How to Purify Water in the Outdoors

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Proper hydration is critical in the outdoors. But water is heavy. Carrying enough water for a three-day trip without tapping an outdoor source, like a river or pond, can really weigh you down. On the other hand, the more we hear about these waterborne nasties like Giardia and Cryptosporidium, the warier we become.

So what's the best option? Understanding how to use outdoor water sources in a safe manner. It isn't difficult, but it does take some patience. We generally have three ways to make our drinking water safe: boiling, filtering and chemical. Let's take a quick look at each.


By bringing water to a rapid boil for ten minutes, you will successfully kill off any little critters in the H2O that would do you harm. It's a little more work than filtering, but requires no extra gear. If your food is coming by way of freeze dried dehydrated packets such as Mountain House or Backpackers Pantry, you're going to be boiling water anyway, so increase the amount for some surplus to drink later. Boiled water does tend to taste very flat, so freshen up the taste by stirring or shaking the water to get some oxygen back into it.


First of all, what is the difference between a filter and a purifier? A purifier takes filtering one step further and introduces a chemical component to kill off things like viruses that filters won't catch. It is generally agreed that this is an unnecessary component when staying in the US. Waterborne viruses are not something we have in our domestic water systems.

That being said, a filter/purifier is a fast and safe way to pump water out of a dirty, unfiltered source, into a clean container. Filters are nice because they are fast, allowing you to drink the water immediately once it's clean. This can be a very welcome thing on a hot day when boiling your water and waiting for it to cool can seem like an eternity. Filters have become much smaller, more effective and less expensive in the last ten years.


These will typically come in the form of iodine tablets. They're extremely effective when it comes to killing off those little bugs, and ultra small and lightweight, making them a popular choice. Newer tablets even include a second tablet to drastically reduce the chemical smell and taste the iodine can create. These tablets require a bit of patience as they need about 30 minutes to be totally effective.

In addition to these methods, there are a few things that can be done to make this process easier. Moving water is usually a better source than stationary, as it tends to remove the scummy top layer that can form on pond and pools. It is also still deemed a safe practice to drink water directly from a spring head. This is the place the spring first bubbles up from the ground. Drinking spring water even a few feet from its source is a dicey practice. It only takes a few feet to pick up something that will make you miserable for months.

A collapsible water bucket can also make life much easier on the trail. Fill it from your "dirty" source, and boil, filter, or chemically treat the water as needed as opposed to making a new trip to the water source each time. This also allows dirt and heavy particles to settle on the bottom so you don't need to deal with them as you treat your water.

Stay hydrated on the trail. Hiking is very strenuous and your body needs that water to keep things running smoothly. Headaches, muscle cramps and fatigue are all signs that your H2O tank is running low. Drink up and see if you don't feel a whole lot better.

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Fill up your water bottles at a campsite before hitting the trail.