How to Purify Water for Survival

Never drink unpurified water from an outdoor water source.

When you are fighting for survival, securing a safe source of drinking water is crucial. Yet, locating a running creek or stream doesn't mean that the water within it is safe to drink. Be cautious before drinking from any outside water source and purify it to protect yourself from becoming ill from any organisms that may be lurking in the liquid.

Things You'll Need

• Container
• Dry timber
• Rocks
• Source of ignition
• Tongs or sticks
• Plastic bottle or can
• Knife

Instructions

Boiling Water Over Fire

1. Dip a container in a water source to gather water for boiling.

2. Arrange stones in a circle to create a contained area in which to build a fire. Stack dry timber and ignite. Place the fireproof container on top of the fire and allow it to come to a boil.

3. Boil the water for at least one minute or up to three minutes to ensure that all harmful organisms are killed. Allow the water to cool before drinking.

Rock Boiling for Containers That Aren't Fireproof

1. Build a fire in a contained area, such as within a ring of rocks. Ignite the fire with whatever you have available.

2. Locate rocks that are about the size of a silver dollar. Dust them off or wash them in a water source to remove dirt. Collect water from the water source in a container and set aside.

3. Place the rocks into a hot fire for 10 to 15 minutes. Remove the rocks from the fire with tongs or with two sticks fashioned to act as tongs. Find two sticks with curved or forked ends and use them to pick up the rocks.

4. Place the rocks in the container filled with water. The heat from the rocks will transfer to the water. Continue adding rocks to the water to make the water boil. Boil the water for one to three minutes. The longer you boil the water, the better the chances that you will kill all of the organisms.

5. Allow the water to cool and remove the rocks from the water before drinking.

Filtering

1. Punch five to 10 holes in the bottom of a plastic bottle or a can with a knife. Cut the neck off the plastic bottle with the knife so that you can construct the filter more easily.

2. Put a 2-inch layer of pebbles in the bottom of the can or container to prevent finer filter material, such as sand, from escaping.

3. Place an even layer of grass on top of the pebbles, followed by a layer of sand about 1 inch thick. Continue layering 1-inch thicknesses of pebbles, grass and sand until you completely fill the container.

4. Collect water from an available water source in another container. Avoid stagnant marsh or pond water for use with this filter because it cannot effectively kill off harmful bacteria.

5. Pour the collected water into the homemade water filter and catch the water in another container as it drains out of the bottom of the filter. Check to see if the water is clear. If not, filter it again by pouring it back through the filter container and catching it at the bottom as it drains out.

Tips & Warnings

• If you are in a situation where you have access to electric heat, substitute the electric heat for the fire.

• When you boil water, the water should have a large amount of bubbles throughout the water which constitutes a rolling boil.

• If you have access to charcoal, layer charcoal with your sand and grass. The charcoal will help eliminate bacteria.

• Homemade water filters are best used for rainwater that has collected in a puddle, not for water from streams, creeks or rivers. This is because this type of filter will not effectively remove bacteria or organisms. It will only filter particles.

References

• Wildwood Survival: Water Purification
• Wilderness Survival Skills: How to Make a Water Filter in the Wilderness