The capacity of a pump is most frequently expressed in which of the following units?

The capacity of a pump is most frequently expressed in gallons per minute (GPM) because this unit provides a clear and immediate understanding of the flow rate, which is essential for effective sewage treatment operations. Since pumps are often used to move liquid waste and maintain flow within treatment processes, measuring their capacity in GPM allows operators to quickly assess whether a pump can meet the demand for moving fluids through the treatment system.

Using gallons per minute also aligns well with the common practices in the water and wastewater industry, where many processes and equipment specifications are based on this measurement. It allows for straightforward calculations in conjunction with other flow measurements and helps in making decisions regarding system capacity and operational efficiency.

Other units like cubic feet per day or cubic feet per minute, while they may be used in specific contexts, are less common for expressing pump capacity. Gallons per day, though relevant for certain calculations, do not provide the immediate insight that a per-minute measurement does, especially when dealing with scenarios that require quick adjustments or instantaneous flow assessments.