There are 27 locations in the eThekwini Municipality spread out across the north, south and western parts of the City, where sewage gets treated before it is discharged into a river or the ocean, according to water and sanitation map data.
These facilities are called Wastewater Treatment Works (WWTW) and are responsible for treating effluent collected from each respective region.
All 27 of these WWTW’s are located near a water source, which in this case, are rivers.
The waste that is treated at these sites is collected via eThekwini’s 9,149 km long sewer network, according to the 2022 Green Drop report for KwaZulu-Natal.
These rivers flow east, where they meet with the Indian ocean here in eThekwini.
According to the Municipality website, it has been discharging sewage and selected industrial wastes through two deep-sea submarine outfalls since about 1970.
These WWTW’s have been a talking point for many around the problem regarding the levels of E. coli found in Durban waters, be it a fresh or salt water source.
The functionality of the WWTW’s have also been a sore point, as the facilities suffered heavy damage during the 2022 floods which affected their capacity for processing raw sewage.
According to the The Department of Water and Sanitation (DWS) rating system, if a WWTW is compliant less than 50% of the time, it is considered to be in “bad” state.
If it is compliant with effluent treating standards less than 50% to 70% of the time, then it is considered to be in a “poor” state.
But the floods alone cannot be held liable for the poor performance of the WWTW, as they were in a poor functional state prior to the destruction in 2022, a wetland ecologist, who asked to remain anonymous, told IOL.
The 2022 KZN Green Drop report, which measures the results from 2021, shows that eThekwini’s system achieved lower results than the previous years.
This report is compiled by the Department of Water and Sanitation.
The Green Drop (GD) scores are based on a number of factors, including process control, maintenance and management skills, and wastewater quality monitoring, to name a few.
For the 2021 period, eThekwini scored 76%, while the City was in the 90 percentile during 2013 and 2011.
“None of the WWTWs achieved >90% effluent quality compliance, which carries the highest weight in audit scoring,” the 2022 report stated.
“The most prominent risks were observed on treatment level, and pointed to works that exceeded their design capacity, dysfunctional processes, and equipment (especially disinfection), and effluent and sludge non-compliance,” the 2023 report said.
Following the destruction to state infrastructure after the April 2022 floods, two major WWTW in eThekwini, the central and southern branch, had 0% compliance for microbiological treatment, Groundup reported.
Microbiological treatment is used to measure the E. coli and other faecal bacteria content in water.
IOL