Cost analysis of the facilities deterioration in wastewater treatment plants: A dynamic approach

The implementation of the Directive 91/271 / CEE resulted in the proliferation of new Wastewater Treatment Plants (WWTPs) all around Europe. These facilities, which are compound by a wide range of assets (civil works, electromechanical equipment, pipelines, etc.), are ageing and deteriorating having an impact on the efficiency of the process. It is founded that repairs and corrective maintenance costs have increased in the last years, due to the deterioration process. Therefore, the aim of the present study is to focus on the cost effects of the deterioration process of the facilities in different wastewater treatment technologies. The analysis of these impacts will allow the operators to make decisions on the convenience of applying a preventive maintenance program as well as the selection of the best time for the replacement of the equipment. These results will contribute to the technical and economic optimization of the wastewater treatment process, reducing, also its environmental effects. In order to achieve this purpose a model of the repairs and corrective maintenance cost will be developed for a group of WWTPs with extended aeration and activated sludge technologies, offering valuable results for the managers of the WWTPs in the decision making process.