The process in a water treatment plant: Before water is purified, it is pumped through coarse screens made of metal bars that catches large objects like bottles and cans. The screened water is then forced into a mixing tank by the pumps. In the mixing tank, chemical called coagulants are mixed into the water. Sticky clumps called flocs, that are aluminum hydroxide, are formed when the coagulants combine with bacteria, mud, and silt. Coagulants such …showed first 75 words of 328 total…

…showed last 75 words of 328 total…supply. This is a controversial issue because adding fluoride has a good side as well as a bad one. Adding the right amount of chloride to the water supply is safe and it reduces dental decay in children by making tooth enamel more resistant to acid produced bacteria in the mouth - therefore stopping bacterial growth. The only drawback is that too much of fluoride causes mottling in the teeth - making it yellowish colour.