Weir Loading Rate Calculator
Calculate clarifier weir loading (weir overflow rate) — flow per foot of weir — for circular or rectangular clarifiers.
Formulas
Weir loading = flow ÷ weir length
Circular clarifier weir length = π × D (single-sided launder) or 2π × D (double-sided)
gpm/ft = flow (gpm) ÷ weir length (ft) · gpd/ft = gpm/ft × 1440
Ten States Standards commonly cite 10,000–20,000 gpd/ft for secondary clarifiers.
Weir loading = flow ÷ weir length
Circular clarifier weir length = π × D (single-sided launder) or 2π × D (double-sided)
gpm/ft = flow (gpm) ÷ weir length (ft) · gpd/ft = gpm/ft × 1440
Ten States Standards commonly cite 10,000–20,000 gpd/ft for secondary clarifiers.
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