In Sewer Sediment and Pollutant Transport Models

Several commercial software providers offer in addition to their hydrodynamic urban drainage modeling software a tool for water quality modeling. Yet these quality modeling tools are not common practice in urban drainage design. Prior to start using these quality modules it is of paramount importance to have an insight into these models in order to know what these models (can) do (and cannot do) and how they could be applied. The paper shows the results of a thorough analysis of the quality components of two widely spread hydrodynamic models, namely Mouse (DHI Software, Denmark) and HydroWorks / InfoWorks CS (Wallingford Software, United Kingdom). The focus will be on how both models deal in a different way with the same problem, namely in sewer transport of sediments. The analysis reveals that the adequacy of the quality modules is not as high as compared with the hydraulic model. Care should be taken when using these models. Especially in the case of insufficient field data, the generated results must be analyzed with care and attention. A case study illustrates how the InfoWorks CS software can be used to model the transport of ammonia nitrogen.