Are we just kidding ourselves with our chemical water treatments?

[Derek M.]

I've now read what seems like the 100th post-PCT thru hike gear review where the author states something to the effect of:

"At first, I used a filter (sawyer mini, sawyer squeeze, whatever…), but it quickly clogged and I became tired of the low flow rate and the general hassle of filtering. Once I got to the Sierras, I just used bleach drops instead and it worked great, so I sent the slow filter home!"

This has gotten me thinking about how much we all might just be kidding ourselves with the effectiveness of our chemical water treatment.

The Centers for Disease Control and Prevention (CDC) clearly states here and here that chlorine (i.e. bleach) is ineffective at killing Crypto and has only low to moderate effectiveness at killing Giardia. It's effectiveness at the actual concentrations used by most backpackers, might be even lower.

Additionally, the CDC also states that chlorine dioxide (i.e. aquamira) has only low to moderate effectiveness at killing Crypto, though unlike bleach is highly effective at killing Giardia.

Let's be honest, very few of us wait the actual 4 hour period of time prescribed for killing Crypto with aquamira (drops or tablets, it makes no difference, just ask McNett– though this is a common misconception).

Clearly, many of us (at least lots of these PCT hikers I'm reading about) also just use bleach, so effectively killing a real Crypto threat in this scenario is totally out of the question.

So what I'm getting is this:

1) People using the two common chemical water treatment methods (bleach or aquamira) are probably safeguarded quite well against bacterial and viral infections from their treated water.

2) People using aquamira are probably safeguarded quite well against Giardia infections from their treated water.

3) People using aquamira are probably not safeguarded very well against Crypto infections from their treated water.

4) People using bleach are probably not safeguarded very well against Giardia infections from their treated water.

5) People using bleach are definitely not safeguarded against Crypto infections from their treated water.

So in summary, whether using bleach or aquamira, and using it in the way that we all commonly do (i.e. not waiting for hours and hours before drinking and also often treating very cold water), we seem to be opening ourselves up to protozoan infection by either Giardia or Crypto (or both).

These are the pathogens that people seem to worry most about, but we are actually doing the least to protect against them when using chemical treatment.

So my question is, are we just kidding ourselves with our chemical water treatments? If Giardia or Crypto are actually in that water, are we going to get sick anyway?

If so, why even treat?

Is there any actual data on the prevalence of Giardia and Crypto in backcountry water sources where backpackers commonly collect water? I've been very frustrated in my own limited search, having come up pretty much empty handed trying to find real data concerning this topic.

Thoughts?

[Roger Caffin]

I am sure the vendors of chemical treatments will throw up their hands in horror at what you are implying. Outrageous! Hazardous to human health! Should be censored. etc etc.

Sue and I gave up treating mountain water some years ago. We only treat where there are clear signs of humans or domestic animals. And generally we KNOW where those hazards exist.

OK, we carry a Steripen Opti (or Classic 3). Yes, it is effective against viruses, bacteria and protozoa – immediately (>90 seconds). But we rarely use it.

We have not gotten sick from water.

Cheers

[Christopher *]

You are also not accounting for the fact that LOTS of PCT thru hikers get sick at some point during their hike. It doesn't always make the blog-rolls.

My year (2012) there was a bad outbreak of campibacteriosis (diagnosed at a clinic) that started somewhere around Tehachapi and then something else just after Hat Creek rim that hit at least half the herd on both accounts.

It is also a hidden secret that it is not terribly uncommon for a PCT thru hiker to soil themselves at least once during their hike. Leaving town having gorged yourself on lord-knows-what to return to a diet of dehydrated whatever leaves the GI tract in a state of constant distress. Sometimes it's hard to tell if you have a stomach bug, or are just suffering from post-townstop-pooposis. What I can tell you though is stomach ailments are pretty common.

[Bob Moulder]

On several occasions this past summer I was forced to take water from some very undesirable sources such as standing water in a nearly dried-up artesian spring outlet, and warm standing water from a swamp.

I used the AM pre-mix system and did not get sick. Maybe I wouldn't have gotten sick anyway, but I strongly suspect there would have been severe digestive implications.

