Borehole Drilling

Drilling for water is a highly skilled and specialist skill

Borehole drilling requires highly trained surveyors, drillers and engineers. TASTE has an experienced team able to provide the highest possible quality of service across Plateau State and throughout Nigeria.

TASTE is the proud owner of three drilling rigs enabling us to drill down to 200 metres below ground if needed and through a wide range of geological conditions including sand, mud and rock. In Plateau State, where the majority of our projects take place, we typically find water within 30-100 metres. However, further afield, we are likely to have to drill close to our maximum capacity before encountering decent volumes of water.

Before drilling begins, an appropriate site is selected based on various factors such as geological surveys, hydrogeological studies, and consultation with local communities. The goal is to identify areas with the highest potential for groundwater availability. Having conducted a geological survey to ascertain the most suitable point for a borehole, our drilling team get started.

Drilling operations: The actual drilling process begins with the setup of the drilling rig. The rig is used to penetrate the ground and create the borehole. The drilling process involves rotating the drill bit while applying downward pressure to break through the rock or soil layers.

As the drilling progresses, the borehole is lined with casings – the big blue pipes you see in the picture –  to prevent its collapse and maintain the integrity of the well. The casing also helps to  prevent contamination between layers.

As work continues, the team are able to determine the geological structure they are drilling by examining the cuttings (the material that is flushed to the surface by the drilling process).

Having reached the depth recommended by the geologist, the team use compressed air to flush the hole and then check that it fills quickly enough with water. If they are happy, they use a clay powder to stabilise the hole (by adding it to water and pouring it around the blue pipes as a sort of glue) and then hand over to our pump technicians.

Pump installation: Once the borehole is functioning, a suitable pump system is installed to extract water from the aquifer. The type and size of the pump depends on the anticipated water demand and the characteristics of the aquifer. For boreholes up to around 30m deep, a hand pump will often suffice.

For deeper water sources a powered pump is required. In recent years we have moved away from diesel pumps to the use of electric pumps powered via solar panels. Although there is a higher initial capital cost with solar panels, they require minimal maintenance and avoid the need to purchase fuel as well as the health and environmental issues associated with the use of diesel fuel. The pump is used to fill a “header tank” of 5000-25,000 litres capacity during the day enabling provision off clean water throughout the 24 hours.

Well maintenance and monitoring: Regular maintenance and monitoring are crucial to ensure the longevity and sustainability of the well. This includes periodic inspections, cleaning, and repairs if necessary, as well as monitoring the water levels and quality over time.

Our pump technicians work with local masons to cast a platform for the hand pump. However, before they do that, they need to insert lengths of solid steel rod inside the blue casings. The solid steel rod is about half inch in diameter and connects the piston assembly in the pump cylinder to the pump handle.

Operation of the pump handle moves the pump rod and the piston assembly up and down opening the non-return valve to allow water to flow in one direction. The handpump draws the water up the pipes and out to the waiting public.