Following is the appearance of the Septic Systems tab of the Catchment Coefficients dialog:
Following is a description of the parameters associated with Septic Systems. Refer to the main Catchment Coefficients page for information on other categories of coefficients. To save the changes made when closing this dialog, click OK. To ignore changes, click Cancel.
Discharge Layer is the soil layer into which septic tank effluent is discharged (usually 1)
Population Served by Septics is the population within the selected catchment using septic tanks for wastewater disposal (>=0)
Distribution of Septic Systems is the percent of septics within the selected catchment that use each type of septic system. The water quality effluent of each system type is defined in the System Septic System Coefficients
Initial Biomass is the initial condition for a biomass density in the biozone. (>=0 g/cm2)
Biozone Thickness is the thickness of the biozone in this catchment (usually 2 cm)
Biozone Area is the average biozone area (soil adsorption area) for each septic system (usually ~80 m2)
Biomass Respiration is the respiration rate of the biomassl (usually ~0.18 / day)
Biomass Mortality is the mortality rate of the biomass (usually ~0.29 / day)
When the Apply Changes To Selected Catchments button is checked, changes made to the coefficients of the catchment being edited will be made to all selected catchments. When the Apply Changes To All Catchments button is checked, changes made to the coefficients of the catchment being edited will be made to all catchments.