Backpacking & Hydration
Backcountry Water Purification

Backcountry Water Purification & Hydration

Finding water isn't usually an issue while backpacking in Yellowstone. Most backcountry campsites in the park are conveniently situated near reliable water sources so you'll have access to water for cooking, cleaning and drinking, but as tempting as it may be to quench your thirst in one of the many crystal clear mountain streams we always recommend boiling, chemically treating or filtering your water to prevent waterborne bacteria like Giardia and Cryptosporidium from entering the body. These intestinal parasites are spread through water supplies, the fecal matter of infected animals or humans and can easily contaminate your drinking water. Treating all water is a must. While the symptoms may not occur for days or even weeks after the trip, the end result is always the same; a week or more of severe diarrhea, bloating, stomach cramps and nasty gas. Not the best way to remember your backpacking trip to Yellowstone.

During most backcountry outings you'll probably rely on a combination of the techniques listed below to help you purify your drinking water. Take the necessary precautions and check with rangers regarding available water sources along your route. All water should be carefully filtered or boiled before drinking.

CAUTION: Do not attempt to obtain drinking water from geothermal features or hot springs. Many of these water sources contain high concentrations of dissolved minerals that may be unsafe to drink.

Staying Hydrated When Hiking And Backpacking

Because much of Yellowstone is located at elevations above 5,000 ft. it's important to increase your fluid consumption when hiking or backpacking at this altitude. The increase in elevation and activity level means you'll be losing water through perspiration and respiration at a much higher rate. During the warmer months it may be easier to gauge the effects of water loss but in colder temperatures you may not feel the need to drink as often and you may be unaware of just how much fluid your body has lost during these strenuous activities. You should be replacing fluids often when traveling in the backcountry.

Naturally fluid intake will vary from person-to-person depending on their fitness level and conditioning. On a backpacking trip or a long day hike the average person may require a gallon of water or more per day depending on the duration of the hike, elevation, intensity and weather. This amount may seem excessive but it's necessary to keep your body functioning properly and prevents the onset of muscle cramps, dizziness, headache and fatigue. For longer day hikes you should consider carrying a portable water filter so you can replenish water supplies along the way. This will keep your pack weight to a minimum and gives you a reason to stop and enjoy the scenery.

If you're unsure of how much to drink simply monitor your urine output throughout the day. This will be a good indicator of how well hydrated you are. Light colored urine means you are well hydrated while darker colored urine probably means you are dehydrated.

If you carry water bottles keep them accessible so you're more inclined to drink continuously throughout the day. If you place them inside your pack you may it inconvenient to stop and drink as often as you should. A CamelBak® hydration system is ideal for maintaining good hydration and the smaller flow tubes encourage you to sip water rather than gulping down large volumes during a hike. If you'd like to monitor your water intake Camelbak® has just the thing. The 'Antidote™ Insulated Tube with Flow Meter' does just that. This handy little computer device clips directly to the drinking tube and will tell you how much water you've consumed and how much water is left in your reservoir. Very cool!

Being well hydrated means improved performance on the trail and it will help prevent heat and cold-related ailments like heat exhaustion, heat stroke, heat cramps, frostbite, hypothermia and altitude sickness. Keep the water flowing and you'll keep your body going.

Boiling Water

This method is foolproof. Just bring water to a rolling boil for about 1-2 minutes. Boiling water will kill bacteria and viruses and is easy to accomplish while you're in camp or during meal preparation. It is however a less than practical method when and if you need a constant supply of drinking water while on the trail. Larger hydration systems like those from Camelbak® or Platypus can make water intake that much easier throughout the day but can add significant weight to an already heavy pack.

• 1 gallon of water weighs approximately 8 pounds.
• A 100 oz. water bladder can add 6 pounds to the weight of your backpack.
• 1 gallon = 4 quarts = 8 pints = 128 fluid ounces.

Here are a few manufacturers of lightweight backcountry camp stoves for cooking and boiling water.

Jetboil makes a variety of super fast cooking/water boiling systems.
MSR makes quality backcountry stoves, cookware, water filters, snowshoes and tents.
Primus offers a variety of camp stoves, headlamps, and tents.
Coleman makes just about everything for camping.

NOTE: Most backcountry stoves run on either white gas or propane/isobutane/butane blends and some can even utilize gasoline or kerosene. White gas performs better during colder temperatures but the stoves require regular priming to maintain the flow of fuel. Propane stoves do not require priming and the fuel is lighter and more convenient to carry but their heat output is greatly affected by temperatures below freezing. As with any outdoor gear, it's important to spend time getting to know how your equipment operates especially if it's brand new. You should always carry the necessary spare parts in case you need to make repairs in the field.

