How SWS Filtration’s Techniques can Improve Water Supplies.

Over the centuries much effort has been made to improve the quality of domestic water supplies. As countries develop a priority is to provide safe drinking water for everybody. In Britain most people now have clean water piped directly into their homes; private water supplies drawing from springs or boreholes are comparatively rare, and few if any use hand pumps for their domestic water supplies.

In rural parts of Africa the situation is entirely different. Springs, streams and water holes are still an important source of drinking water and often the water is used totally untreated. Where this is still the case, SWS Filtration have introduced various simple techniques to improve both the quality of the water that can be drawn from these sources and people’s access to it.

Here are some examples...

Hillside springs can often be protected quite easily because the water can be piped to a convenient collecting point by gravity. If the springs emerge in the valley bottom and there is nowhere lower for the water to run this is not possible so to avoid having to scoop the water out by hand it can be drawn with a suction pump such as the SWS Rower Pump. If the latter option is possible then the water can be poured directly into the people’s containers without dirty containers being dipped into the water. See Illustration

Sub-sand intakes. In areas where streams or rivers with sandy beds are a common source of water SWS Filtration have introduced ways of drawing water through the sand so that it is pre-filtered and most of the contamination is excluded. Click here for more information about sub-sand intakes

Open hand dug wells are still very common. Provided they are carefully maintained and clean buckets are used to draw the water they may be a satisfactory water source but many projects prefer to cap the wells and install hand pumps so that the water can be drawn directly without risk of contamination. The SWS Rower Pump is ideal for use on wells less than six metres deep but where the wells are slightly deeper the NZ Pump may be used if the demand is not excessive. A major section of this SWS web site is dedicated to Rower Pumps. To go to this section click here Where wells are used by very large communities more robustly engineered pumps may be more appropriate. (Please email SWS Filtration for details).

A more difficult problem to solve is where irrigation canals are also used for domestic water supplies because by definition they cannot have sandy beds and frequently they are infected with parasites such as bilharzia. The only option here may be to create large sand filters through which the water may be filtered before it is used. SWS Filtration has collaborated in projects where this has been done and if you email us we will be pleased to give you references to follow up.

Well-jetting is particularly suitable for sandy river beds, wadis or river banks where water can be found close to the surface. It is a simple technique for inserting small diameter wellscreens into shallow sandy water bearing aquifers. Unlike conventional boreholes which require heavy drilling equipment, well-jetting is carried out by hand using just one or two portable engine pumps to produce a powerful jet of water. More information on Well-jetting can be found here