musicincorporates the ability to display the predicted probabilisticwater quality conditions at source nodes (e.g. urban subcatchment),treatment nodes (e.g. wetland) or receiving nodes, against local orregional water quality concentration standards. Exampleconcentration standards for TSS, TP and TN are provided, howeverthese should only be taken as a guide and do not constitute adoptedstandards for any particular location. You can add any relevantvalues that they wish and these are then reflected in the chartswhen the model is run and the charts are displayed.
The mostappropriate water quality concentration standards for the catchmentyou are investigating are likely to be those that have been derivedfor that specific catchment, or at least the local region. Use ofthe example concentration standards is only to demonstrate how thestandards may be displayed in the graphs and do not represent anyparticular locality.
Selected water quality standards can be displayed on either theTime Series Graph or Cumulative Frequency Graphs (more detail onthese is provided in Chapter 4).
Water quality concentration standards are usually specified inthe form of a threshold water quality concentration value, and arequired compliance frequency for that value. The use of thecumulative frequency curves is the best means of assessing theperformance of a stormwater quality treatment strategy against thewater quality standards. For example, the TSS standard for Brisbanespecifies a median daily value of 15mg/L. This means that TSSconcentration in Brisbane should not exceed 15mg/L more than 50% ofthe time.
Irrespective of the time-step used in model simulation, themodel compiles predicted water quality concentrations forcumulative probability analysis in several forms:
You can choose the time-step of analysis for the production ofstatistics. For example, even if the model is run at a 6 minutetime-step, statistics can be produced at an hourly or dailytime-step, if required.