Which of the following is the correct unit for measuring flow rate in gallons per minute?

The correct unit for measuring flow rate in gallons per minute is expressed as GPM, which stands for "gallons per minute." This unit specifically indicates the volume of liquid flowing per minute and is commonly used in various applications, including wastewater management, to monitor flow rates in treatment plants and collection systems.

GPD, or gallons per day, measures the volume over a 24-hour period, which is useful for different contexts but not suitable for indicating flow rates at a moment in time. MGD stands for millions of gallons per day and is predominantly used for larger systems, such as municipal water treatment facilities, to express flow rates in much larger volumes. CPM, or cycles per minute, is a unit that relates to frequency rather than flow rate, making it irrelevant in this context.

Understanding these distinctions helps in selecting the proper unit for the measurement needed in wastewater operations and assessments.