new water filter claims to filter out virus

Has anyone heard of this?

http://www.gofastandlight.com/Simple-Cam...ctinfo/W-R-DIY/

Sawyer has, or at least used to have, a filter that was supposedly fine enough to filter most viruses. Problem is, if a filter is fine enough to filter viruses, it is very slow and very prone to clogging.

If I were worried about viruses (such as a river that drains inhabited areas, or in "third world" countries), I'd take chlorine dioxide tablets and use those, either alone or in conjunction with a filter. Used in conjunction with a filter, you don't have such a long waiting period, because the filter gets the protozoa (like giardia), while the chlorine dioxide zaps the viruses and smaller bacteria in about 20 minutes. (It's the protozoan cysts that take several hours to kill.)

Before relying on this gadget, I'd want to see independent technical third party reviews, not from manufacturers or retailers, that show both lab test results with polluted water (does it really get all the viruses?) and real world use (does the filter keep working or does it clog all the time?)

And Gore Tex (and others) claim to be waterproof AND breathable.

Roger Caffin at BPL did a review of Rapid Pure in Sept. 2014.

You must be a member to read it, though.

https://backpackinglight.com/rapid-pure-filters-caffin/

Sawyer still has the Point ZeroTWO filter, but does not claim that it removes viruses. The specs page just says protozoa and bacteria. The RapidPure filters appear not to be simply particulate filters, but seem to incorporate some kind of electrochemical treatment. The RapidPure particulate claim is 0.2 microns, same as most everybody else. I don't generally see the need of going to greater lengths to purify backcountry water, as long as the source appears to be relatively clean. I think that the protozoans are the backcountry traveler's biggest concern, other than chemically contaminated water.

I was looking at some of the water treatment chemicals that I have and I noticed a statement on one of the chlorine dioxide (might have been Potable Aqua)packages, that the 4 hour time was for the "Chlorine Dioxide to develop". This may mean that the chemical in the tablets does not immediately react and produce chlorine dioxide. I'm not that familiar with this process, but I know that the contact time in most water treatment plants is much less than 4 hours, usually less than 30 minutes. Of course, the residence time of the water in the system before use is usually considerably longer.

I think that cross contamination and personal hygiene are far more important to the backcountry traveler then absolute purity.

One of the advantages to the Steripen is that it kills viruses, and without relying on a filter which can get plugged or run slow. That is one of the reasons I like it, though I don't think the virus factor matters much for typical north american backpacking trips. You don't find hepatitis living in mountain streams in US national parks. It is pretty useful for Third World traveling, though, both in the backcountry and in cities.
One additional advantage of Steripens, too, is the additional nutritional value you get in your water. Filters remove all the little pollywogs and eggs and larvae from the water, which are such a good source of protein.

Seriously, though, the Steripen doesn't work well in cloudy water. Waters with tannin from decayed vegetable matter will foul up the Steripen even if filtered first.

I had bookmarked a bunch of links to Dept.of Defense websites on both water purifiation and bug repellent (in both cases, the protocol used to protect our troops), but they have all gone dead. If anyone wants to look them up, feel free! That's where my info came from, but unfortunately I can no longer document it. Grrrr!

The steripen doesnt actually kill anything. Its sterilizes viruses and bacteria so they cant multiply. They are still alive. I play it pretty safe. I filter the water and then use iodine / ascorbic acid. Then flavor the water.

That should be the take-away on all threads about water purification.

I don't have time tonight, but I guess it's time for another of my annual rants about the dangers of using iodine!

I was thinking the same thing (uh oh, OM's gonna school em )



Yep. When you look into it viruses in water here are not a huge problem, and even less of one when you get into a pretty much pristine wilderness area. If you have a good source those little water bugs are good for you. They help build and maintain your immune system, and iodine and chlorine do just the opposite of that. I'd rather boil water than use those.

"What is a good source?" is a different subject, but it's certainly worth learning about if you don't know.

It seems to me that all the "data" on water purification is hearsay. How do you know if it works? You do not get sick with purified water; no double-blind test- who knows if you would not get sick WITHOUT purifying? Contamination is mostly a matter of concentration of bugs. One or two will not harm people with normal immune systems. One hundred may. Some people are able to drink vast quantities of bugs and not get sick at all.

EPA water quality standards for drinking water are based on protection of the MOST vulnerable population. Most people can tolerate far more contaminants with no ill effect.

And if you do get sick, how do you know if it is from your hands or the water?

Last thought- this is another example of our "too clean" society. Like they say - eat dirt when you are a baby and you will have a stronger immune system.

But be smart. I do not take water from a stream that sits next to an outhouse! Or flows through a field of cow pies. Or is in a pit at an abandoned mine site. There definitely are times and places for water purification, but I think we have gone over the edge of paranoia. The Forest Service simply says "treat all water" so they do not get sued. It is mostly about legal liability.

And a second thought- has any agency done a test to compare the probability of harm from "bad water" vs the long term effect of daily use of chemical water purification products? Maybe the cure is worse than the problem.

And for filtering, unless you sterilize your hands and the bottle before filtering, you can introduce germs. Filters that are not properly cleaned can also cause contamination.