Portable Water Microfiltration Systems (Pump Style Units)

This is the most common not to mention the most time-consuming way to treat your water. These filtration systems are great for trapping most bacteria but they may not filter out all viruses. In the U.S. this may not be as much of an issue but in other parts of the world it could lead to illness. When deciding on a water filter system look for one that has an absolute - not nominal - pore size of 0.2 - 0.3 microns. This is the industry standard and indicates the system's smallest microbe filtering capability.

These lightweight pump-style microfiltration systems usually consist of a lever mechanism (pump), glassfiber/carbon filter (replaceable), plastic intake and delivery hoses and a pre-screening filter for keeping out larger rocks and sand particles. They are also equipped with adaptors that will fit your Nalgene® bottle or water bladder. This adaptor makes filling containers much easier.

NOTE: Rivers or water sources with high concentrations of sediments can clog the filters of these devices so carry the appropriate cleaning tools or replacement cartridges. In some cases it may be advisable to carry a larger portable container which can be used for holding water until the sand or sediment has settled to the bottom.

*** This method is not recommended for winter use or temperatures below freezing.

Microfilter Manufacturers
Katadyn is synonymous with water filtration systems.
MSR has a great reputation for backcountry gear.
PUR makes both backpacking and in-home water filtering systems.

Gravity Fed/Pour Through Filters

Katadyn makes a large capacity, gravity fed treatment system called the Base Camp which can treat up to 200 gallons of water, requires no pumping, and is ideal for use with larger groups or as an option for your base camp water needs. Just hang the bladder from a tree or pole, release the flow valve and you've got drinking water. The unit can quickly filter 2.5 gallons of water in about 15 minutes and allows you to spend more time relaxing and less time bent over a stream pumping water.

*** This method is not recommended for winter use or temperatures below freezing.

Chemical Treatments (Iodine)

These tablets are very inexpensive and are easy to carry and store but may not be as effective against Cryptosporidium. The iodine leaves water tasting funny but it works great in a pinch. Two small iodine tablets will treat about 1 quart of water. Iodine is effective against bacteria, viruses and giardia but does not work against Cryptosporidium (see description below).

When purifying colder water the treatment time will increase significantly—almost an hour for water below 40º. For cloudy or dirty water the number of iodine tablets should be increased as well. If possible it's always best to pre-filter cloudy water with a cloth bandana or another article of non-essential clothing. This will remove the larger sediments and particles and makes treating dirty water a little easier. Do not attempt to flavor the water until the iodine treatment has had a chance to work. Some drink mixes contain vitamin C which will act on the iodine itself rendering the process ineffective.

Potable Aqua Water Treatment Tablets

Ultraviolet (UV) Treatments

SteriPEN® is a great alternative to the hand pumping systems and uses ultraviolet light to kill the contaminates (bacteria, viruses and protozoa) in the water. It only takes about 1 minute to treat a 32 oz. Nalgene bottle. If you enjoy shedding the extra weight and would rather not carry lots of water during the day this is a great solution. It makes filtering water quick and easy and the unit can be purchased with an optional solar charger. the SteriPEN® is best used with a wide-mouth Nalgene bottle and runs on CR123 batteries.

NOTE: If you plan to keep you pack weight to a minimum by carrying less water make sure you have reliable water sources along your route. Some small streams and creeks may be dry during the warmer summer months making the distance between refills much greater.

Common Waterborne Bacteria & Infections

Cryptosporidium also known as Crypto is a waterborne parasite that causes severe gastro-intestinal illness and diarrhea. The incubation period is anywhere from 7 days to 2 weeks, and may be accompanied by abdominal cramping, nausea, vomiting, fever, headache and loss of appetite. Pregnant women, young children, and individuals with weakened immune systems are more likely to become seriously ill if infected with the parasite. It can take a healthy person at least two weeks to recover once the infection takes hold. Treatment usually involves fluid replacement and electrolyte supplements. Boiling your water is the safest way to kill this parasite.

Also know as Giardia intestinalis, Giardia lamblia, or Giardia duodenalis is a hikers worst nightmare. Much like Cryptosporidium this is a nasty intestinal infection accompanied by abdominal cramps, bloating, nausea and bouts of watery diarrhea. Giardia can be transmitted in food, water or by contact with an infected person. Symptoms may not occur for days or weeks and symptoms can last for months. Treat all suspect drinking water by either boiling or filtering when in the backcountry. A little prevention goes a long way.

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