Unit Filter Run Volume (UFRV) Calculator

How much water did each square foot of media actually produce this run? Enter the filter’s flow, area, and run length to get UFRV — the trend that warns you before breakthrough does.

Flow through this filterUse the single filter being evaluated, not plant total.

Flow unit

Filter area (ft²)

Filter run length (hours)Time between backwashes.

Unit Filter Run Volume

Item	Value

How the calculation works

Formulas
UFRV (gal/ft²) = volume filtered in one run (gal) ÷ filter area (ft²)
Volume (gal) = flow (gpm) × 60 × run length (hr)
1 MGD = 694.44 gpm

Notes & limitations

UFRV is a standard filter performance indicator used in state and EPA filter surveillance guidance (e.g., composite correction program reviews). It normalizes production so runs and filters can be compared directly.

The ~5,000 gal/ft² review benchmark is a commonly cited plant-level flag, not a regulation — your state’s filter performance criteria govern. Track UFRV as a trend, not a single number.
UFRV assumes roughly constant flow during the run. Declining-rate filters and flow swings distort it — use average flow for the run.
A rising UFRV trend with stable raw water can mean coagulation or backwash is slipping. Pair UFRV with effluent turbidity and head-loss trends.

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