Calculate the daily BOD load and the approximate population equivalent.
BOD Loading
Formula
BOD load, lb/d = Q, MGD x BOD, mg/L x 8.34 Percent removal = (In - Out) / In x 100 Population equivalent = lb/d / 0.17
Inputs used
- Influent flow (MGD)
- Influent BOD (mg/L)
- Effluent BOD (optional, for removal) (mg/L)
- Population served (optional) (people)
Worked example (White River WRRF, fictional)
- Load = 8.0 x 220 x 8.34 = 14,678 lb/d
- Removal = (220 - 5) / 220 x 100 = 97.7%
- Per person = 14,678 / 72,000 = 0.204 lb/person/d
Tips
- Population equivalent assumes about 0.17 lb BOD per person per day; local values vary.
Results are estimates for operator use. Check units and inputs, and confirm decisions with plant data and procedures.