A Discussion on Backcountry Water Quality
REI asked 2 water-quality experts their views of water found in the wilderness.
John Collinsis a regional public health officer from the Centers for Disease Control and Prevention (CDC) who serves in the Denver office of the National Park Service.
REI:What is the best way to treat water taken from backcountry sources?
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Collins:"Our posture is that the water should be boiled for 1 minute or, at elevations higher than 3,000 feet, for 3 minutes.
An alternative to that is both filtration and disinfection. First filter the water with an absolute 1-micron filter, not a nominal 1-micron filter. Then take typical household bleach with about 5 1/4 percent sodium hypochlorite and treat the water with 8 drops per gallon, or 2 drops per quart. This is the safest way to remove or kill the microbes, the small bacteria and viruses, which might be in the water.
You can carry a little bit of bleach with you in a small bottle that has an eye dropper. After you add the drops, put the top on and shake it up, then let the water sit 15 minutes before drinking. That gives you safe water.
Q:Why not first treat the water chemically, then filter it? That way you might eliminate some of the chlorine taste.
A:We think it's smarter to get the large hunks out, then kill any little pieces that are left. People should use unscented bleach. Iodine is also very effective in disinfection. However, the taste of iodine is more pronounced and a lot of people don't like it. There's also a small portion of the population that has an intolerance for iodine, especially people with thyroid problems. |
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Q:Some people say they have explored the backcountry for years, have drunk straight from streams and lakes and have never become ill.
A:We hear that all the time. "I've been doing this for years," or "Drinking this water was good for my dad and it's good for me." People see how clear the water looks and think there could be nothing in it that could possibly harm them. That's a misconception among many people who travel in the backcountry. If any water is not posted as potable drinking water, you should treat the water. If you don't, you're taking a chance and it's possible you're going to get caught.
Q:But some people do drink untreated water in the backcountry and do not get sick. Why is that?
A:Well, when you consider the total population that is drinking water in the wilderness, some people are simply more healthy than others. Then you have immuno-compromised people who have a low tolerance for bugs, and they'll be more strongly affected. The same level of contamination will affect people differently. A few people can just shrug off contamination in water. Others can become quite ill.
Just because a source is not contaminated when you drink from it one time doesn't mean it will be uncontaminated the next time. Did a deer or bear make a visit since the last time you drank from that spot? Did a bird happen to defecate on the edge of the water? Could a beaver pond be above you? When we address the general public, we recommend that everyone take the safest possible approach, and to us that's disinfection in addition to filtration.
Q:Have you ever become sick yourself after drinking water in the backcountry?
A:Years ago I was moose hunting in Alaska. I carried a canteen of good water with me, and at one point I shot a moose away from a stream in the area. I decided to take a drink from the stream while I was there. It was good, clear water, flowing fast. I figured there was nothing in it that was going to hurt me. I was in my early 20s, feeling macho. Well, I unknowingly drank some giardia with the water, and it was the best diet I was ever on. I lost 20 pounds in 3 weeks. The diarrhea was not pleasant.
Q:Is flowing water cleaner water? Most people have probably heard it said that water naturally cleanses itself after traveling a certain distance. Is that accurate?
A:Sunlight and oxygen are natural purifiers. Flowing water is being reoxygenated as it moves along. This helps degrade and reduce the organic level of the water, thus tending to purify it. But it's my understanding that giardia cysts, for example, can survive for lengthy periods of time in water—even in very cold situations—without a host. That means users of these pristine-looking streams could be vulnerable to infection.
Q:What about springs? Is it safe to drink straight from one?
A:As it passes through the earth, water can be naturally filtered as it moves through gravel, silt and clay. The water is strained as it passes through, trapping bugs. But some springs could be moving through fractured rock, such as limestone. In those situations, the water can pass through rock virtually unfiltered. So if you see a spring coming from rock fissures, it can be just like drinking water from a stream, and it's best to treat what you drink.
Q:What tips can you offer for selecting water in the backcountry?
A:Look for water that is very clear—not cloudy or turbid. Be concerned with water that has tea-like stains in it, like swamp water. It could have a fairly high level of organic compounds in it from things like decaying leaves or pine needles and those could give you the trots.
