How To Combat Iron Bacteria In Boreholes

Strange-looking borehole water has led to many a perplexing moment for landowners; in many cases this phenomenon can be attributed to iron bacteria.

- Gert Nel

Borehole users in the Eastern Cape often find that their water has a reddish colour and slimy appearance. The yield of the borehole also tends to decrease, even if rainfall levels remain unchanged. Once the borehole pump is pulled out, it is found to be covered in a hard, reddish layer. Tests performed on this type of water have revealed that the groundwater contains iron bacteria and, although still drinkable, the red discolouration limits its use.

Iron bacteria bind dissolved iron or manganese to oxygen, forming an undissolved ferric iron compound that causes deposits and bad odours. Over time it can clog the casing of the borehole. This reduces the yield, because the flow of groundwater is restricted. It can also lead to blockages within the distribution system.

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