What is the purpose of the timer on the pump in a pressurized system?

• A. To switch the pump on and off at specified times so that the effluent discharged to the trench will not saturate the receiving soil.
• B. To regulate the flow rate of the pump to a fixed speed.
• C. To monitor the moisture content of the soil.
• D. To prevent freezing of the pump.

Answer: (A)

The timer is used to dose the effluent in controlled pulses rather than in a continuous flow. In a pressurized system, turning the pump on and off at set intervals releases small amounts of wastewater to the trench, giving the soil time to absorb each pulse. This prevents the receiving soil from becoming saturated, avoids ponding at the surface, and keeps the leaching field operating within its absorption capacity.

Flow rate regulation is not the timer’s job—the pump speed or a flow-control device determines how fast the liquid is pumped. Monitoring soil moisture is done with sensors, not a timer. Preventing freezing relies on other measures like insulation or heat tracing, not the timer function.