Earthy-tasting water is safe to drink

Residents who have detected an earthy flavour to their tap water are reassured that it remains safe to drink and compliant with SANS241 standards.

The change in taste is due to the presence of geosmin in the raw water supply, the City of Cape Town said in a statement. They emphasise that geosmin poses no threat to human health and is a naturally occurring organic compound and is responsible for the earthy taste of beetroot and the scent that occurs in the air when rain falls after a dry spell. The compound is sometimes present in water, particularly during periods of hot weather, and even minute concentrations of a few parts per trillion can be detected by the human palate, said the statement.

The City said they are currently experiencing high levels of geosmin in raw water supply from the Theewaterskloof Dam. This is currently affecting the taste and smell of the water supplied from the Faure and Blackheath water treatment plants to various areas across Cape Town, primarily the central and southern regions.

The City is monitoring the situation as part of the water treatment process, which is currently enhanced by the dosing of powdered activated carbon during this process to reduce the effect of the geosmin. However, it may take some time for the taste and smell of the water to normalise.