Pump tanks are concrete, fiberglass or polyethylene containers that collect wastewater to be pressure-dosed to the next component. Pump tanks are a component of several types of onsite wastewater treatment technologies, including low-pressure dosing, subsurface drip distribution, media filters, and spray systems.
These systems can be dosed with timer controls, that dose a set amount of effluent at specific time intervals, or they can be demand dosed, which dose the effluent when a certain volume is collected in the tank.
The pump tank collects wastewater until it is dosed into the next component in the onsite wastewater treatment system. The tank must be watertight to prevent wastewater from seeping out and groundwater from entering. It must be big enough to hold the amount of wastewater distributed during dosing. It also must be able to store a minimum amount of wastewater for the pump to operate properly, and to store a certain amount of wastewater after a high-water alarm is triggered.
Most residential pump tanks have a 500 gallon capacity. However, larger tanks (such as a 1,000-gallon tank) can be used to provide about 2 days of flow storage after a high-water alarm is triggered.