What is the average daily flow from a storage tank in mgd?

• A. 5.9 mgd
• B. 6.8 mgd
• C. 9.1 mgd
• D. 7.3 mgd

Answer: (D)

The main idea is that the average daily flow from a storage tank equals the amount of water withdrawn from the tank over a 24-hour period to meet customer demand. The tank serves as a buffer, so the daily outflow should reflect the system’s typical daily consumption, not the tank’s total capacity or a momentary peak. When you’re given data on daily usage or turnover, you use that to determine the average daily withdrawal, which is the flow rate in mgd you’re looking for. The numbers that imply higher peak draws or simply the tank’s size don’t represent the steady, daily balance the tank maintains. So the correct choice is the one that matches the system’s usual daily demand, i.e., the value that corresponds to the average daily withdrawal from storage.