What is the reported flow per person per day?

• A. 100 gallons per day
• B. 50 gallons per day
• C. 200 gallons per day
• D. 25 gallons per day

Answer: (A)

Flow per person per day is a planning figure used to estimate how much wastewater each resident contributes daily. The commonly reported value is 100 gallons per person per day. This baseline reflects typical indoor water use from flushing, showers, sinks, and laundry, plus a margin for infiltration. It provides a convenient way to size treatment plants and estimate total daily flow by multiplying this figure by the population served. In reality, per-person wastewater generation can vary with water-use habits and climate, but 100 gpd remains the standard reporting figure because it offers a reliable, conservative estimate for planning.