A Guide to Drinking Water Treatment and Sanitation for Backcountry & Travel Use

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This document should only serve as a guide for individuals intending to use untreated or poorly treated water as a drinking source. This document may also aid travelers and backcountry water users in researching drinking water treatment methods. Except for boiling, few of the water treatment methods are 100% effective in removing all pathogens.

Things to Remember

Please remember that:

  • Boiling can be used as a pathogen reduction method that should kill all pathogens. Water should be brought to a rolling boil for 1 minute. At altitudes greater than 6,562 feet (greater than 2000 meters), you should boil water for 3 minutes.
  • Filtration can be used as a pathogen reduction method against most microorganisms, depending on the pore size of the filter, amount of the contaminant, particle size of the contaminant, and charge of the contaminant particle. Manufacturer’s instructions must be followed. More information on selecting an appropriate water filter can be found at https://www.cdc.gov/parasites/crypto/gen_info/filters.html. Only filters that contain a chemical disinfectant matrix will be effective against some viruses.
  • Disinfection can be used as a pathogen reduction method against microorganisms. However, contact time, disinfectant concentration, water temperature, water turbidity (cloudiness), water pH, and many other factors can impact the effectiveness of chemical disinfection. The length of time and concentration of disinfectant varies by manufacturer and effectiveness of pathogen reduction depends on the product. Depending on these factors, 100% effectiveness may not be achieved. Manufacturer’s instructions must be followed.
  • If boiling water is not possible, a combination of filtration and chemical disinfection is the most effective pathogen reduction method in drinking water for backcountry or travel use. Manufacturer’s instructions must be followed.

Other treatment methods can be effective against some of the above pathogens:

  • Ultraviolet Light (UV Light) can be used as a pathogen reduction method against some microorganisms. The technology requires effective prefiltering due to its dependence on low water turbidity (cloudiness), the correct power delivery, and correct contact times to achieve maximum pathogen reduction. UV might be an effective method in pathogen reduction in backcountry water; there is a lack of independent testing data available on specific systems. Manufacturer’s instructions must be followed.
  • MIOX® systems use a salt solution to create mixed oxidants, primarily chlorine. Chlorine has a low to moderate effectiveness in killing Giardia, and a high effectiveness in killing bacteria and viruses. Manufacturer’s instructions must be followed.

Important: Water that has been disinfected with iodine is NOT recommended for pregnant women, people with thyroid problems, those with known hypersensitivity to iodine, or continuous use for more than a few weeks at a time.

Keep germs out of water and off your hands

In addition to using the appropriate drinking water treatment methods listed above, take these steps to protect yourself and others from waterborne illness:

  • If you are in a remote area without toilets, bury human waste (poop) 8 inches deep and at least 200 feet away from lakes, rivers, and other natural waters. Make sure to bury poop downstream from where you or others collect water.
  • Wash your hands before handling food, eating, and after using the toilet. If soap and water are not readily available, use a hand sanitizer that contains at least 60% alcohol.
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