Operation Water

BiologyChlorination and Dechlorination

Treatment plant» What is the purpose of a water treatment plant?

˃ To remove all contaminants and make the water safe to drink

» What should be removed?˃ Bacteria, ammonia, phosphorus, nitrogen, dissolved organic material,

iron, arsenic, and more….

» The government sets out guidelines for contaminants and as long as the treatment plant removes enough, the water is safe to drink.

Guidelines in Canada» Guidelines for:

˃ Iron, arsenic, and nitrate – due to aesthetic or health effects on people who drink the water

» No guidelines for:˃ Ammonia & phosphorus – as they are not usually dangerous at levels

found in drinking water

» Safe Drinking Water Foundation suggests decreasing the allowable limits on contaminants that have guidelines & making guidelines for contaminants that do not have guidelines.

Chlorine» What do you think of when you hear that word?

˃ Usually we think of swimming pools

» What is the function of adding chlorine to pools?˃ Chlorine is used to disinfect water - in pools or for drinking!

» What does chlorine do to the water?˃ Kills microorganisms (bacteria & viruses)˃ Also reacts with and removes chemicals like ammonia˃ Produces small amounts of Chlorine Byproducts during disinfection