How to Build a Water Purification Still

You can make contaminated water safe to drink.

Your water may be contaminated for a variety of reasons, including loss of pressure in your municipal system (or maybe you are camping in a remote area and only have access to lake or river water). Unfortunately, after a natural disaster such as a hurricane, earthquake or flood, there may be no gas or electricity to boil water for sterilization. Regardless of your situation, a simple solar still will purify small amounts of clean drinkable water from whatever water source is at hand.

Things You'll Need

• Bucket or other large container
• Small container
• Unpurified water
• Food-grade plastic wrap
• Rubber band big enough to fit around the top of the larger container
• Small rock or some coins

Instructions

1. Pour some contaminated water into the bottom of the larger container. A container that is wider than it is tall will produce clean water at a faster rate, but any container will work.

2. Place the smaller container inside the larger one. Make sure it is exactly in the center and that the water is not deeper than the small container. If there is too much water in the large container, pour some out.

3. Cut a piece of plastic to completely cover the top of the larger container and secure it with a rubber band.

4. Place a small pebble, a few coins, some car keys or a similar weighted object in the center of the plastic, directly over the small container. The plastic should sag enough that condensation on the underside runs down the plastic and drips into the small container.

5. Place the bucket in the sun. As the water inside heats and evaporates, it will condense on the underside of the plastic and slowly fill the small container with purified water. When the small container is nearly full, remove it and store for drinking.

References

• PBS Kids: Solar Still