Category Archives: New constructions

Understanding one of the main causes of wells’ drying in Sierra Leone, through an analysis of a water table movements.


Season well (getting dry in dry season with water table movements)

Why hand-dug wells should only be dug in a specific period of the year, corresponding to low aquifer level?

From a technical point of view, hand-dug well drying is often due to the fact that the pumping system does not draw deeply enough or that the well itself has not been dug enough. This is typically the case of structures dug outside of the low water level period, so the bottom of the column dries up with the movement of the water table during the dry season.

An analysis of 29 consecutive months records, collected to measure the variations of the water table level in relation with the rainfall evolution, clearly illustrated the importance of timing the sinking of a well to correspond to low aquifer levels. icon_pdf

Water quality monitoring: protocol for tracking coliforms,_original.jpgColiform bacteria are a commonly used bacterial indicator of sanitary quality of foods and water. They can be found in the aquatic environment, in soil and on vegetation; they are universally present in large numbers in the faeces of warm-blooded animals, and their presence is used to indicate that other pathogenic organisms of fecal origin may be present.

Therefore, after a campaign of new water points construction or for rehabilitation, Inter Aide is doing water analysis to confirm that the water is safe for drinking and that the improved water point will prevent people to be affected by water related diseases. kits (such as DelAgua kits)[1]that allow simple and reliable measurements that can be done on site or in a local simple laboratory (clean dedicated room).

[1] Other devices than Del Agua kits can be used such as Potatest (Wagtech).


Picture of a Petri Dish culture with development of thermotolerant coliforms : what we want to avoid !

The following note in the link hereafter is the protocol Inter Aide is using to proceed to bacteriological tests. icon_pdf

Security rules for hand-dug wells constructions or rehabilitations

The document in link lists general guidelines and advises for ensuring security, both for workers and villagers, while hand dug well construction. icon_pdf

Jamal security

Jamal, who is also hand pump technician, is working as contractor for well construction. He’s always using equipments such as helmet and harness attached to a security rope fixed on top, to go inside wells.