Graphical abstract Situation 1 An engineer has an incomplete dataset about the quantity and quality of the influent wastewater . She has some ideas about how the influent of the plant should be . She might also have some data about the catchment area . Situation 2 An engineer has information enough about the quantity and quality of the influent wastewater . She would like to translate that into some ASM family model state variables . This is the so called characterisation problem . Situation 3 The engineer has information enough about the quantity and quality of the influent wastewater . However that is only a single realisation of the problem . She would like to feature the uncertainty around these data and to generate other similar influent profiles . a Is there any method to interpolate values so as to increase the frequency of some given WWTP influent data profiles Yes the method of Devisscher et al . based on the use of databases or the ones of Langergraber et al . or Manina et al . based on the use of harmonic functions can help to complete some scarce datasets . Also the phenomenological model of Gernaey et al . has been used with this propose . b Is there any tool to derive influent WWTP data given some properties about the catchment area or the distribution of emission sources Yes the generator of Gernaey er al . provides influent data for urban WWTPs given the population and catchment area characteristics . The generator of De Keyser et al . provides emission profiles expected from a given urban population . The former describes the effect of soil first flush sewer system etc . while the later is only concerned about the very source emission patterns providing profiles that can be used as inputs for sewer WWTP or surface water models . c Are there some benchmark influent data profiles or simple models to generate influent data for urban WWTPs Influent profiles for a WWTP of 100 000 PE are available at http www.benchmarkwwtp.org including dry rain and storm weather conditions . The models of Langergraber et al . or Mannina et al . provide influent profiles for dry weather conditions . The former is accompanied by a set of parameters among which the modeller can select those corresponding to the desired size of tin WWTP under study . d Which would be the main references or tools to improve the understanding of the generating mechanisms in a given catchment area and their relationship with the WWTP influent data Interesting results can be found in the research work conducted by Butler et al . Friedler et al . or Almeida et al . about domestic wastewater generation . This research has been followed by the EU project ScorePP and the work of Ort et al . analysing the most general patterns of daily weekly and yearly emissions . Another good manner of proceed is to use the phenomenological model of. 


Summary: The literature provides a wide range of solutions for WWTP influent data generation. The challenge consists of selecting the most suitable solution for each situation. QRAs requires of generating influent data under hypothetical uncertain conditions. The phenomenological modelling integrates knowledge about the generating mechanisms. More detailed descriptions of the components in the catchment area are required.