Cost-benefit analysis of wastewater reuse in Puglia, Southern Italy

A comprehensive economic analysis of the associated costs and benefits derived from wastewater treatment is a prerequisite for ensuring long-term economic, environmental, and social sustainability. This study aims to improve the economic evaluation of wastewater reuse. A methodological framework is presented for the application of cost-benefit analysis to wastewater project plants. The method considers two alternative scenarios for the irrigation use of treated water: (i) for newly irrigated land; and (ii) as an alternative to current groundwater sources. A case study is carried out in Puglia, Southern Italy, where two thirds of irrigation water comes from groundwater. The results show that improved urban wastewater treatment would increase the regional availability of irrigation water by 60 million m3 per year, about 10% of the overall irrigation water demand. While treatment costs are highly dependent on the incoming effluent quality and plant size, the benefits are quite stable. These results point to a case-specific analysis, whereby the economic convenience of wastewater reuse could be assessed against the local context.