Would You Drink That?
A microscopic photo shows unidentified microorganism, algae, protozoa and bacteria found in untreated water (left). An aerial view of a water treatment plant in South Dakota.Copyright Janice Haney Carr, Centers for Disease Control and Prevention, Department of Health and Human Services (left), South Dakota Department of Environment and Natural Resources (right) http://phil.cdc.gov/phil/details.asp http://denr.sd.gov/des/sw/MunicipalWastewaterTreatmentPlantAnatomy.aspx
This activity focuses on getting students to think about bacteria, water quality and water treatment processes. Students develop and test their hypotheses about the "cleanliness" of three water samples prepared by the teacher. Then they grow bacteria in Petri dishes from the water samples. They learn how private septic systems and community sewage and wastewater treatment plants work, the consequences to the surrounding environment and wildlife from human wastewater, and what measurements of the released "clean" water are monitored to minimize harm to receiving rivers and lakes.
Engineers are responsible for treating all of the water coming in and going out of our homes, schools and places of business every day—it's a process in which civil, environmental and chemical engineers are all involved. These engineers design small private septic systems and large urban water treatment plants and the processes employed to meet the crucial societal need for clean drinking water and wastewater disposal, while minimizing harm to the natural environment. Without water treatment local ecosystem would be completely changed. It is important for engineers to understand the delicate balance of an ecosystem so as not to destroy it.
After this activity, students should be able to:
- Correctly collect and plate a bacterial smear.
- Describe how wastewater is treated.
- Explain the importance of wastewater treatment.
- Describe the reasoning, thought process and requirements behind the design of wastewater treatment facilities.
- Explain environmental impact considerations associated with human wastewater treatment.
- Understand why each water treatment system is unique to each location.