Evaluation of the decision making model for choosing the wastewater treatment system of Pardo Drainage Basin cities

Abstract

According to the State of São Paulo 1989 Constitution, it is forbidden to throw urban effluents without the proper treatment in any watershed. The use of drainage basins as environmental management units expanded the solution of environmental problems to bigger interference areas, improving the waters management. The wastewater treatment system to be chosen and installed in a city can become a difficult decision, once the many variables interfere in its cost and environmental quality. The objective of this research is to test de decision making model of the wastewater treatment system selection developed by Oliveira (2004) in cities pertaining Pardo Drainage Basin, in order to identify which treatment system is more adequate to attend social, environmental and economic need of these cities. The present study will be an applied research, using the mathematical model to evaluate the alternatives of smaller monetary value, to assist choosing the sanitary sewer treatment system. The model elaborates the sizing of the treatment units and, from these inputs, the cost estimate of each system, composed by items of implementation, operation and maintenance, for a determined life span. Interviews will be realized with the decision makers and responsible for the sanitation of these cities, in order to collect the necessary data to apply the model, as well as verify how were chosen the treatment systems already defined in a few cities. It is wanted to do some adequacies in the model with this research, as well as to assist the cities to choose their wastewater treatment system. (AU)