Experiencing a severe drought forever changes the way you view water and its usage. Gone are the days of mindlessly opening a tap and letting it run unheeded. Relying on the council alone to supply water is out of the question; as a result, borehole water has become very popular.
Finding alternative sources of water has become the buzzword of the day. Knowledge about boreholes is critical. For this reason, the most crucial question of all is what the costs of sinking a borehole are?
So what does it cost to sink a borehole in Cape Town?
A borehole can vary in price anywhere from R50 00 to R180 000. Depending on the following factors:
- The area in which Borehole is being drilled
- Conditions of the rock
- The depth of the aquifer
- Amount of casing and filter media required
- The specifications of the submersible pump
- Difficulty accessing the site/crane hire
Drilling out of season may lower the costs as the borehole contractors may be less busy than in summer.
Once you have a better idea of the cost involved in drilling a borehole, one can make a more informed decision.
How Do You Know If Your Property Has Water For Boreholes?
The most crucial question is, DOES YOUR LAND HAVE WATER THAT IS ACCESSIBLE. It’s critical to find out how to know if your property has water.
There are three ways in which you can find out if your property has water suitable for a borehole:
- Check with your neighbours.
If your neighbours have accessed their underground water, find out from them whether they have a well-point or a borehole. As a result, you will have a pretty good idea of water depths in your area.
- Contact a well-established borehole contractor
You can contact a well-established borehole contractor and ask them. They will usually have an excellent understanding of the areas where they work regularly. They will be able to tell you the depths and conditions of your underground water.
- Geotechnical charts and scientific studies
You can look up some Geotechnical tables or experimental studies of your area. The latter will be a more expensive option. However, it may shed some light on the depths of the aquifer and the composition of the ground.
2. Borehole Water
Borehole water is a very effective way of utilizing a natural resource. And is especially relevant for areas prone to droughts and off-the-grid living. As a result, knowing how to tap into your borehole water is essential.
Borehole water can is used in various ways on your property. It can be used to flush toilets, run your washing machine and with various other appliances.
Borehole water can be used as drinking water. Importantly the option is only possible once you have had filters and other purification methods installed. These purification methods include the following:
- Installation of filters
- UV Treatments
- Bacterial control using chlorine and various other methods
With the advent of climate change, many people are looking for alternative sources of water due to changes in rainfall.
It is costly having borehole water purified for drinking. However, in some outlying areas, this is the only option for clean drinking water.
3. What Is The Borehole Depth For An Average Home?
The depth of a borehole for an average home depends on two things:
- the depth of your water table
- the composition of your ground
In some areas, the water table can be as low as 3 – 4m. In other areas, the water table can be 70 – 80m down. It depends very much on the natural composition of your area.
Usually, low-lying areas will have a higher water table. However, if you are on a mountain or hill, you would be looking at a much deeper water table.
4. What Is The Difference Between A Borehole And A Well-Point
The depth of your water table will determine whether you need to install a well-point or a borehole.
A well-point is installed in an area where the water table lies between 1 – 10m. A well-point has the pump above ground to pump water to the required area. The water is sucked up through a pipe in a filtration media. It is a far cheaper alternative.
In contrast, a borehole is drilled when the water table is found at a depth between 10m – 200m. A PVC or metal casing is then placed down the hole as well as a filtration media to filter out sand particles.
Installing a submersible (underwater) pump to pump the water to the surface is essential. Placed at the bottom of the well, and it pushes the water up to the surface. Drilling a borehole is a more expensive option.
5. How Do Boreholes Work?
A borehole is a hole that is drilled into the ground. The hole is usually about 250mm in diameter.
A 110mm heavy-duty casing is pushed down this hole. The casing is metal or an alternative durable plastic substance. It has fine slots cut into the pipe and is then pushed into the hole. If the slots are too wide the casing will fill up with sediment.
All around this casing, filtration media is placed around the pipe. Filtration media is river sand or silica, and it filters the water into the tube. At the bottom of the Borehole is the submersible pump which pushes water to the top of the Borehole.
Sometimes soft sand can be problematic in that the hole could be continually caving in while the drilling is taking place. However, there are various means of counteracting this.
6. How Deep Is A Borehole?
As we know, Borehole water can be found at varying depths. Depending on the water table, the composition of your ground, what type of soil you have, and underground rock.
The rule of thumb usually is the deeper, the better. This will give you a more constant flow, but again, this is dependent on the water table and ground composition.
If you are drilling into rock, you will need to find fractures in the rock which will allow water to flow into the pipe. Usually, you have to go through various rock layers and clay and different types of medium until you reach the water table.
7. Types Of Borehole Drilling Methods
Boreholes are usually quite expensive to drill due to the drilling heads used. Some of these heads are diamond-tipped, and others have powerful metal heads designed to cut through rock.
Compressors are also used which compress the drilling head through the rock using compressed, high-pressure air. At the same time, water must be pumped down to lubricate the diamond heads and push the media out of the top of the hole.
7. Borehole Filters
It is beneficial to add filters to your Borehole if there is sediment or anything in the water that needs to be filtered out. You may need to filter it to use it for irrigation or drinking water.
The type of filtration required will depend on what you want to use the water for.
There are different types of filtration for various requirements. Some of these requirements may include:
- high salt levels
- the presence of dissolved solids and metals
- water that requires ph adjustment
- high bacterial or E-coli levels
High Salt Levels
With saltwater, it is recommended to use reverse osmosis in which the water passed through a fine membrane under pressure. Thereby removing the sodium and chloride molecules from the water.
The Presence Of Dissolved Solids and Metals
Removing metals from water can be done through running the water through an oxidizing media which will oxidize the dissolved solids. These will then be flushed out of the media.
Ph adjustment to neutralize water is crucial so that you inhibit the corrosion of copper piping. The best option is by circulating the water through a calcium carbonate or limestone media.
High Bacterial or E-coli Levels
UV lights are used to destroy any living organisms in the water as in bacterias and E-coli. The ultraviolet light spectrum is strong enough to kill any living organisms in the water.
Other methods of filtration include activated charcoal filters (which removes the earthy taste and smell from the water) as well as sediment filters which range between 1 and 50 microns.
Part and parcel of living in this day and age require a shift in how we view and utilize water. We need to be mindful of the fact that although water is a renewable resource, it needs to be utilized with care.
Boreholes give you an excellent alternative to local council water, which has become expensive. They also add value to your property overall.
Having a borehole is a winning idea all around!