Computer-aided design of effluent irrigation

Effluent irrigation systems are engineering systems that have been identified as an attractive option for effluent disposal in Australia for environmental pollution control and resource reuse. As engineering systems, they should be designed based on established engineering procedures. At the moment, the systems are designed mainly on the guidelines issued by individual states in Australia, which are general engineering practices. However, the guidelines are quite different in different states. There are no generalised and commonly acceptable design procedures available for reference. This paper reports a generic calculation model for effluent irrigation design, and a decision support system called Computer-Aided Design of Effluent (CAD-Effluent) that was developed based on the model. The model can accommodate different methods of estimating sustainable effluent loading rates such as the methods specified in guidelines, simulation models that describe the pollutant transformation processes in soils, or other empirical methods. The application of CAD-Effluent is demonstrated using Queensland guidelines and climate data from thirty-one locations.