 (http://cat.inist.fr/?aModele=afficheN&cpsidt=2185085)

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 (http://cat.inist.fr/?aModele=afficheN&cpsidt=2185085)

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. (http://www.elibrary.dep.state.pa.us/dsweb/Get/Document-85277/3800-BK-DEP0524_083011.pdf) 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 (http://www.gihealth.com/html/education/giardia.html)

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. (http://www.elibrary.dep.state.pa.us/dsweb/Get/Document-85277/3800-BK-DEP0524_083011.pdf) 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 (http://www.gihealth.com/html/education/giardia.html)

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 (http://www.rei.com/product/851771/first-need-xle-elite-water-purifier)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."