Even if it doesn't kill everything it is still far better than nothing in certain situations. The only water I don't treat is the stuff coming from springs straight out of the rocks. I've never treated that water and I've never gotten sick.

[Owen McMurrey]

"Is there any actual data on the prevalence of Giardia and Crypto in backcountry water sources where backpackers commonly collect water?"
If there was, would it be meaningful? What backcountry? Where?
How often do we actually collect water at the source?
I don't think this is something that can be put in a box.
The risk isn't the same everywhere. It's not necessarily the same in the same place from one minute to the next, because this stuff is not part of the water, it's introduced at some point, and diffused at some unknown rate.

It's one thing to be getting water from a spring 10k' up in the Sierra, but around here, a fool and the contents of his digestive system are soon parted.
We have a lot of state parks and wilderness areas bordered, if not surrounded, by agricultural development. We've got gorges with beautiful waterfalls of clear, cool, rapidly flowing, altogether inviting water streaming through woods full of wildlife, and fed by drainage from farmland, cow pastures, etc. contaminated with feces, probably pesticides, herbicides, dead bodies(hopefully all animals!), and who knows what else.
I don't fully trust any method, but it's definitely getting filtered.

[Jerry Adams]

About half the time, I drink good looking mountain water and have never got sick, that I know of.

Sometimes, a Giardia infection can have no or very mild symptoms.

I carry a Squeeze because its so light, and since it's so easy, I use it about half the time. I use a re-used soda or water bottle to squeeze out of. That does not fail, because there are no seams. It takes 1.5 minutes to squeeze out a pint. No big deal.

Getting sick from water is a statistical thing. You probably won't get sick just one time. Probably, over a lifetime, you'll get sick a few times if you drink untreated water. Most all people, over a lifetime, get a little sick from something so it's hard to know if it was the water. Just because you haven't got sick that you know of, doesn't mean you shouldn't treat in the future.

[Buck Nelson]

You make a lot of very good points Derek, and you've clearly done better research and put more thought into the issue than most hikers.

Perhaps it's a bit like wearing a bicycle helmet. A helmet won't be 100% effective, but it will dramatically increase our safety.

Personally, I think bleach is a rather poor choice vs Aqua Mira since it is far less effective for giardia, which is my primary concern.

It is true that Aqua Mira is far less effective on crypto than giardia, however even if a typical hiker doesn't wait the full four hours to get the "3-log reduction" it will still be somewhat effective with lesser wait times. For example, 30 minutes is supposedly enough time in clear, warm water. https://www.inkling.com/read/wilderness-medicine-auerbach-6th/chapter-67/chlorine-dioxide

So with Aqua Mira, properly used, I can kill virtually all viruses, bacteria, giardia and significant amounts of crypto, that's a good reason to treat.

The EPA Giardia Drinking water health advisory has the results of many studies. Do a search for "pristine" and see what was found in the waters. One quote: "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." http://water.epa.gov/action/advisories/drinking/upload/2009_02_03_criteria_humanhealth_microbial_giardiaha.pdf

[Andy F]

"So in summary, whether using bleach or aquamira, and using it in the way that we all commonly do (i.e. not waiting for hours and hours before drinking and also often treating very cold water), we seem to be opening ourselves up to protozoan infection by either Giardia or Crypto (or both)."

I agree. I generally don't treat or filter flowing water from remote mountain areas. I've gotten sick (sometimes nearly needing to go to a hospital due to dehydration) from eating at restaurants, but never from drinking mountain water in areas like WV and the UP.

I suspect that puddles, small ponds, swamps and other stagnant water are more likely to harbor amoebas and parasitic worms. I either filter or boil if I need to use water from those sources as a last resort.

[Elliott Wolin]

I've posted this before, but an Aquamira rep once told me a great way to get good water quickly is to use the drops/pills to kill the small stuff, then use an Aquamira Frontier Pro straw filter to remove the big stuff, i.e. Giardia and (I think) Crypto.

The small stuff goes quite quickly, seconds to a minute if I recall. The big stuff has hard shells that protect it, but it is easy to filter out because it is so big.

The Frontier Pro weighs a few ounces.

[Stephen M]

Thats a great idea Elliot.

