http://pillars.ehshouston.org/science/ocean/handouts.htm

• Water is a compound consisting of two Hydrogen molecules bonded to one Oxygen molecule (H + OH = H 2 O)
• Approximately 70% of the Earth's surface is covered under water, that is approximately 326 million-trillion gallons of water
• About 98% of the water is found in our oceans which is undrinkable because of the salt content
• About 2% of our water is considered fresh water
• About 1.6% of Earth's water is in polar icecaps or glaciers
• An estimate of 0.36% of our water is underground in aquifers or wells
• Lakes and rivers contain around 0.036% of our water supply
• Approximately 65% of the human body is made up of water
• Water is essential to all life forms
• Water is an abundant renewable resource

http://www.rmi.org/sitepages/pid552.php