The final step of purification is disinfecting the water which can be done by either boiling or treating with a disinfectant. This is the most important step as these methods will kill any remaining organisms in the water, especially those that could make you sick.
Boiling:
Boiling is the best way to kill disease-causing organisms, including viruses, bacteria, and parasites. The high temperature and time spent boiling are very important to effectively kill the organisms in the water. Boiling will also effectively treat water if it is still cloudy or murky.
If you’re at an elevation below 6,500 feet, put the water in a container over a heat source, such as a campfire or propane stove, and bring to a rolling boil for 1 minute.
If you’re at an elevation over 6,500 feet, bring the water to a rolling boil for 3 minutes.
Your water is now ready for drinking! You can make tea or coffee if you like it hot. Let it cool down first before you put it into your container. Disinfection:
Disinfection happens when a chemical or UV light is added to water to kill bacteria, viruses, and other potentially harmful organisms. Many factors can impact the effectiveness of these methods including water temperature, pH, and cloudiness. With disinfectants, it is important to allow the chemical or UV light enough time to treat the water and kill the organisms before drinking – this is called contact time.
Chemical disinfection involves adding one or more chemicals to your filtered water that are effective at killing waterborne organisms.
Chemical tablets or liquid drops are the most common ways to disinfect natural water. Iodine or chlorine dioxide are the most frequently used disinfection agents. National Sanitation Foundation (NSF) approved products are recommended
Follow the manufacturer’s instruction for disinfecting the water. Contact time to disinfect the water varies by product (example: 30 minutes to 4 hours). If the water is cloudy or has floating debris, it will be more effective to pre-filter the water before disinfecting.
WARNING: Do not use pool-cleaning tablets to disinfect drinking water! Pool-cleaning tablets are not intended to be consumed.
WARNING: Consult with your physician before using any disinfection products. Some tablets or drops, especially iodine, may not be safe for pregnant women, people with thyroid issues or iodine hypersensitivities, or for user over long periods of time.
Visitors using UV purifiers to disinfect their water
NPS Photo
Portable battery-operated UV purifiers can be used to reduce bacteria, viruses and protozoa in water from natural sources. However, these purifiers are only effective in disinfecting small quantities of clear water, are battery dependent and require correct contact time with the water.
To achieve maximum disinfection, make sure you:
Pre-filter your water as small particles and sediment may shield microorganisms from the UV light.
Check that you have enough battery power. If the battery power falls below a certain level, it will not be able to safely disinfect water.
Make sure you allow for enough contact time with the water. Follow the manufacturer’s instructions because inadequate exposure to the UV light may fail to disinfect your water.
As an extra precaution: Add a small amount of your preferred chemical disinfectant to the water in your container to maintain water quality and reduce the growth of organisms in the container.
