Estimate equalization or emergency storage for a wastewater treatment flow interruption. Combine average inflow, peak conditions, outage duration, existing liquid volume, and a freeboard allowance to find the total tank size required. The result also shows net new storage and compares the requirement with available capacity.
Required total tank size includes the entered freeboard fraction. Net new storage is the additional liquid volume arriving during the outage, while capacity margin compares total geometric capacities.
Actual design may need rainfall, return flows, sludge displacement, mixing volume, minimum operating level, redundancy, and regulatory storage requirements.
At 120,000 gal/day, a 1.5 peak factor, and an 8-hour outage, incoming storage is 60,000 gallons. Adding 20,000 gallons already present gives 80,000 gallons of liquid. With 15% freeboard, required total tank size is about 94,118 gallons; a 100,000-gallon tank has about 5,882 gallons of total-capacity margin.
The maximum liquid volume is divided by one minus the freeboard fraction, increasing total geometric capacity.
Yes. Enter the volume expected to be in the tank when the outage or diversion begins.
Average inflow is entered in gallons per day, so hours are converted to a fraction of a day.
Only if it is reflected in the entered average flow and peak factor; otherwise add it to the design basis separately.
It is the peak wastewater volume arriving during the selected outage period, before adding existing liquid.
| Design quantity | Basis | Unit |
|---|---|---|
| Average inflow | Measured daily flow | gal/day |
| Peak inflow | Average × peak factor | gal/day |
| Outage volume | Peak × hours/24 | gallons |
| Total tank | Liquid volume ÷ usable fraction | gallons |