View Full Version : Another water purification question...
After years of day hiking/car camping, I'm looking to do some backpacking trips & have decided to filter/purify my water. Not really an AT-specific question, but I figure you guys would be well informed:D
Of course, I'll try to pick clean water sources, but I was wondering just how 'bad' a water source can you filter/purify? Think of the worst muddy, stagnant pool of water you've come across, and then throw in some decaying animals/cattle poop? Is it safe to treat?
In an emergency, can you drink that kind of water without filter/purify? Surely it might make you sick, but would it be worse than heat exhaustion? Thanks!
Tennessee Viking
09-16-2007, 01:57
Generally, you do not want to drink untreated water. In emergencies, you definitely want a cool running stream, clear color, no decaying debris in water, and lacks slime or scum on the bottom or rocks. And mountain tops usually have the cleanier of the water. Also waters coming out of deep rock have some reliable safe drinking.
Official or piped water sources have been fairly reliable year round sources. If your doing backcountry stuff, treat all water.
Waters near farms/roads are heavily contaiminated.
A lot of hikers will pack 2 bladders or bottles. One for drinking, and one in process of being treated.
A friend of ours put us on to this trick, to lengthen the life of your filter. Buy a very small lawnmotor gas filter (they are about 3 or 4 inches long). The little filters have two ends that fit perfectly on the tubing of a Katydn/Pur filter hosing. Snip the hosing in two, about half down, on the intake end. Insert the lawn mower filter on either end.
This "pre-filters" a lot of the garbage out of the water before it gets to the main filter system. Has really helped lengthen the life of our filter on trips. My husband generally carries an extra little one, in case we get into some really muddy water and have no other options--which was the case on our last trip b/c of the droughty conditions.
Apologies if this has been a trick posted here before--Gum
Javasanctum
10-31-2007, 19:37
A friend of ours put us on to this trick, to lengthen the life of your filter. Buy a very small lawnmotor gas filter (they are about 3 or 4 inches long). The little filters have two ends that fit perfectly on the tubing of a Katydn/Pur filter hosing. Snip the hosing in two, about half down, on the intake end. Insert the lawn mower filter on either end.
This "pre-filters" a lot of the garbage out of the water before it gets to the main filter system. Has really helped lengthen the life of our filter on trips. My husband generally carries an extra little one, in case we get into some really muddy water and have no other options--which was the case on our last trip b/c of the droughty conditions.
Apologies if this has been a trick posted here before--Gum
Hey that is a clever idea! Thanks!
take-a-knee
10-31-2007, 21:08
mfshop, yes heat exhaustion/dehydration can kill you and drinking putrid water will give you diarhea which will dehydrate and kill you. Pick your poison, or better yet don't allow yourself to be in a position to have to choose between two bad choices. Organisms tend to cling to any organic matter, so the first order of business is to remove this matter, or avoid it in the first place. If you are in a canoe in the middle of a lake, if will most likely be safe to drink the water. Nearer to shore in ankle deep water, it is a different story. The Army uses some tablets called chlor-floc that will work with pond scum, a chemical causes the organic matter to settle out and the rest is safe to drink.
Viruses are way too small to filter, and unless you are downstream of humans these are usually not a problem. Good filters get rid of all bacteria (if they are working properly) and all protozoans like Giardia and Crytosporidium. There is no known treatment for the latter, don't catch it. Iodine based treatments like Polar Pure work great as long as you don't have thyroid issues. Chlorine Dioxide tabs work well. Chlorine bleach, 2 drops per quart of clear cool water will usually suffice.
If this sounds complicated, it is because microbiology and the human body tend to be complicated. I suggest a lot of further study on this matter.
shelterbuilder
10-31-2007, 21:28
Of course, you can always boil your water for at least 5 minutes (a good, rolling boil) to kill whatever's in it. As long as you have fuel of some type (think "wood fire" here), this always works.
