How does water get polluted?

Even though water is more precious than gold, a lot of our fresh water is being polluted with toxic chemicals or poisons that are being dumped and drained into our water systems. Some of these chemicals are common household items like chlorine bleach, paint thinner and the very poisonous mercury that comes out of broken thermometers. Other toxic chemicals that pollute our water include pesticides which are chemicals designed to kill insects, and petroleum products like gasoline and oil. Tons of these chemicals are dumped and washed into our water every year. This water pollution not only damages the animals, birds and fish that depend on clean, healthy water, but it is also harming our fresh water supply and making people sick.