A borehole is a narrow shaft bored in the ground, either vertically or horizontally. A borehole may be constructed for many different purposes, including the extraction of water, other liquids (such as petroleum) or gases (such as natural gas), as part of a geotechnical investigation, environmental site assessment, mineral exploration, temperature measurement, as a pilot hole for installing piers or underground utilities, for geothermal installations, or for underground storage of unwanted substances, e.g. in carbon capture and storage.

In Nigeria, this is the preferred method for obtaining freshwater needed for both domestic and industrial purposes. This is preferred over antiquated metnods like well and surface drainages. Water from boreholes are also prefered because of the biological film that grows naturally on the surface of sand called the Schmutzdecke. This acts as a natural filter as greatly improves the quality of water found within the earth.

Of course, there are situations in which the water gotten from a borehole isn't of good enough quality for consumption. For this reason, Omisej also provides robust Water treatment Services to improve the quality of the water.