Shelterbuilder,
Recently the recommendations have changed. The following quote is from "Wilderness Medicine", Fifth Edition, by Paul S. Auerbach. This was published in 2007:
"The boiling time required is important when fuel is limited. The old recommedation for treating water was to boil for 10 minutes and add 1 minute for every 1000 feet in elevation. However, available data indicates this is not necessary for disinfection. Evidence indicates that enteric pathogens are killed within seconds by boiling water and rapidly at temperatures above 60*C (140* F). In the wilderness, the time required to heat water from 55*C (131* F) to boiling temperature works toward dininfection. Therefore, any water brought to a boil should be adequately disinfected. An extra margine of safety can be added by boiling for 1 minute or by keeping the water covered for several more minutes, which will maintain high temperature without using fuel, or allowing it to cool slowly. Although the boiling point decreases with increasing altitude, this is not significant compared with the time required for thermal death at these temperatures. In recognition of the difference between pasteurizing water for drinking purposes and sterilizing to kill all microbes, including spores, for surgical purposes, many other sources, including WHO, now agree with this recommendation to simply bring water to a boil. Because of scant data for hepatitis A, the Centers for Disease Control and Prevention (CDC) and the EPA still recommend boiling for 1 minute to add a margin of safety. Other sources still suggest 3 minutes of boiling time at high altitude to give a wide margin of safety."
Though long, my reading of this supports what I have been taught in other classes, that simply bringing the water to a boil, is sufficient treatment.
whitefoot_hp
11-01-2007, 13:09
some things to keep in mind:
We rely on less than boiling water to cure germs everday. That is why they reccommed washing your hands with hot water. Soap loosens dirt and stuff from your skin, but hot water actually kills germs.
i have heard the argument that the presence of green algae in a water source indicates that it is relatively safe the drink from, i am guessing the logic being that algae feeds on bacteria. anyone have thoughts on this?
Bootstrap
11-01-2007, 13:12
Viruses are way too small to filter, and unless you are downstream of humans these are usually not a problem.
Or livestock. Some areas of the Southern Balds, for instance, are grazed by cattle to keep them open. For instance, in Bradley Gap, assume you're downstream from cows....
Jonathan
shelterbuilder
11-01-2007, 13:27
Lyle, the changes in boiling times doesn't surprise me, given what I know about pathogen destruction in composting situations, where 40 to 60 degree C temps (over time) are sufficient to render pathogens inert. Except for certain types of organisms that are present near active volcanic vents on the ocean floor (and, I believe, certain parasites that colonize some hot spring locations), most living organisms are not able to withstand such high temps.
So, I guess that we can all drop back our boiling times, unless we're doing field surgery!:D
Ok if you got your water filer of some kind .I find this water disinfectant i got two coming.
http://www.campingsurvival.com/popuwadi.html
Uncle Silly
11-13-2007, 11:16
Though long, my reading of this supports what I have been taught in other classes, that simply bringing the water to a boil, is sufficient treatment.
Hope you're right! When cooking on my stove, I'm more concerned with fuel economy, so my water may not actually reach a full, rolling boil. But around a campfire, I'll just set the pot in the fire and go do something else while I wait for the water to boil. Usually it gets a full 5-10 minutes of boil time, just because I've busied myself with something else for a few minutes.
I feel pretty confident in the safety of that water. All the signs in the backcountry still recommend boiling water for 5 minutes, so anything I've boiled on the campfire has exceeded that standard.
That is why they reccommed washing your hands with hot water. Soap loosens dirt and stuff from your skin, but hot water actually kills germs.
I've heard the soap is just there to loosen things up and make the organisms slide off the skin. (This was presented as an argument against antibiotic soaps, as the antibiotic isn't necessary.) The hot-water-kills-organisms concept I believe, with a caveat: not all organisms die at all temperatures. I don't know about your hot water heater, but mine's set to around 120deg, not the 140deg quoted earlier in this thread. So any organism that survives 120deg won't be killed by the hottest water coming out of my tap.
And frankly, I don't wanna be washing my hands in water that's too hot. Even low-level burns suck. :D
i have heard the argument that the presence of green algae in a water source indicates that it is relatively safe the drink from, i am guessing the logic being that algae feeds on bacteria. anyone have thoughts on this?
