Water treatment emergency: Cost evaluation tools

The European Union is committed to enforce limitations to water pollution through specific directives (UWWTD 91/271/EEC). The delay of some EU member states in transposing these directives has had an impact on the quality of the wastewater treatment system. Therefore, it is necessary to intervene with adjustment procedures and construction of new plants. The aim of the study is to carry out an economic feasibility assessment for the construction costs of an urban wastewater treatment plant of medium-low capacity (< 50,000 Population Equivalent or pe) according to a simplified process diagram, and help in the planning of new investments. We propose a methodology based on cost functions according to two different procedures: synthetic estimate of the costs for civil works and a multiple linear regression for the cost of the electromechanical equipment. These functions show a correlation between the construction costs and the population equivalent and enable us to understand it. The results show greater economic benefit in increasing wastewater treatment plants sizes serving a population equivalent of 5000 pe to 10,000 pe, while further increases are less beneficial.