This paper focuses on the initial assessment of wastewater treatment (WT) projects through Public Private Partnerships (PPPs). Due to the fact that the initial investment of a PPP-type WT project is too high and can be fi nanced by both the public and private sectors, crucial during the project's feasibility stage is to estimate the partners' funding rates. Herein, the fi nancial analysis that is included in the cost benefi t analysis methodology as well as the quantitative value for money assessment method are used, in order to introduce a new process that estimates the funding ratios of the partners. Specifi cally, the process calculates the upper and lower boundaries of the public and private sectors' funding ratios in the initial investment, which include all the funding scenarios that are profi table for both partners. It applies mostly in the WT projects that are considered to be implemented through the build-operate-transfer contract type, which is probably the most commonly used type in PPPs. The new process is used in a WT project case study, in which alternative funding scenarios of the initial investment are examined and two specifi c funding scenarios are distinguished, which include all the possible funding ratio values by the public and the private parts. The process that is presented here can be a useful tool to decision makers, because it helps them to evaluate different funding scenarios of the initial investment and to select the most suitable in each case option, that will be profi
INTRODUCTIONNowadays, there is a growing trend for governments in the construction industry to place major projects into the private sector through the Public Private Partnerships (PPPs) [1,2]. In the literature, there is no common defi nition of PPPs [3] and the defi nitions given by many scholars present some differences [4][5][6][7][8]. However, a common point among different approaches is that PPP contracts are long-term agreements for cooperation between public and private sector to provide high quality infrastructure, products or services, delivered via a process of applied risk-sharing, resources and profi ts. Generally, it is mentioned that the operational phase of a PPP project is 10-30 years [9][10][11], while these contract types have many advantages as well as some limitations [12]. For the period 1990-2007, the World Bank Group's [13] database that includes data from 134 countries and 4,300 infrastructure projects with private participation, show that the peak of investment projects in the water and sewerage sector was in the year 1997. In 2007, the investments in the specifi c sector amounted to US$3 billion, within the US$2-3 billion range of the three previous years. However, a remarkable issue is the period 1985-2004 in the USA [14]. Particularly, even though the wastewater projects were 41% and the road projects 20% of the total PPP projects, the investments in the wastewater sector cost much lower, that is US$82 billion against US$577 billion for the relative investments in the road sect...