The sandy strips of Durban are ready to welcome holiday makers this festive season.
The eThekwini municipality has declared the majority of beaches safe and open for swimming, giving encouragement to those ready to flock south for the summer.
The safety of the beaches relates to the quality of the water based on the E. coli concentration at points along the shore.
Over 90% of Durban beaches open
This is measured by the colony forming units (CFU) present per 100 millilitre water sample. Under 150 CFU is considered good, while anything over 500 is deemed poor, leading to the beach’s closure.
The space between is considered acceptable as it is below the amount that poses a threat to the swimmer’s health.
Measurements are taken weekly by the municipality who post regular updates on their website listing the Ecoli content of each of their 23 beaches.
As of the most recent readings, 21 beaches were declared safe for swimming. The two singled out are Ansteys and Reunion beaches who registered over 3000 CFU each.
The beaches with the best water quality currently are Point, Umdloti and Umgababa which all have 20 or less CFU per 100mls. Five others were also under 100.
However, of the 12 beaches rated as ‘acceptable’, three are pushing the upper limits of the 500 CFU threshold, namely, Thekwini, Umhlanga main and Westbrook beaches.
CFU readings always in flux
The main source of pollution is cited as the Umgeni river and the wastewater treatment works upstream that is believed to operating at a substandard level.
Durban University of Technology’s Institute of Water and Wastewater Technology take their own samples weekly to compliment the work of the municipality.
The institute’s director Professor Faizal Bux told The Citizen that E. coli levels constantly fluctuate as they are subject to a host of conditions.
Professor Bux explained that E. coli does not survive for long periods of time in ocean water, lasting only about a day or two.
“It changes all the time and all depends on the source of pollution. The current, tide, wind direction and rainfall can all contribute to weekly changes in Ecoli levels,” said the Professor.
Bux relayed that there were no significant discrepancies between their readings and that of the municipality, who were adamant the city’s beaches are ready.
“We don’t have any challenges with the beaches. 21 beaches are open for swimming in the city,” said eThekwini Mayor Cyril Xaba’s office.
Public to be water conscious
While the beaches may have been declared safe, WaterCAN’s Dr Ferrial Adam said more needed to be done to keep water ecosystems clean.
“Sewage is spewing into our rivers and streams at alarming levels. If it was less, the environment could naturally clean the system but the concentration [of pollution] makes it very hard to clean,” Dr Adam explained to The Citizen.
Dr Adam stressed that E.coli was widely found in most natural water sources where there is human activity and that while it broke down over time, it would be replenished by the original sources.
Professor Bux identified the wastewater treatment works as contributor to the pollution and Dr Adam confirmed that rivers can move E.coli long distances downstream.
“In the ocean, it is likely from freshwater sources, rivers and streams. In cities, it’s storm water drains, particularly after heavy rain,” Dr Adam explained.
“What matters is not its presence but its concentration. Too high and it can cause illness,” she concluded.
