Basic Wastewater Operator Practice Exam

What is a common cause of reduced pump discharge rate?

1. Blockage in discharge line

2. Blockage in intake

3. Low power supply

4. Low flow into station

The correct answer is: Blockage in discharge line

A blockage in the discharge line is a common cause of reduced pump discharge rate because it directly restricts the flow of water leaving the pump. When there is an obstruction, whether from debris, sediment, or damage to the line, the pump has to work harder to push the water through, which can lead to decreased efficiency and reduced flow rates. This can result in increased pressure on the pump and potential damage over time if not addressed. While blockages in the intake and low power supply can impact pump performance, they typically do not directly lead to a lower discharge rate in the same manner as a blockage in the discharge line. Blockages in the intake can restrict the amount of water entering the pump, reducing overall input rates but typically not the discharge flow by itself. Low power supply could lead to pump underperformance, but this is more related to operational inefficiencies rather than a direct blockage. Low flow into the station may affect the overall system flow but does not specifically cause a reduction in the discharge rate of a pump that is operating, provided it is functioning correctly at intake.