ECONOMIC EVALUATION OF WATER TREATMENT USING CONSTRUCTED WETLAND "CASE STUDY: Lake Manzala Project" التقييم الاقتصادي لمعالجة المياه باستخدام الأراضي الرطبة المشيدة دراسة تطبيقية: علي مشروع بحيرة المنزلة

                ,Egypt confronts a number of water-related challenges, which obstruct its ambitious development plans. These challenges led to the use of wastewater after applying adequate treatment as an economic alternative with a definite environmental and social dimension .

While the government has made remarkable efforts towards improving the quality of water during the last decades implementing a number of plans to increase water use efficiency, reduce wastewater production and abate source point pollution. Yet water quality of large waterways is still questionable and do not comply with the international nor the national water quality standards (El-Saharty S. et al., 2005).

The increasing gap between wastewater-generated quantities and the capacity of existing treatment facilities, on one hand, and the unaffordable budgets required for the full coverage with treatment services applying conventional treatment methods, on the other hand, led to exploring the applicability of the constructed wetland treatment method as unconventional solution.

Nevertheless, the question that remains to be answered: Does the constructed wetland present a comparative wastewater treatment system for water with low quality, within the Egyptian conditions, providing water of adequate quality that can be reused safely in agriculture in a technically feasible, environmentally sound while economically viable way?

The importance of the economic evaluation study has emerged out of the high costs of construction, maintenance and operation of most of the conventional treatment processes (Tsagarakis et al., 2003). Owing to the innovation of applying the constructed wetland treatment method in Egypt, its economics did not receive adequate attention in the literature. Therefore, and while attempting to decide on the most applicable economic evaluation method to appraise the use of constructed wetland method in wastewater treatment taking into account the Egyptian economic and social circumstances.

The research concluded the importance of enforcing the economic evaluation study in the appraisal process of all development projects in general and the wastewater treatment projects in particular to guarantee the selection of the optimal alternative from the societal point of view. As the interaction between the economic activities and the environment is well known and should be deliberated when evaluating the feasibility of any developmental project to guarantee the allocation of the society’s finite resources in projects that would not negatively influence its potentiality, taking into consideration the transferred cost; externalities; either to other sectors or to the general public.

The economic viability of the constructed treatment wetland has been evaluated by applying a comparative study of the economics of the constructed wetland versus other treatment methods when applicable, where the economics of the Egyptian experience is compared with the experiences of a number of countries within the available data. It is worth mentioning that the main constraint faced the study was the insufficiency of economic and financial data. Nevertheless, the available data gave comparative signification on the viability of this treatment method.

The study concludes that the constructed wetland treatment method is viable from the economic viewpoint where land is available at affordable price as the application of this method occupies large areas of land, which would be feasible in remote and impoverished areas. The study emphasizes that constructed wetland treatment method when appropriately managed harmonizes with the surrounding environment gaining public approbation and would represent a focal point sustaining economic development in the surrounding area.