How many pounds per day per person of nitrogen are added?

• A. 0.01 lbs
• B. 0.05 lbs
• C. 0.04 lbs
• D. 0.02 lbs

Answer: (D)

Nitrogen loading from people to a wastewater flow is typically estimated around 8–12 grams of nitrogen per person per day. Converting to pounds, that’s about 0.017–0.026 lb/day, so 0.02 lb per person per day is a representative value used in design calculations.

Choosing 0.02 lb/day makes sense because it sits in the common range for daily N excretion; 0.01 lb/day corresponds to only about 4–5 g N/day, which is low for most diets; 0.04 lb/day is about 18 g N/day, and 0.05 lb/day is about 23 g N/day—both higher than typical estimates.