Subscribe Contribute Advertise Facebook Twitter Instagram Forums Newsletter

Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking

Drinking untreated backcountry water can make you sick - but choosing your drinking spots intelligently can greatly reduce that risk. Here, a doctor shares the methods that have kept him healthily "sipping the waters" for the past 20 years.

Print Jump to Reader Comments

by Michael von Gortler, MD | 2006-09-20 03:00:00-06


Sipping the Waters: Techniques for Drinking Untreated Backcountry Water - 1
A hot May day in the Indian Peaks Wilderness just to the west of Boulder, Colorado.

June, 2006. My friend Padre is a minister, a cleric from Ohio, and we get together most years for a backpack in the high country. As we load up packs at the trailhead for the Never Summer Mountains in Rocky Mountain National Park, I ask Padre if we dare leave the water filter behind. We’ve decided to use only unfiltered water on this trip, but he says we should carry the filter just in case. So I toss it in my pack. Throughout the trip we enjoy cold and very pure natural waters - with no gut wrenching regrets later - and the filter remains in the pack, unused.

I’ve often felt a nice connection to the natural world that comes from reaching right down into a stream and sipping handfuls of icy water on a hot day. I make it a regular part of my hiking practice to look for good water and drink some on every hike. Over the years I’ve realized that with proper and systematic evaluation of a water source, one can probably obtain clean and pure drinking water by using careful selection criteria. This article describes the methods I use to decide which waters to sip from. I’ve been doing it continuously now for almost twenty years and never once acquired any intestinal illness during that time.

Background - Giardia in the Jarbidge

It’s only been in the last year or two that we’ve taken to sipping natural mountain waters for an entire trip. For me, coming around to this way of handling water has been a very gradual process. The first and only time that I’ve had Giardia was 23 years ago, when I was a young and naïve graduate student. Then, I’d gone on a backpack trip with a friend into the wilds around Jarbidge, Nevada, a remote area in the northeastern part of the state. The night before we entered the wilderness my friend and I had camped next to an idyllic little river. As the evening twilight settled over us, I cooked up a meal and took water from the river at our feet.

The next morning on our way to the trailhead we came around a bend in the road just upstream from our camping spot, and to my wonder a large flock of sheep proceeded to cross the road in a great cloud of dust. A sheepherder smiled at us as the last of the sheep crossed the road. My friend and I continued on to the trailhead and never gave the sheep another thought.

Trouble hit about three days later. Hiking along, my friend began to complain of stomach pains, which grew worse through the afternoon. Then the illness hit full force, and within hours we were both incapacitated. I’ll skip the messy details but the experience, as they say, is one I shall never forget.

After that awful experience of Giardia, I took it for granted that water everywhere in the backcountry has Giardia in it. That seemed to be the advice wherever I checked. For the next several years I never drank untreated water, always boiling or filtering it first before drinking. I assumed and believed all the warnings about Giardia being ever-present.

One day on a mountain hike in hot weather I ran completely out of water. As the day wore on I realized it was going to be a long, thirsty hike back to base camp before I could get any clean water. Eventually thirst drove to me to consider a drink of raw water, and I started scouting for a likely source. I finally drank from a fast-moving streamlet on a steep slope that carried snowmelt down to the valley stream below. The water was icy cold and very clear. At that point I was so thirsty I didn’t really care what happened, but I noticed after a few days that everything was fine.

Enjoying the Taste of Natural Water

I’ve often felt a nice connection to the natural world that comes from reaching right down into a stream and sipping handfuls of icy water on a hot day.

Over the years there were other opportunities to sample pure, untreated mountain water. Sometimes on high alpine slopes, especially on high ridges with melting snowbanks, I’d dip a hand into a rivulet and take a few sips. Then, it was mostly symbolic, as I wanted to have in my mountain wanderings the experience of just drinking water straight from the Earth. An interesting thing happened: I did this half a dozen times and never had any ill effect. So I began to make it a regular part of my hiking practice to look for good water and drink some on every hike. Eventually it occurred to me that with proper and systematic evaluation of a water source, one could probably obtain clean and pure drinking water by using careful selection criteria.

