Subject: Water Quality Treatment Removal Variables in SWMM5
The treatment variables for Water Quality in a SWMM 5 storage unit (Figure 1) can be either:
1. A Process Variable
a. HRT or Hydraulic Residence Time
b. DT or Time Step
c. FLOW or The Current Inflow
d. DEPTH or the Mean Flow over the Time Step
e. AREA or the Mean Area over the Time Step
2. Pollutant Concentration
3. Pollutant Removal based on the Removal of Other Pollutants
With a Wide Range of Treatment Functions (Figure 2).
Figure 1. SWMM 5 Treatment Variable Names in the Treatment Equation
Figure 2. Treatment Functions in SWMM 5
