Borehole Water

Finding alternative sources of water has become the buzzword of the day. Knowledge about boreholes is critical. For this reason, the most crucial question is, what are the costs of sinking a borehole?

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 the 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 of drilling a borehole, you 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, determine whether they have a good point or a borehole. This will give you a pretty good idea of the 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 can tell you the depths and conditions of your underground water.

• Geotechnical charts and scientific studies

You can look up geotechnical tables or experimental studies in your area. The latter will be a more expensive option, but it may shed some light on the aquifer’s depths and the composition of the ground.

2. Borehole Water

Borehole water is an effective way to use a natural resource. This is especially relevant for areas prone to droughts and off-the-grid living. Knowing how to tap into borehole water is essential.

Borehole water can be used in various ways on your property, including flushing toilets, washing machines, and running appliances.

Borehole water can be used as drinking water. Notably, the option is only possible once filters and other purification methods are 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 water sources due to changes in rainfall.

Purifying borehole water for drinking is costly. 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:

1. The depth of your water table, the composition of your ground

The water table can be as low as 3 – 4m in some areas. In other places, the water table can be 70 – 80m down. It depends very much on the natural composition of your site.

Usually, low-lying areas will have a higher water table. However, you would look at a much deeper water table on a mountain or hill.

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 where the water table lies between 1 – 10m. A well-point has a pump above ground to pump water to the required location. 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 between 10m and 200m. A PVC or metal casing is placed down the hole, and sand particles are filtered out through filtration media.

Installing a submersible (underwater) pump to pump the water to the surface is essential. The pump is placed at the bottom of the well and 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 drilled into the ground. It is usually about 250mm in diameter.

A 110mm heavy-duty casing is pushed down this hole. The case is metal or an alternative durable plastic substance. It has tiny slots cut into the pipe and is then moved into the hole. If the slots are too wide, the casing will fill with sediment.

Filtration media, such as river sand or silica, is placed in the pipe around this casing. The water is filtered into the tube. At the bottom of the Borehole, a submersible pump pushes water to the top.

Sometimes, soft sand can be problematic because the hole could continually cave in while the drilling occurs. However, various means can be used to counteract this.

6. How Deep Is A Borehole?

As we know, Borehole water is found at varying depths. Depending on the water table, your ground’s composition, what type of soil you have, and underground rock.

The rule of thumb usually is the deeper, the better. Depending on the water table and ground composition, this will give you a more constant flow.

If drilling into rock, you must find fractures allowing water to flow into the pipe. Usually, you must pass through various rock layers, clay, and other mediums 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, compressing the drilling head through the rock using compressed, high-pressure air. They pump water 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 the water contains sediment or other contaminants that need removal. You may need to filter the water 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

It is recommended to use reverse osmosis with salt water. In this process, the water passes through a delicate membrane under pressure, removing the sodium and chloride molecules.

The Presence Of Dissolved Solids and Metals

Removing metals from water can be done by running the water through an oxidising media, which will oxidise the dissolved solids flushing out of the oxidising media.

Ph Adjustment

Ph adjustment to neutralise water is crucial to inhibiting the corrosion of copper piping. The best option is circling the water through calcium carbonate or limestone media.

High Bacterial or E-coli Levels

UV lights destroy living organisms in the water, such as bacteria and E. coli. The ultraviolet light spectrum is strong enough to kill any living organism in the water.

Other filtration methods include activated charcoal filters (which remove the earthy taste and smell from the water) and sediment filters that range between 1 and 50 microns.

Parts of living in this day and age require a shift in how we view and utilise water. We must be mindful that although water is a renewable resource, it must be employed 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! A borehole and solar panels would be perfect for an off-the-grid home.