The Northeast’s forests and mountains are home to an abundance of pristine-looking lakes, ponds, rivers, streams, and brooks. Although thirsty backcountry travelers will find these bodies of water inviting, there’s no guarantee that the water they contain is safe to drink. A water filter, a water purifier, a chemical water treatment, and boiling water can all make water found in the backcountry potable, but each has its pros and cons, begging the question: which water treatment option is right for me?

There are four main types of ways to make water potable in the backcountry: boiling it, treating it with a chemical (like iodine or chlorine), filtering it, or using a water purifier.

Credit: Tim Peck


Boiling is the longest-standing way for making water potable. Just pour the water into a pot, heat until it is boiling, and then maintain a rolling boil for at least one minute (three or more at higher altitudes). Boiling is the most effective treatment option, killing bacteria, viruses, and parasites.

Pros of Boiling Water

  • Most effective
  • Great option for when you need to turn snow or ice into drinkable water.

Cons of Boiling Water

  • Requires a stove and pot
  • Time-consuming, uses a considerable amount of fuel, and eliminates those refreshing sips of cool mountain water
  • May want a secondary filter to clear out dirt and particulates

Chemical Treatment

Chemical water treatments, also known as disinfectants, are a tried-and-true method for ensuring safe drinking water in the backcountry or while traveling as they’re effective against bacteria, viruses, and some parasites. Most chemical water treatments are typically iodine- or chlorine-based.

Pros of Chemical Treatments 

  • Easy to use
  • Super-small, ultra-light, and extremely packable
  • Kills viruses
  • Inexpensive

Cons of Chemical Treatments 

  • It can take a long time to treat water
  • Often leave a chemical taste behind
  • Won’t remove particulates like dirt and sediment
  • Chemicals are consumable and require replacement
  • Not effective against all protozoa

Thanks to their small size and negligible weight, chemical treatments are a good partner on ultralight missions where keeping pack weight and size down is a priority. Chemical treatments are also an excellent backup water treatment option, as they don’t have any moving pieces or filters that can fail. Add a few tablets to your first-aid kit, just in case.

Water Filters vs. Water Purifiers

If you’re going to need a lot of water to drink on your trip, you’ll likely want a water filter or purifier. They each work a little differently.

Water filters work by straining out unwanted material like protozoa and bacteria based on size. This makes them particularly effective for treating water-borne pathogens commonly found in the U.S. and Canada—like Giardia, E. coli, and Salmonella. Water purifiers eliminate bacteria and protozoa while also providing protection against viruses—which are too small for a filter to trap—like hepatitis A, rotavirus, and norovirus which are often found in water when traveling abroad, especially in less developed countries.

Different Types of Water Filter and Purifiers

There are numerous systems available for filtering and purifying water in the backcountry, each with its advantages and drawbacks, and ultimately best suited to certain situations.

Pump Filters and Purifiers

Pump filters and purifiers are popular methods for treating water in the backcountry. As their name suggests, they work by pumping water through a filter or purifier using good old-fashioned elbow grease.

Pros of Pump Filters

  • Can pull water from the shallowest seeps, springs, and puddles
  • Removes sediment and other detritus
  • Allows you to filter the exact amount of water needed with a pump
  • Fast (provided you’re fast at pumping)
  • Versatile and works well for everything from solo to group trips

Cons of Pump Filters

  • Pumping is a chore, especially at the end of a long day or when treating a large quantity of water
  • More moving pieces than other water treatment options, which increases the likelihood of equipment failure
  • Heavier and less packable than other water filtration/purification systems
  • Requires regular maintenance and cartridge replacement
  • The various chambers and hoses found on pumps have a way of holding onto water which can empty into your pack when it’s put away

Pump filters and purifiers are a common sight in the backcountry because of their versatility. They’re equally adept at pulling water from shallow trickles and deep lakes and work great for everyone from the solo backpacker looking to fill one or two Nalgene bottles to big groups with a lot of collective pumping muscle.

Credit: Tim Peck

Gravity Filters and Purifiers

Aptly named, gravity filters let gravity do the work of pushing water through a filter, rather than relying on the physical effort of pumping.

Pros of Gravity Filters and Purifiers 

  • Set it and forget it—once configured, gravity does all the work
  • Adept at filtering large quantities of water, making them ideal for large groups
  • Once set up, gravity filters are one of the fastest water treatment systems
  • Typically consist of a combination of bladders and hoses, which are extremely packable and easy to split up among a group

Cons of Gravity Filters and Purifiers 

  • Finding a place to hang a gravity filter/purifier is at times a challenge, like when traveling above treeline
  • Sometimes difficult to use with shallow water sources
  • Setting up is often time-consuming—they’re comparatively cumbersome and consist of a fair number of pieces
  • You may need to keep track of the “clean” and “dirty” bladders

Gravity filters excel when used for large groups on trips with an abundance of available water (group backpacking trips with camps near lakes, ponds, or rivers, for example). They’re also ideal for canoe and kayak trips, such as overnighting on the Seven Carries Canoe Route.

Ultraviolet (UV) Light Purifiers

UV light purifiers offer a high-tech way to treat water by using ultraviolet light to naturalize pathogens—the high-intensity light disrupts the DNA of bacteria, protozoa, and viruses, ultimately rendering them harmless and water potable.

Pros of UV Light Purifiers 

  • Quick and easy to use
  • No filter element to clean or replace
  • Kills viruses, which makes them ideal for international trips
  • Lightweight and packable

Cons of UV Light Purifiers 

  • Backcountry users will need to keep track of battery life and likely carry backup batteries
  • The batteries themselves may be specialized and it can be hard to find a replacement
  • Make the water safe to drink, but not always desirable to drink since they don’t remove dirt, debris, or sediment
  • Treating large volumes of water is slow compared to other options

UV light filters are best suited to trips in which there is access to running water free of sediment but the quality of water is in question, such as treating water while traveling internationally.

Bottle Filters and Purifiers

Bottle filters and purifiers have built-in elements to treat water as you drink, making them super simple and convenient to use.

Pros of Bottle Filters and Purifiers 

  • Offers a simple, easy, and intuitive option for treating water
  • Lightweight, packable, and more functional alternative to traditional water bottles

Cons of Bottle Filters and Purifiers 

  • Not a great option for groups—the quantity of water treated is limited to the size of the bottle

Bottle filters and purifiers are ideal for solo missions and backpacking trips where water is plentiful and everyone is responsible for treating their own water.

Micro- and Straw-Style Filters

Super packable and lightweight, micro- and straw-style filters allow you to safely slurp water from the source.

Pros of Micro- and Straw-Style Filters 

  • Inexpensive
  • Easy to use—simply dip into a water source and suck
  • Lightweight and packable

Cons of Micro- and Straw-Style Filters 

  • Water is only available at a water source since there is no container
  • Ideally used as a water treatment option for just one person

Lightweight and cost-friendly, micro- and straw-style filters are good for users who will always remain in proximity to a water source. They also offer an affordable and super-stashable backup option to other water treatment systems.

Something to Sip On

There are a lot of water treatment options available to backcountry users these days. While every water treatment method will work, the conditions of your trip(s) will mean that some methods work better than others. When considering a water treatment system, ask yourself these questions to help find the right water treatment option for you:

  • Where will you travel?
  • How many people will you travel with?
  • What do your water sources look like?
  • How much pack space do you have?
  • What is your budget?