Treating Water in the Backcountry: How to Collect and Treat It

how to filter water in the backcountry

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Written by: Derek Vitiello
Fact Checked by: Ashley Vitiello

Updated Apr 22, 2023

Water is one of the most important resources you need to survive when you are backpacking or hiking in the wilderness. It’s also one of the scariest, because how do you know if it’s safe to drink? But don’t worry! This blog post will teach you how to get water, how to store it, and how to treat it so that you can enjoy your time outside without worrying about getting sick. We’ll go into detail on the primary types of pathogens found in water sources, how they affect your health and what precautions should be taken against them.

Gathering Water in the Backcountry

When you are gathering water from a natural source, it’s important to use proper techniques so that you don’t contaminate the water or make yourself sick.

Here are some tips for how to collect water in the backcountry:

– Always sanitize your hands frequently, before collecting water, and every time you answer the call of nature. In reality, many illnesses related to bad drinking water are actually more likely due to poor hygiene. 

Use a water filter to purify the water before drinking or cooking with it. This can remove most biological threats present in water sources like bacteria or protozoa. When using filters always make sure to follow the manufacturer’s instructions for how to do so.

– Filter the water into clean container. If there is any visible dirt or sediment on the bottom of the container, don’t use it since this will be introduced into your drink and could make you sick.

Boil water for a minimum of one minute (or for three minutes about 6,500 feet) if you are unsure about its safety. This is an effective method of killing pathogens and making water safe to drink.

– If clear water isn’t available, and you’re stuck with silty water, you can use a pot to scoop water from the cleanest water you can locate, then let it sit. The sediment will sink to the bottom, making it easier to filter. You can also use a pre-filter or strain the water through a bandana or thin clothing item before filtering. 

Tip: always carry a back-up water filtration or treatment option. You don’t want to get stuck out there without a way to filter water if your main device breaks. 

Best Water Sources to Use While Hiking or Backpacking

The best water sources to use when hiking or backpacking are those that are moving, as these will be less likely to contain harmful pathogens. Rivers, streams, and creeks all fall into this category, and they can be easily accessed in most parts of the country. Another good option is springs, which often have cool, clear water coming out of the ground.

If you don’t have a flowing water source available you can source water from a calm lake or pond, but make sure it doesn’t have a lot of sediment or silt. Clean water passes through your water filter more easily and isn’t as susceptible to clogging. Try to reach as far from the shore as possible, as this more shallow area is where those microorganisms are more likely to accumulate. 

Tip: If you are hiking in the rain, wait before gathering more water. When streams and rivers rise due to rain, they collect more sediment and the water is harder to filter. The increased flow also raises bacteria loads and it isn’t as safe. 

Signs That a Water Source Could be Contaminated

The following circumstances suggest that water from a particular source might be contaminated:

If you see dead animals, human waste, animal feces, or trash in the area. The presence of these things may indicate that there are disease-causing bacteria present. Also look for excessive amounts of foam or brown scum, as these can indicate an algae bloom.

Make sure not to collect water near established campsites or heavily used areas. Humans can introduce harmful pathogens into your clean drinking water if they don’t correctly follow the 7 principles of Leave No Trace. Avoid streams directly next to roadsides that have heavy traffic and people living near them. The water may be contaminated by runoff from their yards or waste materials dumped in the area, especially if there was a rain storm recently.

If you are hiking in an extremely dry climate where all of the streams may disappear, don’t rely on those as your source of drinking water! Even areas that aren’t that dry, such as high alpine environments, can run dry during the summer season or in between rains. It’s imperative that you properly research the exact route you’re taking and look at personal accounts of other hikers to see if the streams could possibly be dry. 

Most Common Waterborne Pathogens

Many different types of waterborne pathogens can make you sick, but some are more common than others. Even after as few as 10 disease-causing germs are consumed, symptoms including diarrhea and dehydration can occur.

  • Viruses like Hepatitis A, Norovirus, and Rotavirus. Since they are some of the smallest of the dangerous pathogens found in your water they are the most difficult to filter out of water.
  • Bacteria like Salmonella and E. Coli are some of the most common threats, as they can be found in both surface water and groundwater. Since these bacteria are a more medium-sized organism, they are much easier to remove from your water using a simple water filter.
  • Protozoa like Giardia and Cryptosporidium are also commonly encountered but are easily filtered out of water due to their large size.


Research is the key when it comes to making sure you will have clean drinking water options along your backpacking route. Always take into account season and that year’s rain totals, as well as the accounts of other hikers who have recently completed the route. Find the cleanest water possible before filtering, and keep an eye on your surroundings for signs the water could be contaminated. Use a filter properly, and you’ll be golden!


How do you purify water in the wilderness?

The best way to purify water in the wilderness is to use a filtration system or pump. If that’s not available, you can boil water for one minute (or three minutes above 6,500 feet), or use purification drops and tablets. 

How do you drink water in the backcountry?

Never drink water in the backcountry without first filtering it, treating it, or boiling it. Never assume that it’s safe to drink, no matter how clean it looks. 

How can you tell if water is safe to drink in the wild?

Never assume that any water in the backcountry is safe to drink without first filtering, treating, or boiling it. Don’t collect water from any sources that may be contaminated, such as water near popular campsites, roadways, pasture animals, dead animals, or feces. 

Does boiling river water make it safe?

Boiling water for at least one minute (or three minutes over 6,500 feet) is a great way to kill pretty much anything dangerous in the water. To be extra safe, try to collect the water from clear, moving water such as a stream or waterfall. 

Derek, Co-Founder at Know Nothing Nomads

My goal with my writing and Know Nothing Nomads as a whole is to share my passions of hiking, camping, and a love of the outdoors with our readers. Making the difficult and uncertain feel more approachable to people that might not know enough to feel comfortable taking their first steps into the wilderness is a driving factor for me. When I’m not writing you can find me on a trail, in a forest, or next to a river with hiking shoes on my feet and a fly rod somewhere close by.

Ashley is an adventurous soul who loves all things nature, especially warm sunshine, wildflowers, scenic snacking, and mushrooms. She is an avid outdoor enthusiast who has spent years enjoying time outside doing things like hiking, camping, and rock climbing.
Her goal with Know Nothing Nomads is to make these hobbies easily accessible through knowledgeable content and how-to’s based on all the stuff she’s learned on her journey. If she isn’t writing an article, she’s probably in a forest looking at big mountain views and tiny pieces of moss on the side of the trail.

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