General Principles of Sipping the Waters

Let’s discuss a few general principles of selecting a good water source. I mainly backpack in the high Rockies of Colorado and Wyoming where snowbanks persist on mountain slopes the year round, so much of what follows is best suited to finding good water in an alpine environment. These methods may be substantially less applicable to water at lower elevations and in places where the water is not moving very fast. For example, in the canyon country of the Southwest I am considerably more cautious about the water I choose to sip.

The considerations about water purity break down into two main classes: biological impurities such as bacteria and parasites, and chemical impurities such as metals or toxins. Here in Colorado, the long history of mining in the mountains has created a number or areas where heavy metal pollution is a real concern. In this discussion I will focus mostly on the common biological contaminants such as Giardia and Cryptosporidium. Avoiding toxic impurities that result from mine tailings requires very specific knowledge of the watershed you are traveling in and is beyond the scope of this article. Normally this problem is handled by the Forest Service authorities and warnings are posted at trailheads. For example, the trailhead for the Fourteener mountain of La Plata Peak in central Colorado carries an arsenic warning for the streams that drain some old mining activity.

First Principle: Get water close to its source

How do we go about finding water with a high probability of being uncontaminated by pathogens? The single most important aspect of finding good sipping water is to get close to the source. Usually this means finding a watercourse that is draining a large snowbank high on a steep slope. While hiking along I scout the slopes above, looking for likely snowbanks that are perched in large talus slopes. These areas are typically the least visited by wandering elk or deer. Often the water coming off these snowbanks courses under the rocks for some distance and this lessens the chance of animal contact with it.

Sipping the Waters: Techniques for Drinking Untreated Backcountry Water - 2
Alpine snowmelt in the Indian Peaks Wilderness.

Second Principle: Make sure the water is cold

Test the water with your hand to see if it is quite cold. Extremely cold water barely above freezing means it has not traveled far from its icy source. Cold water does not make it harder for organisms to survive, but it means that the water has had less chance to come into contact with animals that deposit the organisms.

Third Principle: Look for fast-moving water

Standing or slow-moving water has more opportunities to acquire pathogens from the animal population. In general, look for swiftly moving water, preferably from a small source coming straight down a slope. These streamlets very often drain a melting snowbank during the warmer months. In general, I prefer to avoid sipping the water from any stream wider than four or five feet, unless I know with certainty that it comes from clean water upstream. Some of the rivers I frequent in Colorado are high enough and swift enough to drink from. I am more confident in drinking from these larger streams after I’ve successfully done it several years in a row, and I now have a large inventory of waters around the state that I consider clean and drinkable.

Sipping the Waters: Techniques for Drinking Untreated Backcountry Water - 3
Spring runoff in the Indian Peaks Wilderness. Fast-moving water has less opportunity to acquire pathogens from the animal population. Look for water from a small source that is nearby to further improve quality.

Fourth Principle: Take water that is naturally filtered

I often drink water that is flowing down a forest slope that has lots of vegetation. Here the trick is to seek water that is moving fast and is very cold. I look for a streamlet that has very thick brush growing either side of it, meaning that animals have less access to the water. I have come to believe that lots of moss growing on the rocks in the streamlet is a good sign. It seems to correlate with a high degree of filtration as the moss acts like a kind of sponge, filtering out minerals, dirt, and small bits of debris.

Sometimes I find that good water comes from seeps. A seep is a narrow space in a rock wall that permits a slow movement of water out to its surface. Often you can find a good flat wall of rock with hanging moss gardens and nice clean water seeping from a crack in the rock. This water typically is being filtered through layers of rock and sand above the seep. Just be sure to survey the slope above the seep to make sure there are no obvious elk wallows. Some of the best tasting and cleanest appearing water I’ve found in Canyon Country comes from seeps. Here, the water is being filtered through hundreds or even thousands of feet of sandstone and is likely extremely pure.

Sipping the Waters: Techniques for Drinking Untreated Backcountry Water - 4
Seeps from rocks will likely have water that has been filtering down for years if not much longer.

