Water Consumption / Discharge Calculator

Calculates combined water supply and sewerage/discharge cost using the standard return-to-sewer billing method.

Water Consumption (m³/month)

Water Supply Rate ($/m³)

Return-to-Sewer Percentage (%) Portion of supplied water assumed to be discharged as wastewater (commonly 80-95% for typical facilities; less for processes with high evaporation/consumption).

Sewerage/Discharge Rate ($/m³)

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Water Supply Cost

0 m³

Discharge Volume

Total Water + Sewerage Cost

Formula Reference — Return-to-Sewer Method

Water Supply Cost = Water Consumption × Water Rate
Discharge Volume = Water Consumption × Return-to-Sewer %
Sewerage Cost = Discharge Volume × Sewerage Rate
Total Cost = Water Supply Cost + Sewerage Cost

This is the standard utility billing methodology used by most municipal/industrial water authorities: since discharge volume is rarely metered directly, it's estimated as a percentage of metered supply (the "return-to-sewer" or "consumptive loss" factor), accounting for water lost to evaporation, product incorporation, irrigation, or other non-discharged uses.

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Water Consumption / Discharge Calculator

Formula Reference — Return-to-Sewer Method

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