I don't buy it, not by that logic. Green algae is green due to chlorophyll -- meaning food is obtained through photosynthesis.
I think I've heard the same argument, but more as a bit of "common sense": the presence of life in the water indicates low levels of inorganic pollutants. Essentially, if stuff is living in it, it's not likely to kill you (right away). (Conversely, if nothing's living in it, there could be something in the water that killed everything.)
A friend of ours put us on to this trick, to lengthen the life of your filter. Buy a very small lawnmotor gas filter (they are about 3 or 4 inches long). The little filters have two ends that fit perfectly on the tubing of a Katydn/Pur filter hosing. Snip the hosing in two, about half down, on the intake end. Insert the lawn mower filter on either end.
This "pre-filters" a lot of the garbage out of the water before it gets to the main filter system. Has really helped lengthen the life of our filter on trips. My husband generally carries an extra little one, in case we get into some really muddy water and have no other options--which was the case on our last trip b/c of the droughty conditions.
Apologies if this has been a trick posted here before--Gum
Thanks. Will try that. Cheaper than Siltstopper filters. Fabric type not metal screen, correct?
desdemona
01-16-2008, 00:30
Not that I ever see any water, but I wonder if some of you have ever heard of this. It is called the Life Straw, and it was designed to be used by people in third world countries. Looks pretty easy, you just sip with it. Supposedly it treats many many nasties.
I think the shipping costs more than the straw, and I don't know if you can buy them from a North American outlet or how the water tastes. I thought that stuff like boullion was a way of hiding the taste of treated water.
http://www.waterstraws.com/
--des
Not that I ever see any water, but I wonder if some of you have ever heard of this. It is called the Life Straw, and it was designed to be used by people in third world countries. Looks pretty easy, you just sip with it. Supposedly it treats many many nasties.
I think the shipping costs more than the straw, and I don't know if you can buy them from a North American outlet or how the water tastes. I thought that stuff like boullion was a way of hiding the taste of treated water.
http://www.waterstraws.com/
--des
My local army / navy store sells these. I always wondered if they worked. I have a Katadyn Hiker filter and a Thermette for boiling water and these fill my need so I never bought one of the straws. If it worked it would be a good idea for a day hike. I would think the volume of water it could filter would be rather limited because of the small size.
desdemona
01-29-2008, 16:22
My local army / navy store sells these. I always wondered if they worked. I have a Katadyn Hiker filter and a Thermette for boiling water and these fill my need so I never bought one of the straws. If it worked it would be a good idea for a day hike. I would think the volume of water it could filter would be rather limited because of the small size.
I looked into this more. The original LifeStraw (or Life strawII) will NOT work on guardia, which I guess is a major concern (I have had what I think was guardia, and believe me it is NOT NOT NOT something you want.). OTOH, something called istraw (I hate this, why does everyone name their products like this) CAN screen out guardia. (iStraw is also triple the cost.)
I'm inclined to think that unless you had a continuous source of water along the way that it isn't too practical. OH well.
--des
troubletown
01-29-2008, 17:53
Anyone ever used the MSR MIOX purifier on a long hike? If so, how did it stand up?
The First Need purifier filters out microorganisms (giardia, crypto, etc.) and kills viruses, at the same time filtering out organic chemicals (fertilizers etc.). This is probably the safest bet for use anywhere, but it's bulky, relatively heavy, and expensive. Also, you can't scrub crud off of the filter element. It's sealed in a plastic container. I've been using it for over 10 years (three or four filter cartridges) for section hikes (including the Long Trail), and haven't gotten sick on the trail or the first week off from water-borne critters.
Here is an interesting article concerning backcountry water treatment. With the amount of web-based information available from the scientific community, I would suggest that you do more research and "filter" out inaccurate information.
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1349767
CDC states that Giardia is moderately chlorine resistant.
http://www.cdc.gov/ncidod/dpd/healthywater/factsheets/giardia.htm
Here is a link to water treatment methods by the CDC. Chemical disinfectant may not kill crypto,.....hmmmm, me needs to rethink my water treatment process.
http://wwwn.cdc.gov/travel/contentWaterTreatment.aspx