[Travis B.]

I tried using the Aqua Mira drops for the first time this past summer and the drops just ended up sitting in my backpack for emergency use. Where I hike the water can't be more than a few degrees celsius year round, so I imagine I'd have to let the drops work for far too long than would be useful. Instead, I carried on my tradition of just drinking water without filtering and trying to make smart decisions about which water sources to use.

[Peter Treiber]

I use Elliott's method. Micropur tablets, wait an hour or so, sip through Frontier Pro. Tastes great, anyway!

[Frank T]

I do the opposite of Elliott, I mix the Aquamira A & B drops and add to water that I've already filtered. Is there any advantage to doing it either way?

[David Thomas]

We spend $7,390,000,000 on TSA for the appearance of safety, so $10 – $50 for (1) the feeling that our treated water is safe AND (2) actually eliminating some pathogens seems like a bargain.

You make excellent points, Derek, and if more people just knew the basics, they might protect themselves more effectively.

I used to primarily use boiling or iodine and now use UV with iodine as a back-up plus boiling somewhat more hot drinks than I would if there was no risk of untreated water. I'm never far from great *looking* water in Alaska, but elsewhere, I'd be ready to double up on the treatment (UV and chemical) for really skanky water.

I know I'm not protected against all hazards and I adjust it somewhat depending on trip length, distance from medical care, and individuals along (under 5s have less developed immune systems). Then I double up more on multiple treatments and/or boil more water.

In heavily sedimented waters, I use a pinch of alum. Partly to improve taste, but more so to greatly increase the effectiveness of chemical and UV treatment and because (while I haven't seen good research on this) I strongly suspect some viruses, bacteria, and cysts flocculate into the floaters and sinkers and get skimmed away.

[Gary Dunckel]

The Frontier Pro filter has a carbon element that removes the chlorine taste, so I like to run the treated water through the filter after the chemicals work for ~20 minutes. Better tasting methinks.

[Roger Caffin]

> inviting water streaming through woods full of wildlife, and fed by drainage from
> farmland, cow pastures, etc. contaminated with feces, probably pesticides,
> herbicides, dead bodies(hopefully all animals!), and who knows what else.

In which case I would not hesitate: I'd use a Steripen. 90 seconds, 1 litre, foolproof.

Cheers
Edit after Tom prompted – if the water has ag chemicals or industrial chemicals – forget it. Not drinking that.
PS: there is a creek draining an old silver mine here in Oz: lots of arsenic!

[Nick Smolinske]

Totally agreed on this – I think Aqua Mira is best when you can treat your water in large batches with a long contact time. This is most useful in the desert, where water sources are few and far between, and you have time to treat overnight.

In places where there is a lot of water, if it's generally trustworthy I'll drink it straight and bring aqua mira in case I can't find a good source. I haven't yet hiked anywhere where I don't really trust the mountain water, but I know those places exist, and one of these days I'll buy a steripen for that sort of situation (and carry aqua mira in small dropper bottles for a <1oz backup).

All of that said, the 3-log reduction (or whatever the standard exactly is, but 3-log was mentioned) is probably conservative in most areas. If you're treating water that's really clean already, it's entirely possible that you *already* have an effective 1-log or 2-log reduction, without treatment, compared to whatever the worst-case baseline is. So you wouldn't need as much contact time in that case. It's all about reducing bacteria to an acceptable level that our body can fight off – not annihilating it completely.

One of these days I'll figure out some math problems based on chlorine dioxide reduction to give to my students when I teach about logarithms…

[Anonymous]

"In which case I would not hesitate: I'd use a Steripen. 90 seconds, 1 litre, foolproof."

Except for the herbicides? ;0)

[Richard Gless]

I've backpacked for many years on the West Coast and never had a problem getting sick from the drinking water, although. I have had the occasional bout of "post town pooposis" on longer hikes. I do tend to camp near tree line and try to camp away from people and popular camping areas. I also pay attention to the water source – if the water looks like it should be clean (e.g., coming out of a snowbank), I rarely treat it. Early on I just used the occasional iodine tablet, then went to a filter when everyone started worrying about the water quality, and over the last 10 years moved to chlorine dioxide tablets in an effort to lighten my pack.

