1. Wastewater Treatment

2. Collection Sewers Collect wastewater and bring it to the wastewater treatment plant – Combined sewer overflows: Take untreated sewage and storm water to rivers, lakes and Puget sound during heavy rain events

3. Preliminary Treatment – Bar Screen: located at the beginning of the wastewater treatment plant to remove large debris – Influent pumps: transport incoming waste to the treatment plant

4. Primary Treatment – Sedimentation Tank: Remove solids that are heavy and sink to the bottom as well as oil and grease that floats to the surface. Primary sludge goes through solids treatment process and liquids do through a different process

5. Secondary Wastewater Treatment – Aeration tank: Wastewater from the settling tanks flows into the aeration tank, where microorganisms such as bacteria and protozoa eat material and nutrients, turning organic materials into solids – Clarifying tank: Solid matter settle and are pumped to solids treatment process or recycled back to aeration tank.

6. Final Treatment – Chlorination and contact tank: kill bateria and viruses – Dechlorination: Remove toxic chlorine from effluent

7. Water Released to Puget Sound – Effluent Pump: Transports effluent out to the environment