Get access to everything we publish when you sign up for Outside+.
»Scout for a clearer source. Good bets include: pond inlets, rocky streams, and headwaters—such as where water springs from the ground or runs from a snowfield. Turbid water is more likely after floods, forest fires, and spring runoff, or downstream of canyons, deserts, and moraines.
»Strain the silt. In a hurry? “Cover your bottle’s mouth with a coffee filter, bandana, sock, or shirt, fill it with water, then pump or treat the bottled water,” says Erik Kulick, founder of True North Wilderness Survival School in Pennsylvania.
»Let it settle. If you can wait a while, let the water sit in your cookpot overnight (cover it to keep critters out), then carefully ladle the top, clear layer into another container and pump it or use a UV device or chemical treatment.
»Set up a capillary filter. If you’re short on water but long on time, dip one tip of a wet bandanna into an elevated bottle containing the murky water, then put the other tip into an empty bottle situated below the first one. Clean water will be wicked along the fabric and drip into your container. Caveat: It takes about an hour to filter one cup, and you still have to treat it.
»Boil for one minute. Though boiling burns time and fuel, it packs a double punch: The heat kills pathogens, and the boiling action settles sediment. Extract the clear layer when done.