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Installation of the Correct Pump is Important for Borehole Efficiency

As the need grows for South Africans to investigate alternative ways of obtaining their water or, at least, to limit their current dependence on municipal supplies, many more are now seeking ways to protect themselves from the risk of drought and the steadily increasing municipal tariffs made necessary by shrinking reserves. Collecting rainwater could help, as could the recycling of grey wastewater. However, the best solution will most often be found beneath our feet in the form of underground aquifers whose content can be made accessible to consumers with the aid of a borehole and a suitable pump installation.

Whether any such aquifer is actually available to be exploited on the property of a prospective user, whether it may be of sufficient capacity, and for what purposes its contents may prove suitable must all first be determined. This will require a preliminary survey and, where favourable and after successful drilling, testing of the potential performance and quality of the newly exposed source must then follow. While the survey provides a good guideline, it is not always possible to predict exactly how deep it may be necessary to drill in order to reach the aquifer. The greater the depth of a borehole, the more power required from the pump installation to raise the water to the surface.

Much deeper and narrower than a well, on average, an aquifer should be intercepted at a depth of between 30 and 100 metres in most parts of South Africa. There are, of course, no guarantees and, in some instances, it could be necessary for engineers to drill as deep as 500 metres. The depth of a borehole together with that of any vertical pipework that may be used above ground, for example, to transfer the subtracted subterranean water to a storage tank, treatment plant or irrigation system is referred to as the system head and represents the total pressure that must be overcome by whichever borehole pump will be used in the installation.

While in other circumstances it may be fine to use a unit designed to operate above ground, these devices operate by sucking in liquid from one end and expelling it from the other, and this tends to limit their performance. Attempting to raise water from more than a few metres can result in air spaces within the flow. The effect is to cause irregular suction which presents as a phenomenon known as cavitation that, if allowed to continue, can cause severe damage to a pump’s structure. Instead, the models used where large heads of pressure are required are designed to operate when submerges and to force water up the shaft. For power and to avoid cavitation problems, they are considered essential for an effective and reliable borehole pump installation.

By now, it should be quite clear that prospecting and drilling for water is not exactly a DIY project. In practice, every aspect of the operation requires the attention of a team of experienced professionals. With a reputation for excellence backed by more than 13 years in the business, the Water Pump Group supplies and installs domestic, commercial, and industrial pumping systems that are sustainable and reliable. Contact us should you require more information or if you want us to do a borehole survey, drilling, pump installation, or water testing.