Water is the most important survival need when you head outdoors. Whether you pitch a tent in a developed campground or hike into the backcountry, planning your drinking water supply keeps your group hydrated and healthy. A few simple steps help you bring enough water, know when campground sources are safe, treat backcountry water, and protect natural water from contamination.
Planning Your Water Supply
The National Park Service recommends a rule of thumb of drinking 2 liters of water a day or more, especially if you are in very hot climates. Water is used for drinking, cooking, and cleaning, so you need to plan for all three. When you stay in a frontcountry campground, filling up a water jug is one of the first tasks after you arrive. A collapsible water jug saves space, while a hard-sided jug is more durable but bulkier. Bring refillable water bottles for each person so everyone can carry their own supply during hikes and other activities.
If you are car camping and have a cooler, you can use water to help keep food cold. The National Park Service suggests freezing a few gallons of water in plastic containers and placing them in the cooler. As the ice melts, you gain an extra supply of drinking or cooking water. The park service also notes that in the backcountry you need to choose a campsite near a water source, and you will have to filter, purify, or boil the water you collect. Hauling enough water for an entire backcountry trip is often not practical, so pairing a nearby water source with reliable treatment methods is essential.
Is the Campground Water Safe to Drink?
Campgrounds vary, and some have no drinking water at all. The National Park Service urges campers to know where water is available in the park and whether it is potable. Check with a park ranger or campground host to find out. The CDC warns that in places without sanitation and water treatment infrastructure, including campgrounds, hiking areas, and remote locations, water is more likely to carry germs that can make you sick.
Even if the campground has drinking water, it is wise to confirm that the system is operating normally. If you cannot confirm potability, treat the water yourself or bring your own supply. This is particularly important for families with young children, pregnant women, people 65 or older, and anyone with a weakened immune system, groups the CDC identifies as at higher risk of getting sick from unsafe water.
Why You Should Not Drink Untreated Water from Lakes and Streams
Clear mountain water can look pristine, but appearance is not a reliable indicator of safety. The CDC states that water containing germs that can make you sick, including bacteria, viruses, and parasites, sometimes looks perfectly clean. Drinking straight from a stream is generally not safe. The USDA Food Safety and Inspection Service (FSIS) says it is not a good idea to depend on fresh water from a lake or stream for drinking, meal preparation, or cleaning, no matter how clean it appears.
Germs from human or animal poop can wash into lakes, rivers, and streams. You can get sick by swallowing untreated water when you drink, cook, wash fruits and vegetables, make ice or drinks, or even brush your teeth. The CDC lists common symptoms as diarrhea, vomiting, and stomach pain. Backcountry travelers should always assume surface water needs treatment before it is safe to consume.
How to Treat Water in the Backcountry
The CDC describes several proven ways to remove germs from water while hiking, camping, or traveling. The CDC calls boiling the most effective way to kill germs, with filtering followed by disinfecting as the next option. The table below summarizes what each method removes and its key limitations, based on CDC guidance.
| Method | What it removes | Limitations |
|---|---|---|
| Boiling | Kills all viruses, bacteria, and parasites (including Cryptosporidium and Giardia) | Water must reach a rolling boil for 1 minute (3 minutes above 6,500 feet); allow to cool before use |
| Filtration (absolute pore size ≤ 0.3 micron) | Removes bacteria and parasites; does not remove viruses | Check the filter label for NSF standards 53 or 58 for cyst reduction; most portable filters do not remove viruses |
| Chemical disinfection (chlorine bleach, iodine, chlorine dioxide tablets) | Kills viruses and bacteria; may not kill parasites. Chlorine dioxide tablets can kill Giardia and are somewhat effective against Cryptosporidium | Filter water before disinfecting; iodine should be avoided by pregnant women, people with thyroid problems, and anyone with iodine hypersensitivity, and should not be used for more than a few weeks at a time |
| UV light (portable units) | Kills parasites, bacteria, and viruses in small amounts of clear water | Cloudy water shields germs from the light; always filter water before using UV treatment |
| Reverse osmosis filters | Removes parasites, bacteria, and viruses; also removes salt | Check the product instructions |
To boil water safely, the CDC says to bring clear water to a rolling boil for 1 minute, or for 3 minutes at elevations above 6,500 feet. Let the water cool before handling to avoid burns. When electricity is available, a small heating coil or beverage warmer can boil water conveniently.