Fifth Principle: Avoid large mammals

Once in a while my water-sipping strategies backfire, sometimes in a funny way. Once after climbing a high peak in Rocky Mountain National Park I was descending a talus slope in a scantly used drainage. Walking along the tundra I found a likely looking streamlet with the all the requisite qualities. I walked along for a while, looking for elk sign as elk are numerous in this Park. After scouting for a quarter mile and seeing no sign of elk, I bent down and slaked my considerable thirst with the icy cold water. I resumed the march downhill and came around a bend to see four of the largest and most magnificent bull elk I’d ever seen. Each one had an enormous trophy rack of points - they were quite a gang of stately bulls. They were grazing five feet away from the stream I’d just drunk from! I waited nervously for a few days to become sick with Giardia, but luckily nothing ever happened.


Another important consideration is our friend the beaver. Colorado and Wyoming have large beaver populations, and one needs to be on the lookout for them. Sometimes I’ve followed a stream that I considered a good candidate for sipping, only to find a beaver lodge a ways upstream. I’ve sometimes come across many beaver dams in a single creek, spread out over a mile or more. In these areas the stream water should be avoided.


The presence of livestock in areas visited by backpackers can be a problem. This is a thorny political issue but also an ecological and health issue, as cattle may spread pathogens such as Giardia. Unlike elk and deer which wander over very large distances, cattle are often confined to a single watershed and may contribute greatly to fouling of waters. The best approach here is to be aware of any livestock operations in the areas one is visiting. I rarely sip any waters in these areas unless I can clearly see the entire watercourse from its direct source in a snowbank.

Closing Comments

The methods outlined here will help you to survey an area and decide whether drinking natural waters is prudent. Besides offering an option on long hikes when you may not have a filter along, sipping natural waters provides certain spiritual satisfactions and improves the wilderness experience. I feel a lot closer to the natural world when I can move around the mountains and partake of her natural offerings.

Although there will always be some element of risk in sipping natural waters in the wilderness, clearly this risk has been overstated for many years. Some readers may feel that the strategies presented in this article are unreliable or unduly risky, but they have served me well for nearly twenty years. During that time I’ve refined my methods for assessing water quality and have never once gotten ill from sipping water this way. (Of course, keep in mind that despite my precautions and calculations, a healthy immune system and a bit of luck surely play a part in my success too.) For me as a woodsman and mountaineer, being able to eat native wild plants and sip wild natural water is an important part of my life activities. With some intelligent study and thoughtful testing, many people will be able to enjoy the satisfaction of sipping natural waters. Good luck!

About the Author

Sipping the Waters: Techniques for Drinking Untreated Backcountry Water - 5
The author atop Fremont Peak in the Wind River Range, the second highest point in Wyoming.

Mike von Gortler is a middle-aged but active guy who lives in Boulder, Colorado where he is close to vast expanses of backcountry. He's been practicing as an Emergency Physician for the past 18 years. The pursuit of wild chanterelles and other edible mountain plants keeps him moving through the uplands while keeping an eye out for the wildlife and wildflowers. Several times a year he can be found atop a Fourteener with his teenage daughter or some friends.


"Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking," by Michael von Gortler, MD. (ISSN 1537-0364)., 2006-09-20 03:00:00-06.


Reader Comments

You must login to post comments.

New Visitors: Create a new account
Remember my login info.

Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking
Display Avatars
Sort By:
Cat Jasins
(CatJasins) - MLife
Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 09/20/2006 03:44:31 MDT Print View

Companion forum thread to:

Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking

bric brak
(mintaka) - F
sipping the waters on 09/20/2006 05:29:06 MDT Print View

I have found that my friends who have gotten sick in the past were able to drink unfiltered water on current hikes without suffering new symptons.

Edward Ripley-Duggan
(edwardripleyduggan) - F
Backcountry water on 09/20/2006 07:43:18 MDT Print View

Thanks for you excellent article. I hike largely in the Catskills of NY State, where I live (along with the Dacks, and occasionally the Whites of NH). I drink a great deal of untreated water, but I generally follow the source selection rules that you mention, which I've arrived at independently.

I am interested in the comment by the previous poster, because I have heard similar things. To the best of my knowledge I've never had Giardia (and I think I would know)! I have heard that many AT hikers appear to become immune after a couple of bouts. This makes sense, as large populations in the third world drink Giardia-laden water and are also apparently free from its effects, for that infection at least.

