Background
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Name _________________________ Per _____

Take a virtual tour of the Central Marin Sanitation Agency. http://www.cmsa.us/tour/virtualtour/
Background Reading Questions- Complete before the tour
Use your textbook and other references to answer the questions below.
1.
Define the following terms:
 Oxygen demanding waste (B.O.D.)–
 Clean Water Act
 Discharge trading policy –
 Septic tank -
2.
Describe each of the following:
 Primary Sewage Treatment –
 Secondary Sewage Treatment –
 Advanced Sewage Treatment –
3.
Describe a combined sewer system.
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Analysis Questions
Using the Background information from this activity, the Environmental Science text information from your tour to answer the following questions using complete sentences.
1.
Explain why it is important to remove nitrogen and phosphorus from raw sewage. Describe the relationship between these compounds and B.O.D.. Discuss where the nitrogen and phosphorus come from in Marin County.
2.
Discuss the advantages and disadvantages of a combined sewer system.
3.
Describe how our community may improve the wastewater treatment process.
4.
What should be done with sewage sludge? Discuss the advantages and disadvantages of using sludge from wastewater for fertilizer.
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5.
How is wastewater tested before being released back into the environment?
6.
List some of the items you were able to recognize in the primary treatment process.
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