At the water treatment plant, waste water is left to sit in large storage areas until all of the solid waste settles to the bottom. The solid waste, now called 'sludge,' is slowly removed and usually burned or buried. The remaining water is then sent through a series of filters to remove harmful chemicals and bacteria. After all of these cleaning steps, the water is ready to pump back into rivers and lakes. To bring water from lakes and rivers into homes and businesses, water treatment plants often add chemicals to the water to kill bacteria.
Chlorine is one chemical used to purify water.
You've probably smelled chlorine before if you've been swimming in a public swimming pool. Another common chemical added to water is fluoride. Fluoride helps teeth grow strong, and you can also find it in toothpaste. To get water into your home, communities use large pumps to push the water up a tall water tower, where the force of gravity can create water pressure. Water pressure is important for our faucets and showers to work.