污水下水道系統為目前國內積極推動之公共建設，係因其對民眾生活環境之改善，國家競爭力之提昇，均有重大幫助。而依促參法規定污水下水道工程屬於重大公共建設，為紓解政府短期財政負擔及引進民間機構之資金、活力與管理績效，故行政院推動促進民間參與污水下水道建設計畫，將平均日污水處理量超過一萬噸之系統，以BOT模式推動，總計國內有三十六個系統。 本研究以『羅東地區污水下水道系統』建設案為例，針對污水下水道BOT(Build-Operate-Transfer)投資案進行財務分析，透過淨現值、內部報酬率、回收年限、自償率及分年償債比率等指標，評估可行之結果。本研究發現，若污水處理系統全由民間興建營運，則污水處理費率須達33.77元/度，民間機構之投資可達到完全自償，權益報酬率為10%，且就政府角度來看之計畫報酬達7.61%，才會使BOT計畫案具財務上之可行性。 但由於污水處理費費率相對遠高於現行自來水價，故台灣之污水下水道系統建設若以BOT模式推動，會產生(1)大幅加重用戶負擔(2)民間機構收費不易等缺失。同時從財務試算中得知，民間機構須做好建設時程控管並密切掌握用戶接管進度，才能有效提昇其投資報酬率。 The sewage system is the important public infrastructure actively implemented by the central government now, since it can furthermore improve our environmental quality and promote the nation’s competitiveness. To minimize the government’s short-term financial burdens and attract the private investment, vigor, and efficient management, the Executive Yuan encourages the private sector to participate the sewage system construction plans via the BOT (Build-Operate-Transfer) model for those systems over 10,000 tons capability per day. According to the official statistics, there are such totally more than 36 systems in the country. This research is based on the case of” Lotong District Sewerage System”, which focuses on financial analysis of BOT investment projects of sewage sewers by net present value (NPV), internal rate of return (IRR), payback year, self-liquidation ratio (SLR) and debt service coverage ratio (DSCR) to evaluate the financial feasibility. This research finds that to meet the financial feasibility of the project for the private sector, the sewage purification fare should be above 33.77 NTD/unit so as to have equity IRR 10% and project IRR 7.61%. Due to the calculated sewage purification fare far above the current water fare, it will lead to some burdens of users, inconvenience of fare collection by private investor institutions, and some other deficiency. Based on the financial calculation and analysis, it concludes that the investment required return could be enhanced by monitoring of the construction status and considerate control for the construction of house connection for sewage.
