Living in a modern industrial world, we tend to take water for granted. But we must not forget that it is the most essential component in long-term disaster survival.

What is a person to do if the public water supply goes down? The simple answer is clean your water or risk death.

There are a number of commercially available filters and chemicals to treat water, but in the long-term zombie apocalypse scenario you will need something you can make from commonly available materials.

To build a basic filter, all you need is some cotton fabric (T-shirts work well enough), a five-gallon bucket, some sand, gravel and crushed charcoal. Get the charcoal from your campfire, not from your grill. Commercially produced charcoal contains binding agents that are poisonous. You should also make sure the charcoal is about the size of your gravel: do not powderize it.

This article appears in its entirety in Zombie Apocalypse Monthly Issue 2 and can be downloaded for free here: http://www.magcloud.com/browse/issue/408784.