Well Point Dewatering System Procedure

Generally well point system is used to lower the ground water table up to 6 m or less.

Well point dewatering system procedure.

Npe stock a large range of wellpoint pumps designed and proven to be the most effective for wellpoint dewatering activities. Npe are the wellpoint dewatering professionals. Operate the dewatering system continuously 24 hours a day until drain and structures have been constructed to fill material and until written by authorization to. Procedure of well point system.

By creating deep wells around the vicinity the groundwater is made to fall into them under the influence of gravity. Well point systems a well point system consists of a number of well points spaced along a trench or around an excavation site all connected to a common header which is attached to one or more well point pumps. In appropriate ground conditions a wellpoint system can be installed speedily and made operational rapidly. Well point systems and ancillary dewatering equipment can be hired for short and long periods of time and individually to cater to the clients dewatering requirements.

Well points are prepared at a distance of about 1m around the area to be excavated. Well point assemblies made up of a well point screen riser pipe and swing joint with tuning are generally installed by jetting. Deep well method of dewatering excavations just like the wellpoint method wells are drilled around the excavated area but the diameter of wells in this case varies between 150 200mm. Wellpoint dewatering is widely used for excavations of shallow depths especially for pipeline trench excavations.

This method uses the venturi principle where high pressure water is circulated through eductors in the base of each well to create a vacuum that helps promote drainage. Water is released at the rate of 20 to 25 liters per second at these well points which causes the soil to be dug and the well point to sink deeper into the ground. A wellpoint dewatering system consists of a series of shallow wells known as wellpoints which are installed at a pre determined depth and appropriate spacing around an excavation. Wellpoint dewatering is a simple yet efficient method of lowering the water table in excavations.

The eductor well method is a dewatering process used to control pore water pressures in materials with low permeability characteristics such as fissured clays or silts. The following procedure is adopted in the well point. The main header pipe is connected to a wellpoint dewatering pump and then discharged either to a designated point or through a water treatment system depending on water quality. A filter media of 3 16 inches 3 5 mm screened black sand shall be inserted around the 3 4 depth of the wells to act as barrier against fines and prevent choking of well points.