Defining the necessary flow rate is very important for any water well project. It will very much depend on the intended purpose, namely if it is for public, industrial or private consumption.

When the superficial layers are too soft, there is the need to temporarily contain the borehole’s walls, in order to ensure its stability during the drilling process. This problem is solved through the installation of a steel casing with a diameter that allows drilling along its interior. In specific cases of abstractions in which it is essential to protect surface waters from the presence of brackish or chemically aggressive water, it is necessary to insulate the abstraction by cementing the borehole until the desired depth, thus avoiding the contamination of the aquifer.

In order to insulate productive formations from initial permeable formations it is necessary to apply a layer of an impermeable material, such as clay or a similar material.

In productive formations there is the need to create a filter pack, usually comprising calibrated gravel with a constant grain size, in order to control the water entry speed and prevent the washing of fine-grain materials. Its thickness must be calculated according to the characteristics of the water well.

Given that, in most cases, the hydrodynamic level is at depths greater than 10m, it is usually necessary to equip the abstraction with a submersible pump and the corresponding extraction column. The choice of the submersible pump depends on the flow rate and on the static and hydrodynamic levels. We must also take into account that the pump’s size may be conditioned by the casing’s diameter.

The permanent piping system may be made of PVC, Steel or Stainless Steel. The piping system’s diameters depend on the borehole’s diameter and will restrict the pump’s diameter. In the productive areas of the water well, the pipe has a screen system whose purpose is to allow and control the entry of water into the abstraction system. The well screen system depends on the material used. The screen may be slotted by cutting wheel, bridge-slotted or slotted wire-wraped (Johnson’s screen type). The open area will depend on the type of inlet, the material’s strength and the well screen characteristics.