Water is primarily pumped from a borehole using submersible borehole water pumps inserted to extract water.
Boreholes are specialized, narrow, and deep vertical shafts drilled into the ground to access underground water sources. Because these holes are often very deep and the water level can be far below the surface, standard surface pumps are usually not effective. This is where submersible pumps come into play.
A submersible borehole water pump is a pump that is designed to be fully submerged in the water within the borehole. It is connected to a power source via a waterproof cable and to the surface via a pipe. The pump itself contains the motor and the pumping mechanism (impellers or screws).
When the pump is activated, the motor drives the impellers or screw, which draw water into the pump intake. The water is then pushed upwards through the pipe to the surface. The weight of the water column is supported by the submerged pump and the power is transmitted electrically, making it efficient for lifting water over significant vertical distances.
Key Aspects of Borehole Pumping
Understanding the process involves several key components and considerations:
- The Borehole: This is the deep, narrow hole drilled into the ground to reach an aquifer (an underground layer containing groundwater). The depth varies depending on the local geology and water table depth.
- The Submersible Pump: As highlighted in the reference, submersible borehole water pumps are inserted into the borehole. These pumps are specifically designed to fit within the narrow diameter of the hole and operate while submerged.
- Power Supply: The pump motor requires electricity, delivered via a submerged, waterproof cable from a power source at the surface (mains power, generator, or solar panels).
- Rising Main Pipe: This is the pipe through which the water travels from the submerged pump up to the surface storage tank or distribution system. It must be strong enough to support the weight of the water column and the pump itself (if suspended from it).
- Control System: A control panel at the surface manages the pump's operation, often including motor protection and level sensors to prevent dry running.
Why Use Submersible Pumps?
Using submersible pumps for boreholes offers several advantages:
- Efficiency: They push water upwards rather than pulling it from the surface, which is more energy-efficient for deep wells.
- No Priming Required: Since the pump is already submerged, it is naturally primed.
- Reduced Noise: The pump operates silently underwater.
- Durability: Designed to withstand submersion and often harsh water conditions.
Applications of Borehole Pumps
According to the reference, borehole pumps are versatile tools used in various applications:
| Application | Description |
|---|---|
| Water Supply | Providing potable or non-potable water for domestic, municipal, or industrial use. |
| Reducing Groundwater Levels | Dewatering construction sites or controlling groundwater levels for drainage. |
| Sprinkler Irrigation | Supplying water under pressure for agricultural or landscape irrigation systems. |
| Pressure Boosting | Increasing water pressure in distribution systems. |
| Geothermal Systems | Circulating water or fluid in ground source heat pump systems. |
These applications demonstrate the crucial role that effective borehole pumping plays in managing and utilizing groundwater resources.
In summary, water is extracted from a borehole by lowering a submersible pump deep into the water table. The pump's motor then pushes the water up through a pipe to the surface, powered by electricity supplied from above ground.