Of course, someone who has had the illness is likely to become a carrier, which makes careful disposal of faecal matter paramount.


David Olsen

Locale: Steptoe Butte
Re: Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 09/20/2006 09:19:33 MDT Print View

After reading the authors experience with sheep in the Jarbidge, I would add the old cowboy rule-

"After you get a drink, never ride upstream!"

Mike Clelland
(mikeclelland) - MLife

Locale: The Tetons (via Idaho)
Sipping the Waters on 09/20/2006 09:41:44 MDT Print View

I work in the backcountry, in the North Cascades, for a month at a time. And I almost NEVER treat the water.

I have talked to the rangers there (North Cascades National Park) and they all agree that the water in surface streams is very clean. Lots of snow, lots of rain, lots of flora (as filter), minimal wildlife, steep terrain so little "standing" water.

And - They do NOT get reports of giardia. I found all of this super reassuring.

This is NOT the case in an area like Yellowstone, and I factor that in to my decision making.

The article didn't shy away from personal judgment in a variety of situations. Thanks for treating me like a grown up!

The question I've had is how do you TEACH the judgment to drink untreated water? This article is a good resource.

There are so many products for purifying backcountry water. Yes, these are important (and required) in SOME situations. But, I worry that we are separating ourselves from the natural world. We are the first generation on the planet to ever really concern ourselves with this issue. What could be more natural than drinking when we are thirsty?

What have we lost?

Miguel Arboleda
(butuki) - MLife

Locale: Kanto Plain, Japan
Re: Sipping the Waters on 09/20/2006 10:02:18 MDT Print View

The vast majority of people in the world never treat their water. In some places people get sick, but in most cases people are fine. Part of the problem, I think, is that people have become so protected from the natural world that their bodies no longer develop the immunological protection that would normally form from close interaction with the physical world. Children who never play outdoors don't develop the antibodies to protect them against the most common germs that earlier generations never had a problem with.

No one I know treats their water here in Japan when walking the hills and mountains. I've only gotten sick once, 34 years ago, when I swam in a lake in northern Japan in an area where many deer and brown bear also used the lake. I know of no one else who has gotten sick from drinking wild water here.

Really, these days people are becoming afraid of their own shadows. There should be prudence, of course, but not paranoia.

Tom Clark
(TomClark) - MLife

Locale: East Coast
Giardia in your system on 09/20/2006 10:41:50 MDT Print View

Warren Doyle (founder of ALDHA ) has commented that he had Giardia in his system for many years, but lost it after some period of not sipping the waters. He said that he was very happy to reintroduce it to his body, although the process itself was unpleasant.

A friend of mine from India got sick when he returned home after a few years in the US. Now when he goes home, he doesn't drink the water either.

kevin davidson
(kdesign) - F

Locale: Mythical State of Jefferson
re. sipping the waters in the 3rd world on 09/20/2006 11:22:30 MDT Print View

We are pretty lucky living in the developed world (N.America, Japan, Europe, Australia) when it comes to relatively safe water supplies BUT 5 million people a year in the rest of the world die from waterborne diseases from untreated water and 10s of millions contract waterborne diseases each year.
Furhermore, there are disease organisms in water supplies that the local populations never develop immunities to.

Otherwise, i agree that fears of drinking "wild water" are often overstated. I have a similar approach to Mike when it comes to water in the N. Cascades and there are swaths of the Sierra where I feel I can safely drink untreated water, as well.

Edited by kdesign on 09/20/2006 11:24:42 MDT.

Tom Clark
(TomClark) - MLife

Locale: East Coast
Contradiction? on 09/20/2006 11:23:22 MDT Print View

Can someone clarify what seems to be a contradiction between the two recent articles when discussing tips to find safe water. Tips (A) and (2-5) in the following lists don't completely mesh in my mind. Which is safer (all else being the same) cold, fast-moving water or warmer, still lake water? I understand UV helping to kill microbes in a lake, but the idea of multiple water, animal, and insect sources dumping microbes into a warmer lake that could encourage growth doesn't seem like an advantage.

