Multiple pump requirement occurs at what flow?

• A. 5,000 gpd
• B. Greater than 15,000 gallons per day
• C. 20,000 gpd
• D. 1,000 gpd

Answer: (B)

When you design a pumping system, you add multiple pumps to ensure enough capacity and to provide backup in case one pump fails. The standard boundary for needing more than one pump is a daily flow that is greater than 15,000 gallons per day. If the system’s flow exceeds 15,000 gpd, two pumps (or more) are typically required to meet demand and maintain service during maintenance or a pump outage. So the threshold itself is the key idea: greater than 15,000 gpd triggers the need for multiple pumps. (A value like 20,000 gpd is also above the threshold and would require multiple pumps, but the important point is the 15,000 gpd boundary.)