There is the same amount of water on Earth as there was when the Earth was formed. The water from your faucet could contain molecules that dinosaurs drank. Water is composed of two elements,Hydrogen and Oxygen.
Water regulates the Earth's temperature.
It also regulates the temperature of the human body, carries nutrients and oxygen to cells, cushions joints, protects organs and tissues, and removes wastes. A person can live about a month without food, but only about a week without water. Water is part of a deeply interconnected system. What we pour on the ground ends up in our water and what we discharge into the air eventually ends up in our water Setting standards for water quality is a complex process. It involves scientific research, analysis, evaluating health benefits and costs, and identifying appropriate treatment technologies.