Calculate wastewater treatment water recovery using influent, reclaimed-water production, internal recycle, and qualifying losses. The adjusted recovery rate excludes internal recycle from new recovered output and reports net reclaimed water, unrecovered flow, and the gap to a user-defined target. Use it for consistent operating-period comparisons.
The adjusted rate compares new reclaimed-water production with the eligible influent volume. Removing internal recycle avoids counting the same water as fresh recovery more than once.
Only exclude losses when the reporting protocol permits it and measurements share the same time basis. Mass balance may also require sludge moisture, evaporation, and inventory changes.
With 1,000,000 gal/day influent, 760,000 gal/day measured output, 40,000 gal/day internal recycle, and a 20,000 gal/day qualifying loss, net reclaimed output is 720,000 gal/day. Dividing by 980,000 gal/day adjusted influent gives a 73.5% recovery rate, 6.5 percentage points below an 80% target.
Internal recycle is water already within the process and should not be counted again as newly recovered product.
Only when the applicable operating or reporting protocol defines it as a qualifying exclusion and it is measured consistently.
The inputs are inconsistent for this calculation; the calculator asks you to correct them.
It is the calculated recovery rate minus the entered target, expressed in percentage points.
A value above 100% usually indicates mismatched periods, recycle double counting, inventory change, or meter error.
| Balance item | Adjustment | Reason |
|---|---|---|
| Measured product | Starting output | Meter reading |
| Internal recycle | Subtract | Avoid double count |
| Influent | Starting denominator | New wastewater |
| Qualifying loss | Subtract if allowed | Reporting basis |