Thinking of drilling a borehole in Kenya? You might want to read this…

Boreholes are essentially the most basic sources of water in Kenya for companies, communities, and even individuals. Many people always ask, “Where do I start if I want a borehole in my homestead?” This article gives a brief of the steps and formalities to follow if you want to drill a borehole. Leave us a comment, we would like to hear more from you.

• Formalities :

1. Geological/Hydrological Survey to be done by Registered Geologist.
2. Getting Authorization from Water Resource Management Authority ( WRMA ) for drilling the borehole.
3. Conducting Enviornment Impact Assessment ( EIA ) & getting Licence from NEMA.
4. Getting No Objection Letter from Water Service Provider like Nairobi Water Company, Mavoko County Council etc.

• Actual Borehole Drilling Process :

1. Drilling of 11”until loose top formation & installing 9” temporary casing  then   Drilling 8” up to recommended depth.
2. Casing : Installation of 6” Casing pipe – Class – B ( 4.5mm thickness ) up to bottom . Generally ratio of Plain Casing & Screen casing is 70 : 30. but depends up on the hole drilled.
3. Gravel Pack : Inserting 2-4mm natural gravel outside the casing and inside the open hole for artificial filtration.
4. Borehole development : one need to do development by air jetting until water come out clean. Generally it is 3 hours but still depends up on the hole.
5. Well head Slab : on the top 1mtr x 1 mtr x 1 mtr ( LBH) digging pit & then making slab by using Cement, Send and gravel in proper ration which will prevent the hole by contamination. Some time client like to have a manhole which will be under ground with metal cover , so that place will look like flat .
6. Capping : fitting cap on the top until installation of pump etc.
7. Test Pumping the borehole : For the measuring exact yield of the borehole one has to do test pumping i.e. pump out water continuously 24 hours , then one can know the yield of the well and the rest level & pumping water level  etc. This is most important process to decide the size of pump.
8. Do Chemical & Bacteriological analysis via government chemist to know the water is suitable for the domestic / industrial use or not. Here’s a list of laboratories that can help with that.
9. Completion Report : preparing completion report ( Form 009 A ) as per WRMA rules & submit to the WRMA office as well as to the client.

• Installation of Pump for the borehole :

On the basis of test pump report one can decide the Pump Installation depth ,  and size of pump , motor, delivery pipe, cable , control panel, water meter and
other sundries.