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Dewatering and groundwater control | Stuart Well Services Ltd

Wellpointing

Air Sparging

For most shallow excavations and pipelines vacuum wellpoints offer an economical and effective method of groundwater control.

Wellpointing

Wellpoint dewatering systems typically consist of a series of small diameter uPVC or steel riser pipes, that has a filter intake element at the base, that are installed at close centres (typically 1.0m to 2.0m centres) around an excavation or alongside a pipeline trench.

In turn individual wellpoints are connected via flexible control swings at the surface to a collection pipe or header main (galvanised steel or HDPE). This is connected to a vacuum pump (centrifugal or piston type) that abstracts groundwater to a discharge point. Typically, a single pump will operate ~100 lin.m of header main.

Well Pointing

Although ground conditions will dictate the dewatering design wellpoints are effective for most excavations up to 5m-6m deep. In fine soil conditions or deeper excavations, the wellpoint system is installed from, and pump positioned at a reduced ground level. For greater depths, if space permits, multi-stage systems can be installed.

Wellpoints are predominantly used for temporary construction dewatering. However, they can be used for permanent dewatering schemes and as a means of abstraction for irrigation or private water supply systems.

Wellpoints are installed using a variety of methods. For most projects’ wellpoints are installed using conventional jetting method. This involves pumping water at high pressure (supplied by a jetting pump and/or compressed air) through a steel placing tube suspended by a 360° excavator. If an upper Clay is present, then wellpoints maybe pre-augured using a hydraulic auger connected to a 360° excavator.

Well Pointing

In restricted conditions wellpoints can be installed manually using self-jetting wellpoints (steel or uPVC). In other cases where rock or cobbles are present, wellpoints will be drilled in using a small rotary drilling rig.

For more information on well pointing, please contact Stuart Wells Limited.

Accreditations

FORS - Fleet Operator Recognition Scheme
ISO-9001 ISO-14001
ISO-22301 ISO-45001
ISO-45001
ISO-45001
ISO-45001