The Council for Scientific and Industrial Research (CSIR) confirmed on Thursday that the water at Stinkwater, in Hammanskraal, was not suitable for consumption.
This was revealed by researchers after the CSIR commissioned a three-year study in the area.
Most residents of Stinkwater relied on underground water due to a shortage of taps in the area.
CSIR senior researcher and water scientist Wouter le Roux said 144 samples were tested.
“From our side, all we can say is that there are certain illnesses associated with drinking that water. We did advocate for things like using Jik for water chlorination to at least kill the germs in the water,” he said.
Le Roux said by law, water should be tested daily to ensure that it was good for human consumption. He said untested water could be fatal for infants.