Yup, disinfection byproducts in drinking water are monitored and regulated. A CDC primer on DBPs and current regulations can be found here.

Simple chlorination of water with lots of organic compounds creates trihalomethanes, which are regulated under the SDWA. Some cities switch to chloramine when they experience high THM levels from chlorine. Chlorine dioxide treatment can generate chlorites, discussed here.

Cheers,

Here's the definitive writeup on water treatment methods:
Water Disinfection for Travelers
Note that they all have their issues.

Thanks, Rick, for the info on byproducts. We keep being told that chlorine dioxide is harmless (although chlorine bleach we know is not). All I know is, the ClO2-treated water does have a chlorine taste. I take it along only as backup in case my filter gives out. The last time that happened, I forgot the ClO2 tablets, so I spent three days boiling (only had a small kettle) instead of fishing.

Iodine writeup will be in a separate thread, in the Backcountry Health and Safety forum, which is probably where this thread belongs.

A lot of good comments here. And yes, I did notice that the steripen doesn't actually kill things, right before I drank a bottle of sterilized water with little things swimming around in it. As a vegetarian, I have to say I felt a pang of guilt for swallowing them all live, but my water source was severely limited to nothing else by drought. Yes, a filter would've been better!
It has been interesting to talk to backcountry rangers and trail workers in the Sierra the last few years who never treat their water, even if that isn't officially expressed Agency Policy. So perhaps it is true that the reason our purification methods always seem to work is that our water sources actually have nothing in them to infect us: no objective test there.
Then again, maybe we don't get sick because we have such healthy gut floras and immune systems from backpacking and sleeping, cooking, and sitting in the dirt everyday! Truth is, I kind of believe that argument to have some validity!

OM- that article states that the EPA simply uses the tests that are done by the manufacturer of the treatment devise/method - they do not do independent testing.

What the article does imply is that there is no need to treat cook water if it is brought to a full boil.

And I do think that 99% of the "success" of treatment is due to no problems to begin with. At least, in the high mountain areas where I backpack. If you think about it, a tumbling mountain stream is aerated, somewhat filtered and subject to high intensity UV, all "treatment" methods.

Things may be different in lower altitude more agricultural settings or in campgrounds.

The part of the CDC article about solar disinfection was interesting. I had heard something about that before but not in such detail. I use a nalgene water bag a lot of the time, which is clear and can be arranged to get a lot of sun exposure. Seems like it could be left in the sun all day, sitting on aluminum foil and be pretty well sterilized. (It also implies to me that I would be best to store my emergency earthquake water at home where it would be exposed to sun regularly, in order to keep it drinkable for longer). It also helps explain how intense high altitude sunlight shining on shallow babbling mountain brooks can make water safe to drink.
I also find it interesting that the article says that you can actually sterilize water by heating it to lower temps than boiling, though boiling is more easy to determine than say 160 degrees. Of course I'm going to try to boil it, but in an emergency of low fuel, at least one has other options.

I certainly don't treat cooking water! What a waste!

My concern here in the Cascades is primarily the many lakes whose inlets and outlets dry up by midsummer, so there's no circulation. We have a number of such areas, nearly all of which are named or nicknamed "mosquito," which means most of us visit only in late summer or early fall during the "no circulation" season. People swim in those (water is a bit warmer)! The other concern is rivers that drain inhabited areas (= septic fields and sewage plants and maybe a few old-fashioned privies) and/or drain agricultural areas (agricultural chemicals which can't be filtered out). I stay away from the last!

That's true for all the things EPA regulates--the manufacturers are responsible for testing and submit their results. My late ex-husband used to do field testing for a pesticide company. Lots and lots of paperwork!

The fact that someone has taken a lot of trips with no water treatment and never been sick is not proof of anything. The person may be immune (I suspect I am, having drunk from mountain streams since childhood) or lucky. Anecdotes are not data!

I have, though, found dead animals in the water upstream of where I was getting water, which has made me more cautious. I also know of one high-altitude spring in the Glacier Peak Wilderness that was the site of popular hunting camps for many many years before the Forest Service put in wilderness toilets. I suspect the ground water there may be polluted, since I know several people who got sick from it (that being the only place they didn't treat their water, and knowing that they're careful about hygiene). Again, that's anecdotes, though. We are dependent on the sanitary practices--or lack of them--of those who have come before us.

Norovirus has come to be a big concern, although the outbreaks on the AT seem to be spread via careless hygiene, rather than the water.

Actually, leaving water out in the sun may promote algae growth. The algae comes from stuff floating around in the air that gets in the water while you are filling the container. I have a 275 gallon LDPE tote on a trailer that I keep for wash water or other needs. I use groundwater from an aquifer about 75 ft. deep and this water is sterile when it is pumped from the well. Unless I disinfect the water in the tote, algae will start to grow and the water will turn green. Once disinfected, this doesn't happen, since the tote is capped and nothing gets in. I keep my irrigation water in blue LDPE drums that are opaque. I don't mind algae in my irrigation water, but it plugs the drippers.

It may help to think of it as pasteurization rather than sterilization. Pathogens are killed at sub-boiling temps if held there long enough.

Cheers,