I wonder if one is careful and makes a point of getting their water from the top inch or two of lakes and ponds, the irradiation by the mountain sunlight doesn't kill most if not all of the nasties (http://en.wikipedia.org/wiki/Solar_water_disinfection). A little follow-up with chlorine finishes off what's left. I've used some pretty manky water from ponds dried up streams in meadows in Emigrant in the last few years and again had no problems. Wouldn't the sunlight essentially do what a Steripen does? Just a thought.

[Anonymous]

"I wonder if one is careful and makes a point of getting their water from the top inch or two of lakes and ponds, the irradiation by the mountain sunlight doesn't kill most if not all of the nasties (http://en.wikipedia.org/wiki/Solar_water_disinfection). A little follow-up with chlorine finishes off what's left. I've used some pretty manky water from ponds dried up streams in meadows in Emigrant in the last few years and again had no problems. Wouldn't the sunlight essentially do what a Steripen does? Just a thought."

I operate on the same hypothesis, so far without incident, but without taking samples from deeper in the lake, there's no way to know.

[Anonymous]

It's an interesting question and issue and definitely worth some research. However, thinking about it holistically, even in seemingly still lakes and ponds, there is a certain amount of constent convective cycling of water due to hot and cold interaction between surface and deeper layers of water.

The question is, is for how long is that relative layer of water near the surface, and is it long enough for such solar disinfection to occur? I have no idea.

[M B]

No, we are not kidding ourselves.

You fail to see, that cryptosporidium simply is not a problem. We can ignore it, until people get sick from it.

AM is highly effective agaist Guardia. In fact, it will reduce it 1000x in only about 5 minutes. You don't need to wait 30 min. That is for cold water, organic matter, and loaded with cysts. If you are drinking flowing water, you wouldn't expect to get many cysts in 1 L of water.

Most gastro problems are probably bacteria, that is handled in under a minute by AM.

The proof is in the results. People simply aren't getting sick. But you would propose we aren't doing any good?

It certainly helps that most water probably doesn't need treating anyway. As much as 25% of the population may carry Giardia and be asymptomatic ad well.

[Dan @ Durston Gear]

My approach is simple and based on a few fundamental principals:

1) Giardia is common, while crypto is rare.
2) Getting sick once in a while is okay.

The only tool in my water treatment arsenal is AquaTabs pills, well there's also a bandana for pre-filtering really gross water. These pills are like Aquamira tablets but much cheaper and smaller ($10 for 50, even cheaper in bulk). When water quality is good, I don't use them and thus run a small risk of getting sick. When water quality is poor I use them, and still run a small risk of getting sick from crypto etc.

On the PCT this summer everyone had those Sawyer squeeze filters which looked like a huge pain in the butt. So much effort required for so little water. It seemed like everyone had tossed them by 1/2 way. Steripen's are a neat idea. It's a bit more cost and hassle then I'd like but it's a cool solution. I saw none on the PCT.

My wife and I used these AquaTabs in SoCal where the water quality is poor, but even here 1/2 the water is potable water from cache's so you're not always treating it. Beyond SoCal I just drank the water 95% of the time, and treated the 5% of water sources that looked the most impacted/stagnant. I never got sick, but I was okay with getting sick.

[Valerie E]

I love my Steripen, and wouldn't trade it for anything else (Aqua Mira is my backup, and it's my husband's preferred method).

BTW, Carrot Quinn used a Steripen on the PCT 2013 and 2014 until the last couple of hundred miles (when it finally broke – but +/- 5,000 miles on one Steripen is not bad, IMO).

[Roger Caffin]

> You fail to see, that cryptosporidium simply is not a problem. We can ignore it,
> until people get sick from it.

To paraphrase that:
You fail to see, that death simply is not a problem. We can ignore it, until people get dead from it.

> The proof is in the results. People simply aren't getting sick. But you would propose
> we aren't doing any good?
Your logic boggles me.
Are you trying to say that because people are not getting sick, whatever they are using must be working?
That's a bit like saying that my prayers to the Flying Spaghetti Monster that I live another day must be working, because I didn't die overnight.

Cheers

[Author]

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