Eductor systems are most advantageous when dewatering deep excavations where the volume of water to be pumped is relatively small because of the low permeability of the aquifer. Like vacuum wellpoints, eductor wells are spaced 2 to 10 feet on center; however, unlike vacuum wellpoints, eductor wells do not have drawdown limitations. Installation of eductor wells is similar to vacuum wellpoints but eductor wells can lift water deeper than 25 feet.

In operation, water under pressure from the eductor pump enters the eductor through the pressure nozzle and venturi, causing a difference in pressure, which creates a vacuum that draws the groundwater through the well screen and flows up into the body of the eductor where it is entrained by the pressure water. Both liquids are mixed in the body of the eductor and are discharged against back pressure up to the ground surface.

For more information, contact Matt Kennedy – mkennedy@malcolmdrilling.com