1. AIU Day 4. Water, Water, Everywhere!! Water Treatment in SW Pennsylvania

2. Drinking Water – SW PA

3. Where Does Pittsburgh Water Come From? Pittsburgh Water System –Allegheny River Roughly 70 million gallons of water are treated every day The plant is capable of producing over 100 million gallons per day. The treatment process takes three full days and consists of three separate stages

4. Stages of Drinking Water Processing 1.Clarification River water passes through a process called clarification, in which silts and clays are removed. This stage involves chemical formation of clumped particles called floc which are then physically removed by gravity sedimentation. 2.Filtration The clarified water next passes slowly through sand and gravel filters in order to remove fine particles and microorganisms 3.Disinfection The filtered water is finally treated with chlorine in order to ensure removal of any harmful microorganisms

5. What is to be Removed? Microbial contaminants ("Bugs") Salts and Metals Pesticides Herbicides Organics Radioactive contaminants

6. Instructions for coag and turbidity See the notes section for details on “cleaning” water using the coagulant and for measuring turbidity.