1. What is wastewater and why should we treat it (clean it)? Wastewater is a term that is used to describe waste material that includes sewage waste (poop, etc.) and industrial liquid waste that is collected in towns and urban areas It needs to be cleaned so that it does not pollute the environment!

2. 5 Steps of Treating Water Or, do we eventually drink the water that was previously flushed down the toilet?

3. 1 st : Preliminary Treatment Wastewater arrives at the treatment plant and goes through bar screens that take out large debris (like diapers, leaves, and trash)

4. Preliminary Treatment: This is a bar screen stopping large materials from going into the treatment plant

5. Preliminary Treatment Continued The large solid materials are collected for disposal (either in a landfill or an incinerator).

6. 2 nd : Primary Treatment The wastewater then flows to settling tanks where the bacteria settle out. Primary treatment might remove 90 percent of all solids and organic materials from the wastewater

7. 3 rd : Secondary Treatment This is where the suspended and dissolved materials not taken out by primary treatment are removed. This is where good bacteria eats the organic material and other solids before the water passes through membranes

8. 4 th -Disinfection Water passes through Ultraviolet (UV) light, a high energy part of the Electromagnetic (EM) Spectrum, that kills germs, bacteria, and viruses Chlorine added to the water kills any remaining bacteria, and the water is discharged

9. How water is cleaned up Disinfection is the most common form of drinking water treatment, considered by many to be one of the most important scientific advances of the 20th century. Most water suppliers add chlorine or another disinfectant to kill bacteria and other germs.

10. Chlorination Tank

11. 5 th Advanced Treatment Uses chemicals to remove phosphorous and nitrogen from the water. After this stage the treated water is released back into lakes, rivers, oceans, etc. Photo courtesy Falke Bruinsma Final clarifierFalke Bruinsma

14. Finally: What do we get from treating water Biosolids, from the solids (like poop) that go to the treatment plant, a nutrient-rich organic matter is produced, this can be used as a fertilizer or a bio-fuel. Reclaimed Water –This water is not clean enough to drink yet, there is another treatment process to make it potable! It is clean enough to go back into the water supply (a reservoir like a lake or river) Energy recovery –biofuels and biomatter, can be collected and used on-site in generators that produce electricity and for powering pumps. This means the poop going to the treatment plant can be burned to power the treatment plant!