I would choose getting water from the feeder stream rather than the pond/lake.

From "Backcountry Water Quality":
"Currently working with Lake Tahoe expert and UC Davis professor Charles Goldman, Derlet has several other water quality findings in the Sierra that he also hopes to research:

(A) Lakes are typically ‘cleaner’ than creeks, possibly because the ultraviolet rays of sunlight work better at killing off bacteria in calm waters of a lake than in the tumbling flows of a stream.
(B) Algae growth in the backcountry appears to be getting worse.
Bacteria readings appear higher at the beginning of spring runoff rather than later in the summer when water levels are lower and water qualities thought to be poorer.
(C) Valley air pollution could be contributing to water quality problems in the Sierra Nevada."

From "Sipping the Waters":
"Doc’s Rules for Sipping the Waters
(1) Study the watershed you are in. Know what is there.
(2) Look for water near to its source.
Try to take water from the sideslope streamlets.
(3) Avoid water from the main valley stream.
(4) Look for icy cold water.
(5) Look for fast-moving water.
(6) Study the area for the presence of large animals.
(7) Ascertain whether numbers of elk have recently been in the area.
(8) Avoid waters near beaver ponds or cattle grazing.
(9) When possible drink a test amount before drinking liberally a few days later from those same waters."

Also, when I look at all of the marmot *BEEP* piled up on rocks in the Sierra, I have to wonder how much of that gets washed into streams during snow melt and rain runoff.

Are certain animals considered more harmful (marmots, deer, horses, dogs, humans) given equal volume of *BEEP*? Although humans are encouraged/required to bury their scat, the other animals certainly don't.

Miguel Arboleda
(butuki) - MLife

Locale: Kanto Plain, Japan
Re: sipping the waters in the 3rd world on 09/20/2006 12:57:09 MDT Print View

Kevin, of course you are correct about problems with water supplies in the poorer, populated places of the world. I've traveled all over Asia and seen it with my own eyes (spent some time on Smokey Mountain in the Philippines and journeyed along a few of the absolutely filthy rivers), but we are talking about places for back country walking, are we not? After all people are talking here about water bourne problems in the States mainly, no? A "developed" country. Even in the poor countries the back country is usually clean just like in the "developed" countries, and less prone to the big water bourne dieases. I would never condone drinking untreated wild water in populated places or where it tends to be hot. I mean you can't even eat raw vegetables in such places unless your body is acclimated.

John Davis
(JNDavis) - F

Locale: Isle of Man
Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 09/20/2006 13:23:00 MDT Print View

In the Cairngorms, rivers like the Tarf and Eidart carry peat-stained water which tastes delicious. In the villages, down in the glens, the water is chlorinated and tastes foul. It's a strong argument for getting far into the hills but makes me wonder if we are doing something wrong down in civilisation.

By the way, I lived for two years in the Philippines but only caught amoebic dysentery near the end when I let my guard down at a dinner party. Perhaps chlorinated water isn't so bad after all.

Edited by JNDavis on 09/20/2006 13:25:52 MDT.

David Bonn
(david_bonn) - F

Locale: North Cascades
Re: Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 09/20/2006 14:52:08 MDT Print View

Great article.

As another denizen of the North Cascades, I'll second Mr. Clelland's comments about drinking the water here. And since cattle and sheep aren't being ran in the east-slope wildernesses (Pasayten and Lake-Chelan Sawtooth) anymore I'm less worried about waterborne pathogens there too.

I'd add another consideration: the presence of other hikers. If you are in a popular hiking area and (for whatever policy reason) there aren't privies or toilets, I'd trust the water in that area considerably less. I'd also be a little worried about how those toilets are sited, but usually that is done very well. My observation is that people will go far, far out of their way to use privies.

On a similar point, I'm also real fussy about sharing food that might have been handled by another hiker, and am fussy about keeping my hands clean before and during a meal too. It isn't that I don't know where someone's hands have been. I do know. What I don't know is if they know how to wash their hands.

Victor Karpenko
(Viktor) - MLife

Locale: Northern California
Did he really have Giardia? on 09/21/2006 00:13:16 MDT Print View

“Trouble hit about three days later. Hiking along, my friend began to complain of stomach pains, which grew worse through the afternoon. Then the illness hit full force, and within hours we were both incapacitated.”

