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Paddling Articles In the Same Boat

Alimentary, My Dear

Water, Water, Everywhere,
But Not a Drop to Drink?

By Tamia Nelson
tamia@paddling.net

July 16, 2002

A gentle breeze ruffles the lake surface under a brilliant blue sky, but the moving air does little to cool your sweating body. The noon sun is so hot that it feels as if it's drilling a hole down through the top of your head. Your mouth is dry, and your tongue feels swollen. You need a drink. Now.

You stop paddling. Your boat drifts with the wind. You rummage around in your pack and pull out your water bottle, only to find that the cap has come loose. All the water has seeped away into your spare clothes. Except for a few tepid drops, the bottle is empty. You look around you. Wavelets lap tantalizingly against your hull. The lake is crystal clear. You can see the bottom. It must be twenty feet down, but it seems as if you could reach out and touch it. Then you bring the water bottle to your parched lips and tilt it up. The last drops run into your mouth, but they do nothing to quench your raging thirst.

You soak your bandanna in the lake and wash the salt crust from your face and neck. You dip it in the water again, then tie it around your neck. You lick a few drops of water off your lips. Heavenly!

Water, water, everywhere…. And why not take a drink? You study the shoreline. A few cottages are just visible in the distance. Surely, you think, they wouldn't…. They aren't….? You shake your head. You sigh. Then—quickly, so you won't have time to change your mind—you hold your water bottle over the gunwale. Lake water flows into the open neck, filling it in no time. You lift the bottle to your lips. Cool water gurgles down your throat. Ahh….

Satisfied now, you refill the bottle, check to see that the cap is secure, and stow it away in your pack. By the time the sun has dipped below the trees to the west, you're at the take-out, loading your boat onto the van. In less than an hour, you're seated at an outside table at Hog Heaven. The waitress puts a cold beer in front of you and tells you that your order of ribs is on the way. You smile your thanks and settle back. Life doesn't get any better than this, you think.

Two hours later, you pull into your driveway. You're exhausted. You leave the boat on the van, take a quick shower, and go to bed. You fall asleep in seconds.

The first cramps hit at four o'clock in the morning. You make it to the bathroom in time, but the vomiting starts before you can get up off the toilet. The next three hours are best forgotten. You skip breakfast and call in sick. The boss isn't very happy, but you don't care. You think you're lucky to be alive. Then you head for the doctor, hoping that she can fit you in. She can—just. She gives you a quick once-over and tells you that you have a "stomach virus," or maybe "beaver fever." Then she leaves. Her nurse hands you a prescription and tells you to drink plenty of water.

Water! you think. That's what caused all this trouble! But you don't say anything. You're already feeling better. You put the prescription in your wallet and stock up on bottled water at the Quik-Mart. You're not taking any chances.

*   *   *

A month passes, and you're back on the lake. It feels good to stretch your muscles again, to feel the hot sun on your face, to revel in the freedom of the water. Around noon, you stop for lunch: a thick ham sandwich and a couple of big chocolate chip cookies, along with some salted peanuts to finish things off. Then you grab your water bottle. You've learned your lesson. The cap's screwed down tight. You loosen it and upend the bottle over your open mouth. Water—safe water—pours out. You drink greedily. When you finish, the bottle's almost empty. Guess I should have brought another bottle, you think. Still, you've quenched your thirst. And anyway, there's nothing you can do about it now.

The long summer afternoon passes slowly. The temperature climbs. You sweat. Salt stings your eyes. Your mouth is dry. But your water bottle—your only water bottle—is empty. You look out at the lake. Its water is cool, clear, inviting. Then you remember the morning after your last trip. There's no way I'm going through that again! you tell yourself. So you paddle on through the furnace of the day.

Later, at the take-out, you're a little sick to your stomach. You're light-headed, too, and you feel weak and washed-out. You even have trouble getting your boat on the van. You stop at the first roadside stand you come to and order two large root-beers. You drink both of them, then order a third. It does the trick. Your head clears. You feel stronger. You drive away refreshed. The next time, you promise yourself, I'm going to bring at least a gallon of water from home. And you do.

*   *   *

Get the picture? Paddling's sweaty work, and you need plenty to drink if you want to stay healthy. But you can't assume that the water you paddle is safe. No matter how clear it is, it can still harbor dangerous microorganisms, or even toxic chemicals. There's no rule of thumb to distinguish good water from bad, and no simple test. The only universal guideline is the one promulgated by veteran desert walker (and occasional paddler) Colin Fletcher: "When in doubt, doubt." And sadly, there's almost always good reason to doubt the safety of the water around you. Don't blame the beaver or other wild animals, though. Notwithstanding the "beaver fever" tag, the culprit in most cases is…you guessed it…us: paddlers and other boaters, waterfront property owners, or town and village sewage systems, not to mention our pets and our industries.

