DURBAN - ETHEKWINI Municipality’s wastewater discharge into the sea will come under the spotlight during a public meeting aimed at sharing findings of a study into the impact of the practice on bathers and marine life.
The effect of wastewater discharge on the marine environment in Durban has been monitored closely by scientists over the past 40 years, resulting in the “Sea Disposal of Sewage: Environmental Surveys in the Durban Outfalls Region”, the Council for Scientific and Industrial Research (CSIR) has said.
The monitoring programme generated a wealth of information that contributed to the understanding of how wastewater discharge affected the sea environment off Durban, CSIR said in a statement.
“Like coastal cities in most parts of the world, a significant amount of wastewater, which is generated daily in households and industries in parts of Durban, is discharged to the sea through deep water outfalls,” the CSIR said.
“Wastewater contains a variety of chemicals (such as metals), bacteria and viruses that can potentially affect the ecological health of the sea and pose a threat to the health of humans when swimming or when extracting resources such as fish from the sea.
“The Durban outfalls (specially designed pipes for disposing of wastewater into a waterbody) monitoring programme is one of the longest continuous wastewater discharge monitoring programmes in South Africa and possibly the world (over 40 years), and in the SA context, it is by far the most comprehensive outfall monitoring programme.
“The programme uses various indicators of environmental health to draw conclusions on the impact of wastewater discharge. Indicators include the presence of bacteria found in human faeces in the sea, as well as concentrations of contaminants such as metals, oils and pesticides in the sea and on the seabed. The health of benthic macrofaunal communities on the seabed is also assessed,” the CSIR stated.
In a public notice, eThekwini said the primary aim of the public engagement later this week was to “enlighten the public on the outcome of the studies done, which is the impacts of the sea outfalls on the receiving environment during this time”.
Prof Anthony Turton, an environmentalist and water analyst based at the Free State University, said Durban had appeared to have been on a trajectory to lead to an end to ocean discharge of wastewater.
Turton cited the R74 million sewage-to-clean-water recycling project planned to treat 47.5 million litres of domestic and industrial wastewater for reuse by industries.
“This new report suggests a backward step rather than building on the momentum that was achieved in the early 2000s,” he said.
Professor Mike Muller of the Wits School of Governance and chairperson of the Water Institute of SA’s Technical Committee, said treating wastewater to a higher quality for reuse was a better option than simply dumping it into the sea.
Muller added that treating wastewater for reuse was cheaper since the treatment cost would be covered by the user, who will also pay lower tariffs than those paid for potable water.
THE MERCURY