What you need to know about installing a borehole

6 Oct 2016

What do you need water for? To irrigate your garden and top up the swimming pool? To provide household water to a small rural community or farm household? Or maybe even to service a multi-hectare irrigation scheme.

Borehole construction includes the mobilisation of equipment to the site and back to the base, drilling per metre, casing entailing supply and installation of solid casing and screen, gravel pack, sanitary seal and well-head construction.

Whatever your requirements are, nothing beats a source of cost-effective water right where it’s needed. And in most cases, that solution is a borehole. But drilling a borehole requires some research and planning.

The Borehole Water Association (BWA) shares some insight about boreholes…

The costs of installing a borehole

According to the Borehole Water Journal Online Vol 103, homeowners who are looking to have a borehole installed on their property should factor in the following expenses…

1. Site selection, which is used to determine whether and where to locate a groundwater production borehole.

2. Borehole construction. This includes the mobilisation of equipment to the site and back to the base, drilling per metre, casing entailing supply and installation of solid casing and screen, gravel pack, sanitary seal and well-head construction, and well development entailing cleaning of the borehole after construction.

3. Pumping test cost for post-construction assessment of borehole and aquifer performance.

Homeowners do not have to register their boreholes if they plan to use the water for small gardening.

4. Hydrochemical analysis cost of water quality testing for an intended use.

5. Installation cost for a pump and/or potable water storage tank and reticulation system.

6. Maintenance costs for annual checks to the pumping equipment, pipe work and repairs should there be any failures.

7. Electricity costs for running the pump each time it is switched on.

Do I need to register my borehole?

According to the National Water Act, you don’t have to register ground water use if it is to be used for domestic purposes only.

Homeowners do not have to register their boreholes if they plan to use the water for…

- Reasonable domestic use in a person’s household

- Small gardening (not for commercial purposes)

- The watering of animals (not for commercial purposes)

If all the boxes have been ticked, a 20-year life for the major components can be expected.

Borehole water can also be used for recreational activities like filling up a swimming pool and household emergencies such as putting out a fire.

Where to drill the borehole?

Most residential stands are ringed by palisade fencing or brick walls. Just getting a 25 tonne drill rig onto the property can be difficult to say the least. In quite a few cases, there are two choices, the start of the driveway or the middle of the driveway.

So keep in mind that you may need to do some deconstruction work to allow the drill rig to access your property, and then once the borehole has been drilled, some building work may be required to restore the area. This will not be included in the drilling costs.

While this is a hassle, the reality is that borehole drilling will involve some mess, and so it’s better to plan for it than to get a nasty surprise. Discuss this with the drilling contractor and make sure that they can offer a solution that is both practical for your property while still giving the borehole the best chance of success.

What if the driller doesn’t find water?

A borehole installation can cost anything from R60 000 to R100 000, but can cost more depending on how deep you need to drill, the amount of casing used, type of rock that needs to be drilled, ground conditions, equipment and other purpose-for-use related costs.

Your agreement with the driller will be to drill a hole in the ground, with the possibility of tapping into a sustainable source of water. If good siting procedures have been followed and in the unlikely event that the hole was found to be ‘dry’, you’ll still be required to pay the contractor for the drilling.

However, you will not be required to pay for any materials and equipment that would be required for a complete installation, namely the pump, piping and electrics.

These items are a function of the amount of water available or required, and can only be selected once a test has been done on the yield potential of the hole. Essentially, no water means no pump and related equipment is necessary.

What kind of borehole pump will I need?

You may wish to have a second contractor select and install a pump and ancillary equipment or your driller may be in a position to offer a turnkey service.

Pumps fit into three categories: too big, too small or just the right size for the job. Good selection and years of trouble-free operation starts with reliable borehole data gathered from the yield test. Be careful of “this month’s special, a 0.75kW pump for only…”. The chances are good it’s totally unsuited for your application.

Get your contractor to explain the capabilities of the pump and the controls and protection devices they have installed. An informed end user will be able to recognise the first signs of potential problems and call in qualified help before things get too expensive.

The electrical side of the installation must be done by a qualified electrician who is trained or well-experienced with groundwater installations. Your borehole is an integral part of the electrical system of the property and must form part of the Certificate of Compliance (COC).

How long will a borehole last?

If all the boxes have been ticked, a 20-year life for the major components can be expected.

Is a borehole a good investment?

A borehole installation can cost anything from R60 000 to R100 000, but can cost more depending on how deep you need to drill, the amount of casing used, type of rock that needs to be drilled, ground conditions, equipment and other purpose-for-use related costs.

The trouble is there is no guarantee you will find water, so you could risk paying many thousands for drilling without a successful outcome.

However, having a borehole will add significant value to your property and over a period of time, it will represent a good investment. This assumes that the installation has been done by professionals and with due care.