Quick Answer
Drinking rainwater in the wilderness can be safe if properly treated, but it may contain contaminants and bacteria that can cause illness.
Assessing Rainwater Quality
When assessing rainwater quality, look for signs of contamination such as animal or human waste, nearby pollution sources, or standing water. If the water has been exposed to these factors, it’s best to find an alternative source. In general, the fresher the rainwater, the safer it is to drink.
Treatment and Purification Options
There are several methods to treat and purify rainwater, including boiling, disinfecting with bleach or iodine, and using water filters or purification tablets. Boiling rainwater is the most effective method to kill bacteria and viruses, requiring a rolling boil for 1 minute at an elevation of 5,000 feet or less. If you don’t have a means to boil water, use 2 drops of unscented bleach per liter of water, or 5 milliliters of 2% tetrachloroethylene (TCEP) per liter of water. Wait for 30 minutes before consumption.
Finding and Collecting Rainwater
To collect rainwater, look for a spot with a slight depression, or create a shallow pit using rocks and branches. Use a tarp or plastic sheet to direct rainwater into the collection area. Ensure the tarp is securely fastened to prevent it from blowing away. The larger the collection area, the more water you’ll collect, so aim for a minimum of 1 square meter per person.
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