Planet H2O

Bottled water is a $50 billion-a-year industry worldwide, and people in the United States consume more bottled water than people in any other country. How is it different from what comes out of our taps? Is it really tastier, fresher and healthier – or is that just the advertising hype? The quality of tap water varies depending on where you live, and you can check on the EPA’s Web site to find out if your community’s water meets national standards. For most of us in the United States, tap versus bottled water is a personal choice.

Seventy percent (70%) of the Earth’s surface is covered with water and when viewed from space, our planet appears blue with a plentiful supply of water. However, clean, fresh water for drinking and irrigation is a scarce and valuable commodity in many parts of the world. Even though water is abundant on our planet, only a very small percentage can be used by humans and other organisms. This activity demonstrates the sources of water on our planet. Reduce Earth’s water supply to 2 liters and then use common household items to represent the distribution of water on our planet. More than half a gallon is found in the oceans, inland seas, and salt lakes – water that is too salty to use. At the end of the activity, you will see that only about 1 teaspoon of our original 2 liters is readily available for human use – water that is found in rivers, lakes, streams, and underground aquifers.