The City of Tshwane has resumed chlorinating the water supply in Bronkhorstspruit, but residents are still being warned against using the water for drinking, cleaning or washing.
The Department of Water and Sanitation says the chlorine-related problem has been resolved and that new water entering the system is being treated.
However, potentially contaminated water may still be present in reservoirs and pipelines. The system must be thoroughly flushed before the water can be declared safe for use.
Residents have also been urged to clean containers previously used to store the potentially contaminated water with ordinary household detergent before reusing them.
Water infrastructure expert Gundo Maswime from the University of Cape Town has warned that consuming untreated water could have serious health consequences.
Maswime says pathogens in contaminated water can cause illnesses such as gastroenteritis, cholera, typhoid and dysentery.
He suggested that Shigella could be responsible for the gastroenteritis cases reported in Bronkhorstspruit, although further investigation would be needed to identify the specific pathogen.
Maswime warned that while the current outbreak has been associated with gastroenteritis, the consequences of inadequate water disinfection could have been far more severe.
More than 400 people have reportedly been affected by gastrointestinal illness in the area, with the City of Tshwane's failure to chlorinate the water supply blamed for the outbreak.
Meanwhile, the Economic Freedom Fighters (EFF) and the Democratic Alliance (DA) are expected to open criminal cases against Tshwane Mayor Nasiphi Moya and the city manager over the failure to chlorinate the water.
The water safety warning remains in place as authorities work to flush the system and ensure the supply is safe for residents.