System Description: For this assignment, you will be assessing life cycle costs (including construction and energy costs) associated with a rainwater harvesting system. The rainwater is collected from rooftops, stored, and then used for toilet flushing. The storage tank can hold 3,500 gallons of water. Additionally, the system contains a pump that can refill the storage tank from the regular water supply in cases when there is not enough rainwater collected to meet the toilet flushing demand. The costs for the system are as follows: Construction Costs: Storage tanks $970 Catchment gutters $350 Fittings, valves, and pipe. $650 Pump $325 Labor $600 Energy Cost: Annual energy costs can be calculated from the following equation: C annual energy cost ($) C = p * Qht 0.7457 3956 Q flow rate (gpm) = 0.5 gpm h = total dynamic head of pump (ft) = 50 ft p = price of energy ($/kWh) - determine electricity price for Lexington, KY t duration that pump is operating = 2,000 hours per year e = efficiency (% as decimal) = 75% The following additional details for the rainwater harvesting system may be relevant: Assume a discount rate of 6%. . The lifetime of the system is 25 years. The rooftop area (from which water is collected) is approximately 5 acres. A storage tank can hold 3,500 gallons of water. Unit costs for this assignment are based on: Ghimire, S. R., Watkins Jr, D. W., & Li, K. (2012). Water Science and Technology: Water Supply, 12(3), 309-320. Assignment Directions: 1. Draw a cash flow diagram that describes the rainwater system. (5 points) 2. Calculate the total life cycle costs in terms of present worth. Show your work either in a document or in an attached spreadsheet. (40 points) 3. Describe the major contributor(s) to total life cycle costs. (5 points) 4. Choose an appropriate functional unit for the system. Justify your answer. Normalize total costs to your chosen functional unit. (20 points) 5. Based on the results, provide 2 specific ideas for bringing down total life cycle costs. Calculate the reduction of life cycle costs associated with your 2 ideas. (25 points) 6. Briefly describe additional decision-making criteria that might be relevant for the rainwater harvesting system and how that criteria could be incorporated. (5 points)