PROBLEM :

You have been appointed as the responsible Manager of the Water and Sewerage Administration of a city with an existing population of 336,000. It is known that population increase rate is fixed and 2% /year. There is no wastewater treatment plant in your city. According to the legislation, you have to build and commission an appropriate wastewater treatment plant as soon as possible. The economic life time of the plant will be 20 years. The new plant will serve to the population of this time. There is a 20 hectares of private land which is proposed to be enough for the purpose, next to the river where the treated wastewater will be discharged. The sewerage network, which previously collected all the wastewater of the city, was built and wastewater has been brought up to this land. Your administration plans to meet 100% of the CAPEX required for the establishment of the facility by obtaining a loan from a bank. The most advantageous loan has a USD 10-year period with 2-year grace period (non-refundable period), with 8% annual interest rates.

1. Using this information, a) Please define what kind of works to be conducted during the preparation stages of this treatment plant and what the cost of each work would be. b) Define what kind of construction and installation works to be performed and roughly calculate the costs of each of them, from the start of the construction and installation scheme to the commissioning and start-up phase where the contractor will completely leave the site c) Define the types of operating and maintenance works and roughly calculate their costs in USD / year. You can predict that the facility will be operated by 20 years. Please show the results with tables and bar/pie diagrams accordingly.

2. You need to develop a full cost recovery based tariff system to ensure the sustainability of the plant using the initial investment (CAPEX) and operating/maintenance (OPEX) costs you found. a) Determine the basic principles (values) of this system. b) Identify the components of the full cost recovery based tariff system, calculate the annual costs for each component and determine the net total system cost. c) Determine the average tariff price (as USD/m3 wastewater to be treated). d) Determine the subscriber groups you will reflect the tariff and reflect the average tariff to each subscriber group with an excel table.

3. Briefly comment on what this assignment taught you.

Additional information:

- One person produces 200 liter/day.ca of wastewater.

- For a wastewater treatment plant with this capacity, roughly estimation of total CAPEX can be found with this unit price factor: USD 300 / m3 wastewater to be treated.

- Real estate price of site for that region: 10 USD/ m2