How To Purify Water If You’re Lost In The Wilderness
When you're stuck in the wilderness without clean water, your survival depends on knowing how to make the water you find safe to drink. Even crystal-clear streams can carry harmful bacteria or parasites. Learning a few simple methods for filtering water safely can help prevent serious illness and keep you strong enough to find your way out. Here are seven ways to purify water if you're ever lost in the wild, plus some key tips to keep in mind.
Boiling
If you can start a fire and have something heatproof to boil water in, this is the safest method for making water safe to drink. Bring the water to a rolling boil for at least one full minute. At higher altitudes, go for three minutes. Boiling kills bacteria, viruses, and parasites. It's reliable and effective, though it won't remove chemicals or heavy metals. If the source water looks cloudy, let sediment settle first or strain it through cloth before boiling.
Solar Still
A solar still uses the sun's heat to pull clean water from soil or plants. Dig a shallow hole, place a container in the center, and cover the hole with clear plastic sheeting. Weight the plastic’s center so the condensation that then builds up drips into your container. It’s slow, but it works. Use this method if you can’t find a direct water source, or to stretch your clean water supply further.
Purification Tablets
Water purification tablets are small, light, and easy to carry, using iodine or chlorine to kill germs. Follow the instructions carefully when you use them. Wait times vary, but are usually around 30 minutes. The water may taste odd after, but it's safer to drink. These tablets don’t remove dirt or chemicals, so use them after filtering if the water looks overtly dirty. If you hike often, keeping a few tablets in your kit is a smart move.
Charcoal Filter
Even if you don't have commercial charcoal, burned wood from a campfire can be crushed and used in a makeshift filter. Wrap it in cloth or layer it with sand and gravel in a bottle, then use that bottle to filter water into another container. This helps absorb some toxins and can even improve the taste. Like other filters, it won’t kill germs on its own. Always boil or treat the filtered water before drinking. It’s a good solution if you’re stuck with only dirty water around.
Sunlight Disinfection
If you have clear plastic bottles and full sun, you can use UV rays to disinfect water. Fill a bottle and lay it on its side in direct sunlight for at least six hours. If the sky is cloudy, double the time. The sun's UV rays kill many bacteria and viruses. This only works in clear bottles with clear water, and won’t help against some parasites. Still, it’s a decent backup when you have few options.
Avoid Risky Water Sources
Though knowing how to purify water is helpful, it's also good to know what water you shouldn't even attempt to purify anyway. Avoid any water that smells bad, has dead animals nearby, or comes from stagnant puddles. Fast-moving water is way, way better than still. Try to collect rainwater if possible, or melt clean snow or ice. If you're unsure about a water source and have no way to treat it, it’s sometimes safer to go without for a short time than to drink something risky.
When you're lost and low on supplies, every decision matters. Water is a top priority, but drinking unsafe water can make an already bad situation worse. However, knowing a few basic techniques can give you better odds. Some are fast, some take time, but all are worth knowing. Try to practice these methods before you actively need them. The more prepared you are, the calmer you’ll be if the time ever comes. Your safety may depend on it.