ARTICLES

Typical Borehole Testing Services and the Reasons They are Necessary

The existence of underground streams or aquifers has been known for millennia. In fact, there is abundant archaeological evidence that, as early as the Neolithic period between 7 000 and 10 000 BC, primitive humans were already constructing wells in order to gain access to these subterranean sources of life-sustaining water. The practice made possible the development of farming and, with it, the growth of fixed communities in which the village well was often a site for its members to socialise and to trade. Unlike a modern borehole, wells were dug, not drilled, and no testing services, beyond the simple act of tasting the water, would have been undertaken or even considered necessary.

The shafts of these early wells were generally lined with wood or wickerwork to limit contamination from the surrounding soil and the main threat to water purity was animal and human waste left to permeate the soil. Given the infinitely greater number of both people and animals in existence today, as well as the vast amount of industrial activities with their own toxic contributions, the potential hazards to water purity are manifold. As a result, the product of our modern version of the primitive well or borehole is subject to rigorous testing services, while a good deal more care must now be taken regarding the choice of a suitable site and its subsequent excavation.

The drilling process can be a costly one, so ensuring a site that is likely to yield water of suitable quality and sufficient quantity is important. It is therefore also important that the prospecting is undertaken by an experienced hydrogeologist who will consult the lay of the land and, with the help of data from geological maps of the area, estimate the depth at which the aquifers is likely to be found and identify the best point at which to commence drilling the borehole, Some testing may prove necessary at this stage and services could include chemical screening of the soil around the proposed site for signs that sewage or industrial waste from any possible sources nearby may have infiltrated the area.

These modern wells no longer rely on wood or wicker to line the shaft. Instead, all risk of soil entering the effluent stream is countered by the use of a tubular lining made from stainless steel which will extend from the surface down into the bedrock through which the aquifer is flowing.

Depending upon its intended use, the quality of groundwater required varies. In general, with few exceptions, high concentrations of dissolved solids are present in borehole water and so testing services are necessary to identify these, along with any microorganisms that are also present. The results provide the information needed to identify the appropriate steps to remove them, which is especially important when a potable supply is required.

Some chemical treatments in conjunction with filtration to remove organic and inorganic particles, followed by reverse osmosis to polish the final effluent should normally do the trick. Other investigations employ pressure measurements to estimate flow rates and long-term yield. A supplier of water purification equipment and skilled in all aspects of borehole technology, the Water Pump Group has the experience and specialised knowledge to perform testing services for commercial and domestic clients.