1. Operation Water Biology
Chlorination and Dechlorination

2. 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.

3. Guidelines in Canada Guidelines for: No 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.

4. 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