Near- and far-field model coupling methodology for wastewater discharges

The prediction of pollutant concentrations in the coastal waters is essential for water quality control. The description of physical processes and their implementation in computer models shows that there is neither a “complete model” including all important spatial and temporal scales of the dominant processes nor a standard procedure for the coupling of models. This is explained by deficiencies in either implementing dominant physical near-field processes into a far-field model and/or coupling the models to each other. Capabilities and limitations of modeling techniques applied to waste plume mixing and dispersion from submerged multiport discharges are discussed for environmental impact analysis. The recommended procedure combines the relative strengths of the near-field mixing zone model CORMIX and the Eulerian farfield flow and water quality models within Delft3D.