According to NOLS Wilderness First Aid, the incubation period fro ingestion to onset of infection is one to three weeks.

The CDC states, “Symptoms of giardiasis normally begin 1 to 2 weeks (average 7 days) after becoming infected.”

John S.
(jshann) - F
Risk versus benefit on 09/21/2006 08:03:01 MDT Print View

A few points of debate below:

The good doctors principles for finding safe drinking water seem largely impractical for those persons visiting an area that do not have the time or resources to go to the extent of the rules given. Also, for the most part, the doc has IMMEDIATE access to FREE health care in the event he becomes ill..upon return when many of the cases become symptomatic. Nobody else has those combined benefits. Appropriate water treatment is the best insurance for the majority. Chlorine dioxide tablets are my staple everywhere and always.

John Shannon, M.D.

Edited by jshann on 09/21/2006 11:38:37 MDT.

Sunny Waller
(dancer) - M

Locale: Southeast USA
Re: Risk versus benefit on 09/21/2006 08:30:46 MDT Print View

Yes girdia does show up later but thats not the only way you can get sick from bad water. Some stuff hits fast and hard (or should I say loose :)
How many times have you quickly gotten sick from something you ate or drank and went running for the bathroom? The woods is a terrible place to be when your system goes south. Several of us got sick in the backcountry one fourth of july..we all drove seperatly and met out on the trail...we did not share any food-not even trail mix..It was a very difficult hike back out to the cars. Fortunatly there were lots of bushes. Later several of us got very ill and were treated for Girdia. We discovered that we had all drank a batch of untreated water-we had a new person who did not know to use the filter. We were camped at a VERY popular campsite. To this day I carry immodium and I treat and collect my own water. Once was enough for me.

NOTE: I live and hike in the Southeast..that does make a difference..smaller spaces..lots more bears..ect ect ect...not a bad a place as Dr J writes about in his article..but it is different :)

Edited by dancer on 09/21/2006 08:38:32 MDT.

Roger Caffin
(rcaffin) - BPL Staff - MLife

Locale: Wollemi & Kosciusko NPs, Europe
Did he really have Giardia? on 09/22/2006 05:02:25 MDT Print View

Victor wrote:
> “Trouble hit about three days later. Hiking along, my friend began to complain of stomach pains, which grew worse through the afternoon. Then the illness hit full force, and within hours we were both incapacitated.”

> According to NOLS Wilderness First Aid, the incubation period fro ingestion to onset of infection is one to three weeks.

> The CDC states, “Symptoms of giardiasis normally begin 1 to 2 weeks (average 7 days) after becoming infected.”

I have to agree with Victor. I doubt it was Giardia. My reasons:
* My understanding is that the form of Giardia which sheep can carry is not the G lamblia which affects humans.
* It takes time for the Giardia protozoa to multiply up in your gut to the level where they can be detected. The normal incubation period is usually 10 days, not four.
* Giardia lamblia does not suddenly cause you to become incapacitated in the time quoted, of less than one day. You may rumble a bit, but for TWO people to be simultaneously affected to that extreme - nope.
* However, something like a rotavirus will affect two people exactly like this, about 24 hours after drinking contaminated water. I KNOW! There are other vectors possible, but my money is on this one.


Mary Simpson
(maryphyl) - F
Untreated Water on 09/22/2006 12:16:08 MDT Print View

I hike almost exclusively in the Grand Canyon or on the Mogollon Rim in Northern Arizona. I have never treated any of my water and I have never been sick in 30 years of hiking here. A local doctor made this recommendation--the bugs you do not want are mostly on the bottom or on the surface of the water. I clear off the surface just before dunking a bottle and make sure I don't get any from the top or the bottom. I try to be aware of the source and have chosen to boil water a few times when I felt it was questionable.

Bruce Tolley

Locale: San Francisco Bay Area
Never been sick on 09/23/2006 14:55:30 MDT Print View

This thread seems to have overlooked some of the science involved: namely that not all those exposed get infected and not all those infected show symptoms. But those infected do become vectors.

