The city made oral submissions at the South African Human Rights Commission on Wednesday, saying they aren’t liable for how raw sewage spillage into the river.
Various institutions and surrounding municipalities have also denied being behind the contamination.
The inquiry began in September following a commission’s site inspection which exposed a violation of the right to access to clean water a clean environment and human dignity.
The commission’s Philip Molekoa said that no one has come forward to claim responsibility for the contamination.
“None of the institutions have done that.”
Meanwhile, the South African National Defence Force has deployed army engineers to the Emfuleni Local Municipality to help restore capacity to failing water treatment works and stem the flow of raw sewage into the Vaal River.