Dilution Capacity Low Flow
Invert ideal complete mixing for an effluent flow capacity when receiving concentration < target < effluent; not a legal discharge allowance, mixing-zone model or ecological guarantee.
Description
Ideal complete mixing blends receiving water and effluent by their flow-weighted concentrations.
Ideal complete mixing blends receiving water and effluent by their flow-weighted concentrations. Inverting the balance estimates the effluent flow corresponding to a chosen mixed concentration.1
The tool returns maximumModelEffluentFlowM3PerSecond, flowMarginM3PerSecond, completeMixConcentrationMgPerLiter. The computation uses supplied observations and parameters rather than acquiring measurements.
When to use Dilution Capacity Low Flow
Use this for the following task: Invert ideal complete mixing for an effluent flow capacity when receiving concentration < target < effluent; not a legal discharge allowance, mixing-zone model or ecological guarantee. Prepare observations and calibration parameters on the same unit and reporting basis.
How to use Dilution Capacity Low Flow and understand its results
- Prepare the measured quantities and supplied model parameters. Match the units and align paired lists before calculating.
- Enter lowReceivingFlowM3PerSecond, receivingConcentrationMgPerLiter, effluentConcentrationMgPerLiter, targetMixedConcentrationMgPerLiter, proposedEffluentFlowM3PerSecond according to the field table, then run the tool.
- Read maximumModelEffluentFlowM3PerSecond, flowMarginM3PerSecond, completeMixConcentrationMgPerLiter. Use the calculation below to interpret the selected mean or the model’s signs, units and comparison flags.
- Review the supplied assumptions and calibration before comparing or reporting the result.
| Input field | Meaning | Value type and bounds | Requirement |
|---|---|---|---|
| lowReceivingFlowM3PerSecond | Low receiving flow m3 per second | number | Required |
| receivingConcentrationMgPerLiter | Receiving concentration mg per liter | number | Required |
| effluentConcentrationMgPerLiter | Effluent concentration mg per liter | number | Required |
| targetMixedConcentrationMgPerLiter | Target mixed concentration mg per liter | number | Required |
| proposedEffluentFlowM3PerSecond | Proposed effluent flow m3 per second | number | Required |
Supply positive receiving flow, nonnegative concentrations and proposed effluent flow, with receiving concentration strictly below target strictly below effluent concentration. Return model capacity, signed margin and proposed-flow mixed concentration.
maximumFlow=receivingFlow×(target−receivingConcentration)/(effluentConcentration−target); mixed=(Qr×Cr+Qe×Ce)/(Qr+Qe) The symbols and boundary conditions refer to the supplied fields and the implementation described above.
| Output field | Meaning | Value type |
|---|---|---|
| maximumModelEffluentFlowM3PerSecond | Maximum model effluent flow m3 per second | number |
| flowMarginM3PerSecond | Flow margin m3 per second | number |
| completeMixConcentrationMgPerLiter | Complete mix concentration mg per liter | number |
{
"input": {
"lowReceivingFlowM3PerSecond": 10,
"receivingConcentrationMgPerLiter": 1,
"effluentConcentrationMgPerLiter": 11,
"targetMixedConcentrationMgPerLiter": 3,
"proposedEffluentFlowM3PerSecond": 2
},
"output": {
"maximumModelEffluentFlowM3PerSecond": 2.5,
"flowMarginM3PerSecond": 0.5,
"completeMixConcentrationMgPerLiter": 2.6666666666666665
}
}Limitations and assumptions
This is an instantaneous complete-mixing model. It does not determine a legal discharge allowance, mixing-zone concentration, chemical reaction or ecological outcome.
Numerical inputs must be finite. Input-shape and calculation checks do not establish measurement quality or the validity of a supplied calibration.
Alternative or Complementary methods
Choose Chloride Conservative Mass Balance Checker when you need its operation: Audit conservative dissolved chloride inventory with trapezoidal sampled mass-flux integration and independent final inventory; this tracer is not chlorine disinfectant, and groundwater/deposition inputs must be included externally. Choose Evaporation Pan To Lake Coefficient for the complementary operation: Infer a pan-to-lake coefficient from a matched fixed-area observed lake water budget; negative inferred evaporation/coefficient exposes condensation or missing fluxes rather than being forced to an empirical default.
Background reference: NPDES Permit Writers’ Manual, Chapter 6: simple mass balance.
References
-
NPDES Permit Writers’ Manual, Chapter 6: simple mass balance — U.S. Environmental Protection Agency
Similar or alternative tools
- Chloride Conservative Mass Balance Checker
Audit conservative dissolved chloride inventory with trapezoidal sampled mass-flux integration and independent final inventory; this tracer is not chlorine disinfectant, and groundwater/deposition inputs must be included externally.
- Evaporation Pan To Lake Coefficient
Infer a pan-to-lake coefficient from a matched fixed-area observed lake water budget; negative inferred evaporation/coefficient exposes condensation or missing fluxes rather than being forced to an empirical default.