When assessing some of the E. coli test results published by water testing company Talbot and the eThekwini Municipality taken from beaches in the city, there have been numerous comments regarding the sudden spikes and drops in bacteria levels, which drew some scrutiny to the testing integrity.
But further analysis and conversations with experts have shed light on the possibility of sudden drops and spikes in E. coli levels along the Durban beachfront and other beaches in the city.
This primarily revolves around the wind conditions, currents underwater, and level of flow from stormwater drains, according to Doctor Justin Pringle from the University of KwaZulu-Natal’s Engineering Department.
The 35-year-old led the charge and brought a platform to the public that offers them a real-time monitor of E. coli levels on the coast to help the public make more informed decisions.
The platform, Woz'Olwandle, uses a wide range of data points, like real-time and forecast winds, rain, and river/stormwater drain flows, to predict whether or not it is safe for bathers.
It measures levels at six Durban beaches, namely the Country Club, Pirates, North, South, uShaka, and Point beaches.
To the public eye, the system is simple to read as it relays the E. coli conditions in three emojis: sad, neutral, or happy.
“We divide the coastline into cells and solve basic conservation equations to estimate the E. coli concentration within each cell.
“Think of it as a weather forecaster but for E. coli levels,” Pringle told IOL.
The platform idea was first thought of around 20 years ago by another UKZN alumni, Professor Derek Stretch, and his student Dave Mardon.
Stretch and Mardon came up with the idea for the intuitive model after encountering a similar problem in Durban decades ago.
After the floods in 2022, which destroyed many critical sewage processing plants in Durban, the city was unable to treat its effluent and thus discarded it into rivers nearby these facilities, which eventually found their way to the ocean.
In November last year, two wastewater treatment works facilities collectively released around 461 million litres of effluent directly into the ocean per day, a Groundup report found.
After flowing downstream, this bacteria can be distributed in a number of directions, depending on the weather and other conditions.
This is where the Woz'Olwandle platform comes in.
“In December last year, teaming up with Professor Stretch and Mardon, I put the model together, which basically feeds the information to the website and updates it accordingly every time new information is received.
“Currently, we use Talbot’s information who is testing together with the city. There are six data points to test for E. coli levels at the beach.
“The model provides an accurate reading as it offers real-time results based on test results and the other data it assesses, like the wind. I think this can help people make better decisions about if they are going to swim or not.
“For instance, if there is a strong south-westerly wind, then whatever flows out of the Umgeni river is likely to be pushed up north towards Umhlanga. If there is a north-easterly wind, then that will be pushed south towards the Durban beachfront.
“Sometimes, if the flow out of the Umgeni is strong, then it will be pushed off-shore.
“The model is able to predict all of this and relay that information in real time,” Pringle explained.
In March, Pringle pitched the idea to some representatives from the municipality.
He said solving the E. coli problem required better working relationships, as it involved more than state intervention but also efforts from the scientific and private communities in terms of data collection and dissemination of that information.
IOL