Just because someone has never been sick does not mean 1) that they have not been exposed and 2) that they have not been infected.

Bottom line: different folks have different risk profiles. If you hike in backcountry frequented by other humans, the risk of water borne disease is not zero. Solo hikers of course make the decision for themselves and this article offers sound advice on how to reduce the risk of exposure. Those of us who are leading groups, need to consider the risk to the whole group especially the young and those with possibly compromised immune systems. And there are other organisms in water like crypto that can do more harm than giardia.

Derek Douville
(avaktar) - F
Light filtration on 10/17/2006 02:14:57 MDT Print View

Cryptosporidium gives me the creeps, and in undeveloped lands like South America or China, even viruses can be floating around. I prefer to be safe and enjoy my vacation, rather than spend it building tolerance to a bacteria.

In developed countries (such as the US or Canada), when there is plenty of time to investigate a water source according to all of the mentioned techniques, the water may very well be safe. But these days with innovations such as the SteriPen (90 seconds/L) or the MIOX purification system (30 mins for 95% and 4 hours for 99.9%), water can be treated without disrupting the taste, and with very little effort.

I was recently hiking in Sunol Wilderness, California, at 1200+ feet, but the normal water channels are quite dry at this time of year (mid-October). The only water available was still water, and the cattle manure was plentiful and very close to all water sources. In this situation, a proper filter and purification system is essential, and the park rangers require this gear for backpackers who intend on camping.

I understand the desire and pleasure to take from the natural land, but this advice should be offset by common sense and preparedness - have some form of purification available for emergencies.

Frank Ramos
(frprovis) - F
backcountry water dangers on 11/09/2007 22:01:16 MST Print View

Well, well, well. Just as I predicted last year, helminthes are starting to become a problem in Europe. Read this frightening news:

Foxes in Munich causing echinococcosis

This could happen in the US too, since these echinococcosis worms are also present in North America (wolves in the arctic) and can be carried by any canine, including foxes, coyotes, wolves and dogs.

I notice that McNett has introduced the Aquamira Frontier Pro Filter, which appears to be exactly what I was looking for last year. Namely, something that filters worms and other large parasites but isn't so fine as to clog easily. I'll be using this on future trips.

Incidentally, there is no reason to get too worried about cow manure near the water. Cow manure is loaded with bacteria but adult humans with a strong immune system are normally capable of shaking off most bacteria infections with ease (assuming you get enough sleep and food and aren't otherwise stressed out). I routinely drink from streams with cow and horse nearby and never get sick. Typhoid and hep A are pretty serious bacterial infections, but these don't exist in the North America or European backcountry.

Viruses are species specific, so they are only a problem if there are humans around, and the humans in North America and Europe are not carrying dangerous viruses (such as polio). The viruses they are carrying (Rotaviruses and Norwalk) are easily shaken off by a healthy adult.

Giardia and crypto are also easily shaken off by a healthy adult. Amoebic dysentery and various other Third World parasites are a serious problem, but these don't exist in North America or Europe backcountry.

Mike Clelland
(mikeclelland) - MLife

Locale: The Tetons (via Idaho)
Selecting Untreated Backcountry Water for Drinking on 08/04/2009 22:14:54 MDT Print View

I love this article!

Michael Swanson
(wutzmyname) - F

Locale: Northern California
Re: Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 08/05/2009 17:22:44 MDT Print View

Great article. It certainly proved invaluable during my hike through Desolation Wilderness in Tahoe last week.


Nate Meinzer
(Rezniem) - F

Locale: San Francisco
Wait two weeks on 08/05/2009 18:08:46 MDT Print View

Then you'll know for sure....

Glenn Douglas
My experience in South America. on 04/16/2010 20:30:29 MDT Print View

I have been hiking in South America for about the last year and a half. I have drank all water untreated from Santiago south to Ushuaia and never had any problems on either side of the Andes.

However in Peru and Bolivia I did. I used a katadyn mini water filter and had problems for the first three treks in the following areas.
Bolivia - Cordillera Real - Choro trek and Sorata Area.
Peru - Ausungate Circuit.

I then switched to using Chlorine tablets and did not use the water filter for treating all water including cooking water and had no further problems in either country.

