ALL ABOUT DRILLING
Do you want a borehole but unsure about whats involved in the process? There are many misconceptions about the drilling process but we want to show you what the steps are so you can move forward with a feeling of confidence.
Step 1 – Hydrological Survey
The first thing that needs to be determined is where the water is and the best location to drill. To do this, a licensed geologist needs to come to the prospective borehole site. The geologist will use a special machine to take readings of the ground formation which will guide in the decision of selecting the best place for drilling. We would be happy to recommend a reputable geologist and take care of this entire process for you.
Step 2 – Government Approvals
There are several approvals required before drilling can begin. One is the Authorization to Drill issued by the Water Resource Management Authority, the other is an Environmental Impact Assessment and approval authorized by the National Environmental Management Authority. In some cases, a Letter of No Objection from the local water supplier is also necessary.
The application requirements for the government approvals are as follows:
Water Resource Authority Application
Environmental Impact Assessment
Name of landowner
KRA PIN certificate copy
Title deed copy
Incorporation documents (for organizations and businesses)
Physical location details of borehole location and landowner
We know that getting these approvals can be overwhelming, thats why we offer approval procurement services. We would be happy to arrange these approvals for you.
Step 3 - Drilling
Once the hydrological survey is done and the all the required governmental permits have been issued, the drilling can begin.
Drilling is done using a powerful machine called an Air-rotary Rig. This rig is able to penetrate many types of soil and hard rock. The hardness of the rock determines the amount of time it takes to reach the desired depth. Once the drilling is finished, it's time to install casing. Casing is installed into the newly drilled hole to keep it form collapsing. The type of casing used can be either PVC or steel depending on the ground formation and depth of the borehole. In some situations where very hard rock is encountered casing is not used except in the higher sections of soft soil, this helps the borehole to yield more water in poor water bearing aquifers. There are two parts of the casing in any borehole, one is called "plain" the other is called "screen". the "plain" is simply normal pipes, while the "screen" is pipes with many slots cut into them which allows water to enter the pipe. The "screen" is placed at the depths where water is entering the borehole. Different boreholes require different amount of "screens".
Once the casing is installed, gravel-pack (small rocks) is poured around the outside of the casing pipe to fill the space between the hole wall and the casing. This gravel-pack helps to ensure that the water entering the casing screen comes in as clean as possible.
The final part of the drilling step is well-development. Well-development is important to ensure that all mud and particles are removed from the borehole so the borehole functions properly. Development is done using the air-compressor on the rig to flush the water and particle mixture out until the water begins to become clear.
Step 4 - Test-pumping
It is important to know the borehole's yield so that the correct pump can be selected and installed. To determine this we do test-pumping. This means that a pump is installed into the borehole and connected to power, we then pump, measure the amount of water coming out, and take depth readings of the water level. This involves pumping borehole water for a fixed set of variables; a given time at a given rate, and then assessing the test’s impact on the water level in the borehole. When this testing is finished, the pump is removed and a report is compiled. At this point we can recommend a suitable pump to install.
Contrary to popular belief, an endless supply of water won’t just surge to the surface following the drilling of the borehole. A pump has to be installed and connected to electricity supply.
Step 5 – Equipping the borehole with pump and pipes
The kind of pumping system and piping installed in the borehole will largely depend on the intended use, the yield, and the depth of the borehole. Solar systems or regular electric power systems can be installed depending on the needs. The equipping part is generally not done at the same time as the drilling and the costs associated with it are not related to the drilling costs.
We can also construct and integrate water storage tanks and elevated towers to meet your requirements.
For more information feel free to contact us: