Wastewater treatment plants for small communities: a methodology for estimation investment and operating costs

Abstract

Due to recent laws and regulations in France, small communities will have to increase their investment rate in waste water treatment plants in the coming years. However, for an objective analysis and comparison of available solutions, and beyond technical arguments, public contractors generally miss economical evaluations. We propose a method for getting references. As for investment costs, treatment chains are split into functional units, and each of them is estimated from a sample of building contracts. Investment costs are then recomposed for different processes, at different capacities. For estimating the operating costs, standard operating tasks are defined, and their cost reconstructed from energy and personnel elementary costs. This method is applied to eleven treatment processes.