I believe the problems come from livestock (llamas) grazing even at high altitudes in Peru and Bolivia. Its hard to get closer to the source than the animals do.

I will use chlorine tablets in Peru and Bolivia in future.

Ted E
(Mtn_nut) - MLife

Locale: Morrison, CO
Re: Re: Sipping the Waters: Techniques for Selecting Untreated Backcountry Water for Drinking on 04/17/2010 14:01:39 MDT Print View

I personally think all water should be pre-filtered at least with something similar to a coffee filter. i've hiked into the indian peaks wilderness, and while i think the water would probably safe to drink on the west side of the divide, pre-filtering it keeps bugs and other stuff out of the water.

Also, now with things like the steripen, all my water will be sterilized with UV light, and then i can still get fresh tasting water without having to take a chance of getting very sick in a remote place...

Edited by Mtn_nut on 04/17/2010 14:02:52 MDT.

obx hiker
(obxcola) - MLife

Locale: Outer Banks of North Carolina
frontier pro on 04/17/2010 14:44:31 MDT Print View

Hi Frank,

Per your post: "I notice that McNett has introduced the Aquamira Frontier Pro Filter, which appears to be exactly what I was looking for last year. Namely, something that filters worms and other large parasites but isn't so fine as to clog easily. I'll be using this on future trips."

I have had positive and negative experiences with the frontier pro; recently having it clog up from suspended solids from what could fairly be considered fairly pristine sources within 200 verticle feet of the uppermost ridge. Maybe I was getting suspended leaf mold that would be less of a problem once things greened up but the water appeared to be VERY clear and was coming out of the ground within sight. (this was late March, southern appalachians)I'd pre-fiter with a bandanna or something and be careful! If the little cotton type pre-filter disk clogs you'd better have a back-up or you to will be drinking al fresco sans filtro or whatever.

I'm in the process of making a home-made amigo pro

Buck Nelson
(Colter) - MLife

Locale: Alaska
Anecdotal or scientific? on 09/27/2014 12:20:00 MDT Print View

Let me lead off by saying that water treatment is a personal choice.

That said, the author's rules are not backed with good data. The author suggests looking for cold water, while other authors point out that giardia cysts survive longer in cold water, making it more risky. The author suggests using fast moving water, some have suggested lakes are safer as giardia cysts tend to sink in calm water. The author suggests avoiding main streams, other authors say main streams are safer because "dilution is the solution." The point is, these are theories without solid data to back them up.

It is human nature to believe in our own experience. In threads like this there are usually people who've gotten giardia after drinking backcountry water. I'm one of them. Will someone's experience match mine, or someone who has never gotten sick? There's no way of knowing.

The EPA says Cysts have been found all months of the year in surface waters from the Arctic to the tropics in even the most pristine of surface waters. Another quote from that paper Hibler (1988) found Giardia cysts in 19% of springs. Look at that paper and do a search for "pristine" and see how often giardia is found in even pristine waters.

Some people can build some immunity over time to various waterborne diseases, but there are many strains of giardia. I've had giardia three times and it's easy to find tales from other hikers who have been stricken multiple times over many years, just as it's easy to find hikers who rarely or never treat and have never gotten sick.

The incubation period of giardia is usually 3-25 days, but can be as little as 1 day. The Dr's reported onset was on the 4th day after drinking the suspect water.

Sheep DO sometimes carry a strain of giardia that can infect humans, as can many other species of animals.

"Giardia and crypto are also easily shaken off by a healthy adult." Sometimes. Sometimes not. Several backpackers appear weekly at Centinela Mammoth Hospital in Mammoth Lakes sick enough with giardiasis to need urgent care

"Incidentally, there is no reason to get too worried about cow manure near the water." ...animal manure can carry many pathogens ranging from Giardia to Salmonella to E. coli. Here's a fact I recently uncovered: Giardia-infected cattle excrete nearly 100 million Giardia cysts per day Dr Robert Derlet.

Unfortunately while researching this I was saddened to learn that the author of this article, along with his daughter, lost their lives in the Colorado mountains in 2011.

Edited by Colter on 09/27/2014 12:23:43 MDT.