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Latest News and Updates from WJ Groundwater and across the Industry.

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Sump Pumping

Sump Pumping

Sump pumping is the simplest form of dewatering and can be very reliable. Groundwater is allowed to flow into the excavation and is collected in sumps where it is then pumped away. In certain conditions, sump pumping can be very efficient and is highly cost effective, however uncontrolled seepage into the excavation can cause instability and other construction problems. Additionally, the disposal of the water needs to be handled carefully, to ensure that the quality of the water is suitable for discharge.

 

Why Use Sump Pumping?

Sump pumping is particularly suited to shallow excavations in permeable soils, and for deeper excavations in rock or cemented soils where there is no concern over ground stability and seepage flow conditions.

WJ Groundwater has a wealth of experience in using sump pumping as a method of dewatering. Rest assured that our expert team and innovative technology means we are fully equipped to install the sum pump safely, oversee the operation and ensure that the water is disposed of safely and ethically.

 

Featured Sump Pumping Projects

DLR Extension, Greenwich

DLR Extension, Greenwich

  • Deepwell Dewatering
  • -Read More-
  • Crossrail Cross Passages

    Crossrail Cross Passages

  • Well Drilling
  • Probe Drilling
  • -Read More-
  • Nottingham One, Canal Street

    Nottingham One, Canal Street

  • Sump Pumping System
  • -Read More-
  • Sump Pit Completion at Caledonia Station

    Sump Pit Completion at Caledonia Station

    In the world of dewatering, clay is clay. No matter how thin, a continuous layer can quickly change dewatering requirements.

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    WJ Group AdminSump Pumping
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    Syphon Draining

    Syphon Draining

    Siphon drain system used for slope stability

    Siphon drain system used for slope stability

    The syphon drain process is an innovative and proven solution developed by TP Geo in France to work with unstable slopes.

    Syphon draining works by pumping water by gravity along primed siphon pipes. Wells are installed in or above the unstable zone of a slope and are pumped using siphons which exploit the natural sloping terrain. The wells reduce the pore pressure increasing the effective stress and stabilising the slope.

    Priming of the syphon is controlled by an automatic flushing system located at the downstream outlet of each siphon pipe. This enables the siphon to operate intermittently at low flows, maintaining the prime by preventing the build-up of air in the syphon.

     

    Why Use Syphon Draining?

    This dewatering method is used for long term low flow rate pumping where a naturally sloping terrain can allow the system to operate.

    WJ Groundwater has worked with TP Geo for the past 10 years and has partnership agreement for projects in the UK and Ireland.

    Our highly trained team at WJ Groundwater have vast experience in dealing with syphon draining techniques. We can offer a complete solution from designing the system for your project, through to drilling and installation. Our professional management and on-site teams can deal with all operation and maintenance activities including pump testing and monitoring to ensure that the project is completed safely, efficiently and cost effectively.

    Featured Syphon Draining Projects

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    WJ Group AdminSyphon Draining
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    Wellpoint Systems

    Wellpoint Dewatering

    Wellpoint dewatering system

    Wellpoint dewatering system

    Wellpoint systems are used to lower groundwater levels to provide stable working conditions. They consist of a series of small diameter wells that are connected by a header pipe to a wellpoint pump. The pump creates a vacuum in the header pipe drawing water up from the ground.

    Welpoints are typically installed along or around an excavation. The height to which water can be drawn by vacuum in this way is approximately 6 metres. To function at greater depths, well points can be installed in stages as the excavation proceeds.

     

    Why Use Wellpoint Systems?

    Wellpoint systems are particularly suited to dewatering for shallow foundations and excavations, so they are often used for pipeline trench work. A wellpoint system can be installed quickly in most ground conditions and they are easy to maintain.

    With perhaps one of the most extensive and modern fleet of wellpoint installation equipment around, WJ have installed wellpoint dewatering systems all over the world for a wide range of projects from major infrastructure projects such as Crossrail in the UK, Eglinton LRT in Toronto and Dubai’s International Airport, to small city centre basement extensions, and everything in between!


