Ejector or educator dewatering systems is a specialist technique used to control pore water pressures and to lower groundwater levels in low permeability ground conditions. Ejector systems are able to extract groundwater and generate a high vacuum at the base of wells up to 50m deep and as little as 50mm in diameter.
Why Use Ejector Systems?
WJ Groundwater has successfully used ejectors to dramatically improve the stability of silty fine sands and laminated silts and clays by controlling excess pore pressures.
Although flows of water into a tunnel, shaft or excavation may be very low, say less than 10l/s, the excavation can remain unstable until an ejector dewatering system is installed and operated.
Ejector supply pumps located at ground level feed high pressure water to the ejector nozzle and venturi located at the base of the wells. The flow of water through the nozzle generates a vacuum in the well and draws in groundwater. This in turn lowers the groundwater level and control pore pressures allowing work to continue safely.
WJ Groundwater is a leading expert in the design, installation and maintenance of the ejector dewatering systems. Please contact us for further information.