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Phil Pollardis a regional public health officer from the Centers for Disease Control and Prevention (CDC) serving in the Olympia, Wash., office of the National Park Service.
REI:Should anyone drink untreated water while in the backcountry?
Pollard:"If they don't care about their health, sure."
Q:Why should we be wary of water in the backcountry when it looks so pure?
A:There are more and more pathogens, or disease-causing agents, in raw water these days because, in my opinion, the backcountry is being frequented by so many people who love the wilderness. The pressure is becoming greater and greater on the land, and not all of these people are careful about how they dispose of their feces. This is how water in the backcountry becomes contaminated—by contact, either directly or indirectly, with feces from animals or humans.
Q:Some people travel to some pretty remote areas in the wilderness, or places above 10,000 feet where fewer people and animals visit. Is that water safe to drink?
A:From a public health standpoint, we always tell the public that water in the backcountry is not safe to drink without treatment. The problem with using a number like 10,000 feet as a safety line is that you can't always tell what the visiting pressure on a particular area has been. You could go to Camp Muir on Mount Rainier, for instance, and be above 10,000 feet. But about 10,000 climbers congregate there every year. Even though Camp Muir has a water system in place, I tell people to filter and disinfect water in the area. You may climb to a very high lake, but you have to ask yourself: Could a bird fly here and leave something in the water?
Q:Some people simply choose to drink untreated water in the wilderness.
A:Even with all the recommendations rangers make to visitors, I'm not so naive to believe that it doesn't happen. What's been surprising to me is how many times I've visited with folks who seem to be strong, healthy individuals and heard them tell stories of becoming sick with confirmed cases of giardiasis. One person told me he needed 18 months to get over the symptoms.
Q:Some people claim to regularly drink straight from streams and never show signs of being sick.
A:"There's no way of separating the healthy and hardy people from those who are more vulnerable to disease. Some people harbor suppressed disease, which puts them at greater risk for illness. A person might be taking an immune-suppression drug for a drug transplant, and that person would be at greater risk of contracting a disease. From a public-health standpoint, we have to make recommendations that protect all classes of people. So we recommend filtration and disinfection."
Q:Does anyone really know what's in the water in the backcountry?
A:First, it's difficult to evaluate water in the wilderness. It's expensive to collect samples and evaluate them in a lab. Second, all you're doing is taking a grab-sample at a random time. The sample may not have any giardia or cryptosporidium present, but 5 seconds later it may be there. That doesn't tell you any thing about the long-term quality of raw water. You have to do continuous sampling to be accurate. You have to assume pathogenic organisms are out there, because we know they are there at some point in time. I'm aware of a study that showed up to 40 percent of backcountry visitors can have giardiasis and are not symptomatic of the disease. Even though they don't show the symptoms, their feces have giardia in it, and any exposure to those feces means the next person could get it.
Q:Can people drink safely from springs without treating the water?
A:For the general public, the answer is no. Springs fall into 2 different categories: They deliver either groundwater or surface-influenced water. But until you do a sophisticated set of samples of any number of springs, you can't tell.
Q:What's a surface-influenced spring?
A:This is where surface water has the ability to flow into a spring. If that occurs, it is possible pathogenic organisms are in the water. If, on the other hand, the spring is not open to the atmosphere, that spring should be safe. But unless you perform microscopic particulate analysis, though, you can't tell one from the other.
Q:Would you ever drink straight from a spring?
A:I probably would not. My health is good. I'm not in an at-health risk category, but I guess I'm more sensitive to water-quality issues than the average backcountry visitor.
Q:A lot of groups—the government, environmental groups, retailers and manufacturers—have made an effort to make the public aware of proper sanitation techniques. Is it helping?
A:There's a stronger backcountry ethic these days, and I notice it especially in the West. Still, from what I hear from the parks, unless the park provides some means of waste disposal in the backcountry—privies at trail camps or blue bags at Camp Muir on Mount Rainier—it's my experience that people are just messy. There are a lot of slobs out there, and that's a shame because there are also a lot of knowledgeable people who demonstrate good backcountry integrity. Still, the safest thing you can do is filter and disinfect all water before you drink.
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