    Range of application for wellpoint dewatering systems on construction projects (based on CIRIA 515, London 2000)

    Range of application for wellpoint dewatering systems on construction projects (based on CIRIA 515, London 2000)

    Featured Wellpoint Projects

    Dorset Fire & Police Headquarters

    Dorset Fire & Police Headquarters

  • Deepwell Dewatering
  • Wellpoint Dewatering
  • -Read More-
  • Crossrail Underground Station at Farringdon

    Crossrail Underground Station at Farringdon

  • Well Drilling
  • Probe Drilling
  • -Read More-
  • Scottish Power HQ

    Scottish Power HQ

  • Wellpoint Dewatering
  • -Read More-
  • Crossrail Cross Passages

    Crossrail Cross Passages

  • Well Drilling
  • Probe Drilling
  • -Read More-
  • read more
    WJ Group AdminWellpoint Systems
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    Ejector Systems

    Ejector Systems

    Ejector dewatering system

    Ejector dewatering system

    Like the deepwell systems, the ejector or eductor system is based on wells that are drilled to lower the groundwater level to provide stable working conditions. Ejectors use air within the wells to produce a vacuum to draw water out of the soil.

    The system works by circulating high pressure water which is fed from a tank and supply pumps at ground level down the well into the ejector nozzle and venturi located at the foot of the well. The flow of water through the nozzle generates a vacuum in the well and draws in the groundwater. It is then piped back to ground level and back to the supply pump for recirculation.

     

    Why Use Ejector Systems?

    Ejector dewatering systems work to control pore water pressure in low permeability soils so this method of dewatering is best suited for sites with soils such as silts and fine sands.

    WJ have a wealth of expertise and a high reputation for installing and operating ejector systems for notoriously difficult projects, including Crossrail and Conway Crossing in the UK and Eglinton LRT in Canada.

     

    Range of application for ejector dewatering systems on construction projects (based on CIRIA 515, London 2000)

    Range of application for ejector dewatering systems on construction projects (based on CIRIA 515, London 2000)


    Featured Ejector Dewatering Projects

    HS1 Ashford Tunnels

    HS1 Ashford Tunnels

  • Ejector Dewatering
  • -Read More-
  • Crossrail Stepney Green Shaft & Junction

    Crossrail Stepney Green Shaft & Junction

  • Ejector Dewatering
  • Well Drilling
  • Probe Drilling
  • -Read More-
  • Provost Driver Court, Renfrew

    Provost Driver Court, Renfrew

  • Provost Driver Court
  • Ejector Dewatering System
  • -Read More-
  • Cross Cut Completion at Oakwood Station

    Cross Cut Completion at Oakwood Station

    A challenging commission, which combined difficult dewatering conditions with innovative construction techniques.

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    WJ Group AdminEjector Systems
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    Deepwell Systems

    Deepwell Systems

    Deepwell dewatering system

    Deepwell dewatering system

    A deep well system consists of an array of bored wells, each fitted with a multi-stage electric submersible borehole pump. As water is pumped from each well, the groundwater is lowered creating a cone of depression or drawdown around itself.

     

    Why Use Deep Well Systems?

    Deepwell dewatering is suited to deep excavations and where soil permeability is moderate to high. Deepwell systems also work well where artesian groundwater pressures threaten base stability. Capable of pumping tens of thousands of gallons of water per minute, deepwell systems are effective when there are large volumes of groundwater. The flexibility on the well depth and the well spacing means access restrictions are kept to a minimum.

    WJ have decades of experience in providing deepwell dewatering solutions all over the globe from the UK (Crossrail in the UK), to mainland Europe (Lodz Highspeed Rail Interchange in Poland), the Middle East (Dubai International Airport) and Canada (Eglinton LRT in Toronto). Our highly skilled team are fully equipped to deal with all aspects involved, ranging from designing the dewatering system, to drilling and installation, pump testing, monitoring and on-site maintenance. No matter what the size of your project, we can offer a full tailored solution to suit your requirements.

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    Range of application for deepwell dewatering systems on construction projects (based on CIRIA 515, London 2000)


    Featured Deepwell Projects

    Dorset Fire & Police Headquarters

    Dorset Fire & Police Headquarters

  • Deepwell Dewatering
  • Wellpoint Dewatering
  • -Read More-
  • Riverside South Development, Canary Wharf

    Riverside South Development, Canary Wharf

  • Deepwell Dewatering
  • -Read More-
  • Crossrail Station, Canary Wharf

    Crossrail Station, Canary Wharf

  • Deepwell Dewatering
  • -Read More-
  • Fairlight Cove Coastal Protection

    Fairlight Cove Coastal Protection

  • Siphon System
  • -Read More-
  • read more
    Neil.CoulterDeepwell Systems