The Gambia has abundant surface water in the Gambia River. This is rarely used for drinking water due to poor water quality. In addition, the rainfall is very seasonal and there are no inland rivers. That means that the Gambians are dependent on groundwater for their drinking water
Traditionally the Gambian draws from the upper water layer with hand-dug wells. This water is highly contaminated and not drinkable. Moreover, such a well is open and unsafe for children and animals.
Deeper aquifers are pure. It is from the second water layer, which is about 15 to 30 m below the first layer, that we pump water. This water layer is of good quality, is bacteriologically pure and is sufficiently replenished in the rainy season.
To reach the second water layer, we drill a well by machine. A tube with a diameter of 12.5 cm is placed in the well. We fill the space around the well. So the first contaminated water layer will not contaminate the second layer.
A long, narrow water pump enters the tube. The water pump is at the bottom and pushes the water upwards. Depending on the available power, the pump has a flow rate of 1000 to 3000 liters per hour.
The pump operates on direct and alternating current and can switch from electricity generated by solar panels to the electricity grid without adjustments.
The pump and the drilling of the pump well are the biggest costs of the water installation. We opt to use high-quality materials. In this way we are sure of a long service life and we limit maintenance.
Two or three solar panels provide electricity for the pump. As soon as the sun shines, the pump works. Above the well is a tower with a water tank of 1000 liters. After sunset, the pump stops and the water from the water tank can still be used.
When the water tank is full, the water runs back into the well. This way no water is lost and the water stays fresh.
We place the water tank about 3 meters high on an iron tower next to the central distribution point. If we want to transport water over longer distants, we will place a tower of 7 meters height.
Next to the tower is a first distribution point. We draw pipes for additional distribution points. In this way a village gets access to pure water.
We choose the location of the borehole in consultation with our local employees and local people. That can be at a remote village or near a school or health center.
Local employees maintain installations. Taps are being replaced, pipes are being repaired.
So far we have installed 23 wells in 20 villages with the corresponding distribution infrastructure. In this way we provide thousands of people with pure water.
The immediate consequences of these projects are a noticeable drop in disease and death rates, both among children and adults. Thanks to the water, we also see new local initiatives emerging, such as the creation of vegetable gardens.