Filtration relies on pore size. A filter with an absolute pore size of 1 micron or smaller, or one certified for NSF standards 53 or 58 for cyst reduction, will remove parasites but not viruses or all bacteria. To also remove bacteria, look for a filter with an absolute pore size of 0.3 micron or smaller. Reverse osmosis filters go further, removing viruses and salt as well.
Chemical disinfectants such as unscented household chlorine bleach, iodine, or chlorine dioxide tablets kill viruses and bacteria but may not kill tough parasites. The CDC stresses that filtering the water before adding a disinfectant is the safer approach. Chlorine dioxide tablets offer some protection against Giardia and partial protection against Cryptosporidium, but filtering first remains the safest practice. People who are pregnant, have thyroid issues, or have an iodine sensitivity should avoid water disinfected with iodine, and no one should drink iodine-treated water for more than a few weeks at a time.
UV light devices can kill all types of germs in small volumes of clear water, but suspended particles block the light. The CDC advises filtering water before treating it with UV light so the light can reach the germs effectively. MIOX systems, which use a salt solution to create a chlorine-based mix, kill viruses and bacteria but do not work well against parasites.
A critical warning from the CDC is that boiling or disinfecting does not remove harmful chemicals, toxins, or radioactive materials. If you suspect chemical contamination, use bottled water or a different source. Nothing you can do in the field will make chemically contaminated water safe.
Keeping Water Sources Clean: Bury Waste Away from Water
Human waste can contaminate the same water sources you rely on. The CDC recommends that in remote areas without toilets you bury your poop at least 8 inches deep and at least 200 feet away from lakes, rivers, and other natural waters. Bury waste downstream from where anyone collects water. Leave No Trace also advises digging catholes 6 to 8 inches deep and placing them at least 200 feet from water, camp, and trails, then covering and disguising the hole afterward.
Washing activities also need care. Leave No Trace suggests carrying water 200 feet away from streams or lakes before washing yourself or dishes, using small amounts of biodegradable soap, and scattering strained dishwater. Food scraps should be packed out, not left in the backcountry or burned. Leave No Trace adds that lotion, sunscreen, insect repellent and body oils can contaminate water sources where fresh water is scarce.
Hand hygiene matters, too. The CDC says to wash hands before handling food, before eating, and after using the toilet. When soap and water are not available, use a hand sanitizer that contains at least 60% alcohol. This simple habit helps stop germs from spreading to your water bottles, food, and mouth.
Frequently asked questions
How much water should I bring per person?
The National Park Service suggests drinking at least 2 liters of water a day, and more when you are in very hot climates. Plan additional water for cooking and cleaning. If you are car camping, large jugs and frozen water blocks give you a generous supply. Backpackers need to identify reliable water sources and carry treatment gear instead of hauling all their water.
Can I drink straight from a clear lake or stream?
No. The CDC warns that clear-looking water can still hold bacteria, viruses, and parasites that cause diarrhea, vomiting, and stomach pain. You should always boil, filter, or disinfect surface water before using it for drinking, cooking, or brushing your teeth.
Does boiling remove chemicals from water?
No. The CDC emphasizes that you cannot make water containing harmful chemicals, toxins, or radioactive materials safe by boiling or disinfecting it. If you suspect chemical contamination, seek bottled water or another safe source.
For more guidance on drinking water, visit the drinking water category page. You can also explore camping skills for tents, cooking, and organization, review essential camping skills for beginners, read hygiene and waste advice, and brush up on general camping safety before your trip.
