The drilling of borehole for groundwater supply entails three phases namely:
b. Drilling and construction
c. Pump acquisition and installation with transmission pipes to an overhead storage tank.
PHASE 1: Exploration or hydro- geological investigations:
The initial stage involves conducting detailed hydrological investigations to locate suitable aquifers (water bearing rocks) capable of yielding substantial quantity of groundwater, using geophysical techniques. Prospective sites for borehole drilling are selected at early stage.
PHASE 2: Borehole Drilling, construction and development:
The second phase involves drilling, construction and development of the borehole provided the result of phase1 is proved positive and a site has been selected. Activities under this phase comprise the following:
• Borehole test drilling, construction and development
• Pumping test to determine the aquifer characteristics which include the sustainable yield of the borehole and the depth of the pump installation.
• Water sampling and water quality assessment to determine the quality of the water for intended use.
• Paid or apron construction are required.
PHASE 3: Pump Acquisition and Installation:
After a successful drilling, construction and development of the borehole, the appropriate submersible pump and accessories are acquired and installed on the borehole. Pipes and cables are connected from the pump in the hole to an overhead storage tank where the ground water will be used as flow by gravity to the points of use. This phase also involves some plumbing works to connect pipes to the storage tank.