Modelling operational costs of a large water resource recovery facility receiving stormwater contributions

The main objective of this paper is to develop a methodology for modelling dry and wet weather operational costs applied to the Alcântara Water Resource Recovery Facility (WRRF), which is the largest Portuguese WRRF. Following data collection and intensive data treatment and validation, dry weather patterns of WRRF performance were combined with specific operational costs and described by a conceptual model. The impact of infiltration flows on operational costs was identified. The model simulations show a significant variation of distribution costs during wet weather periods compared with dry weather periods. The methodology can be used for predicting dry and wet weather operational costs and for defining dry weather tariffs and wet weather tariffs. Moreover, the analysis of the dry and wet weather period can also be used for infiltration quantification.