OK. The water's probably not safe to drink. What can you do about it? The first and most obvious alternative is to bring good water from home. There's a problem, though. A US pint of water (about half a liter) weighs a little more than a pound, and you need at least a gallon of fresh water each day. That's more than eight pounds! (Think a gallon is a lot of water? The US Army's desert warfare allowance is eight quarts—two gallons—a day. And the Israeli Defense Force go even further: heat illness is a court-martial offense, and they provide each soldier with a daily ration of ten liters—more than two and one-half US gallons.)

Eight pounds (or more) of water, each and every day. That's all right on a day trip, or even on a weekend—if the portages aren't too steep!—but it's not very practical on longer voyages. That leaves you with just one choice: treat the water to make it safe.

But how? No treatment can make chemically contaminated water fit to drink, of course. Still, chemical contamination isn't thought to pose a danger in most back-country areas. And how can you tell if it's a problem where you want to paddle? You'll have to rely on local knowledge. So ask around. Contact paddling clubs. Natural resource agencies. Public health authorities. Even local universities. And hope that you get honest answers.

Happily, you can do something about microbial pathogens—nasty bugs, in other words. Boiling works fine, for instance. But boiling water takes time and fuel, and even regular tea-drinkers may find that a hot cuppa doesn't do much to quench their thirst on a steamy summer afternoon. (In fact, tea and coffee both contain caffeine, and caffeine is a diuretic. It makes you pee. So coffee and tea can actually increase the threat of dehydration, at least when drunk to excess.)

All right, then. If boiling's not practical, what about filtration? It's a popular choice. The catalogs are full of water filters. And for good reason. Filtration works well, provided that the filter is carefully maintained and the "bugs" in the water you're filtering are fairly large. Most filters do a good job with the cysts of protozoan parasites (the misnamed "beaver fever" organism Giardia, for example) and bacteria. But tiny viruses can slip right through the filter pores, and that's not good news, because viruses—among them the hepatitis complex—are among the ugliest of waterborne nasties.

This is a problem. If filters can't remove some of the deadliest pathogens, what's a paddler to do? The answer, I'm happy to say, is simple: treat any water drawn from lake, stream, or spring with a chemical biocide. Iodine is the chemical of choice, and tetraglycine hydroperiodide tablets (sold under the trade mark Potable Aqua®) are the easiest way to deliver a measured dose. One tablet in a quart of water will yield a concentration equivalent to 8 milligrams of free iodine per milliliter (that's 8 parts per million, or ppm). Given adequate time to do its work—a "contact time" of ten minutes or more—this concentration is high enough to reduce the numbers of bacteria, viruses, and most protozoan parasites to safe levels.

Is there any downside to iodine? Yes. People with thyroid disorders or iodine allergies should not drink water disinfected with tetraglycine hydroperiodide (or any other iodine-releasing compound, for that matter). And tetraglycine hydroperiodide tablets must be fresh to do the job. They should be stored in a tightly capped bottle and kept in a cool, dry place. Any tablets left over at the end of the season should be discarded. The water to be treated must also be comparatively warm and clear. If it's cloudy or cold—less than 40 degrees Fahrenheit, say—double the dose to two tablets per quart, and double the contact time (to 20 minutes) as well.

Anything else? Yes. At concentrations of 8 ppm (or more), iodine imparts a distinct—and, to some people's palates, distinctly unpleasant—taste to water. This taint can be removed by subsequent chemical treatment or activated carbon filtration, but there's another, simpler alternative. Concentrations of as little as 0.5 ppm will kill all but the most resistant encysted protozoan pathogens. That being the case, if you're traveling outside the tropics, if your immune system is up to par, and if you're willing to run the usually very small risk of giardiasis (a subject of "exaggerated concern," in the words of one authority, the invaluable Medicine for Mountaineering), then, and only then, you may wish to treat drinking water in bulk, using just enough tetraglycine hydroperiodide to yield a final concentration of 1 ppm: one tablet per two gallons of (clear) water. To be on the safe side, allow a minimum one-hour contact time, too.

This is what Farwell and I do, and we've been happy with the results. The iodine taste is barely discernible, yet the treated water is as free of microbiological hazard as the stuff that comes out of most urban taps. (Few municipal systems filter out cysts, and chlorine can't always be relied upon to kill Giardia.)

Of course, there's no reason why you can't combine chemical treatment and filtration. Just treat your water with iodine tablets and then pump it though a filter. It's the belt-and-suspenders approach, and it ought to provide a very high level of protection, indeed. In fact, several commercial water filters formerly incorporated iodine-impregnated elements, thereby attacking microbial contamination in two ways at once. I can't find any of these in my current catalog collection, though.

Water, water, every where/Nor any drop to drink. Unfortunately, the Ancient Mariner's familiar lament is often as true of today's recreational waterways as of Coleridge's "painted ocean." And even a little thirst is a dangerous thing. No paddler can afford to be without plenty of clean water. "Clean"—that's the critical word. So when in doubt, doubt. It's the only safe rule. Once you've treated your water, however, you should be able to put those doubts to rest. Then you can drink a toast to your good health with confidence. Salut!

Copyright 2002 by Verloren Hoop Productions. All rights reserved.










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