The area required to settle the 1 mm particles is calculated as:
The area required to settle the 1 mm particles is calculated as:
:<math>A_{f}=120\times 0.1 = 12\ m^{2}</math>
:<math>A_{f}=120\times 0.1 = 12\ m^{2}</math>
So to meet the target particle removal, the forebay will be 12 m² in area. This gives the storage volume of 1.2 m³, which can be returned to the initial equation to determine the cleaning frequency as:
So to meet the target particle removal, the forebay will be 12 m² in area. This gives the storage volume of 1.8 m³, which can be returned to the initial equation to determine the cleaning frequency as: