Explain why stormwater pipes are designed to have a velocity between 3 ft/s and 10 ft/s.

ENVIROMENTAL TECHNOLGY

Question 1 – 500 Words

1. Write an essay consisting of at least 500 words addressing ALL of the following topics (a. through g.):

1. 1. If the rainfall intensity is 2.5 inch/hour, watershed area is 8 acres, and rational runoff coefficient is 0.6, compute the peak runoff rate in ft3/s. Use the rational formula.
   2. Explain the concept of time of concentration.
   3. Why would someone want to use the SCS TR 55 graphical method instead of the simpler rational formula for determining peak rate of runoff?
   4. Explain why stormwater pipes are designed to have a velocity between 3 ft/s and 10 ft/s.
   5. Why does land development typically increase the peak runoff rate? What are some methods used to mitigate the increased runoff rate?
   6. Discuss some best management practices (BMPs) for stormwater quality control?
   7. How does the National Flood Insurance Program (NFIP) affect development in flood prone areas? In your response, include discussion of the base flood level.

You are required to use at least your textbook as source material for your response. All sources used, including the textbook, must be referenced; paraphrased and quoted material must have accompanying citations.

Question 2 – 500 Words

1. Write an essay consisting of at least 500 words addressing ALL of the following topics (a. through h.):

1. 1. Describe U.S. federal legislation regarding wastewater treatment and disposal.
   2. If 220 mg/L (milligram per liter) of BOD5 enters a wastewater treatment plant at a flow of 18 mgd (million gallons per day), how many pounds of BOD5 enter the plant each day?
   3. Explain the purpose and operation of a comminutor.
   4. What is the purpose of recirculation in a trickling filter?
   5. If the wastewater flow is 5 ML/day (million liters per day), MLSS is 1800 mg/L, BOD5 entering the aeration tank is 130 mg/L, and aeration tank volume is 1.5 ML (million liters), what is the F/M ratio in the tank?
   6. Describe the extended aeration process. When is it used?
   7. What are the pros and cons of wastewater treatment ponds?
   8. Discuss one alternative treatment technology for wastewater treatment beginning on page 264 of our textbook.