Organic matter floating off Hout Bay in April 2017. Picture: Karen Watkins.
Hout Bay is one of the most polluted beaches on the Atlantic coastline, according to the City’s latest coastal water quality report.
The beach rated “poor” for the second year in a row in the “Know Your Coast” report.
According to mayoral committee member for spatial planning and environment Eddie Andrews, this is the third Know Your Coast report. He said stormwater and river discharges had the biggest impact on near-shore water quality.
Mr Andrews said the Disa River was polluted and that impacted on the nearshore at Hout Bay.
The latest report covers coastal water quality to September 21, 2023.
The report includes the sampling results from 2018 to 2023, which determined the water quality at recreational beaches, tidal pools, and coastal monitoring points. The key findings come from over 10 000 sample bacterial test sites, twice a month in the surf zone and in tidal swimming pools, along a stretch of 307km coastline from Silwerstroomstrand resort on the Atlantic to Kogel Bay on the east side of False Bay.
The samples are analysed by the City’s scientific services unit and categorised as “excellent”, “good”, “sufficient”, or “poor”, based on a 365-day rolling period.
For most healthy people, water quality that meets acceptable standards, “sufficient” or above, will pose little risk to their health, said the report.
Coastal water quality is assessed by comparing the number of E coli and enterococci bacteria in the water samples to limits set out in the South African Water Quality Guidelines for Coastal Marine Waters. The bacteria serve as indicators of faecal pollution and the potential presence of pathogenic micro-organisms.
The ratings are based on the estimated risk of illness per exposure to swimming for 10 minutes with three head immersions. Less than 2.9% is “excellent”, less than 5% is “good”, less than 8.5% is “sufficient” and more than 8.5% is “poor”.
Apart from the annual Know Your Coast report, the City runs a statistical analysis for each site twice a month.
Caroline Marx, of anti-pollution activist group ReThinkTheStink, said even treated effluent from a sewage plant should contain less than 1000 E coli cfu/100ml, but water at Hout Bay Beach had 2420 E coli cfu/100ml.
Similarly high levels are found in the report at many beaches including Silverstroom (7260), Strand Pavilion jetty (1120), Lagoon Beach, Simon’s Town (1414), and Gordon's Bay (1733), and Ms Marx said they posed possible health risks to users. “How sad in a city famous for its beautiful coastline,” she said.
Llandudno Beach, one of Cape Town’s Blue Flag beaches, was ranked “sufficient” down from “excellent” in 2021 and “good” in 2022.
The report identifies four swimming spots as having chronic coastal water quality problems - Central False Bay, Lagoon Beach in Milnerton, Three Anchor Bay in Sea Point, and Macassar to Gordon’s Bay.
Dr Cleeve Robertson, CEO of the National Sea Rescue Institute, said the City’s data lacked credibility and integrity. Relying solely on E coli measurements gave a limited picture of water quality as sewage could harbour numerous pathogens, he added.
He pointed to discrepancies between the City’s data and the scientific findings of experts such as Professor Leslie Petrik, who leads the Environmental and NanoScience Research Group at UWC, and Dr Jo Barnes, whose primary research focuses on water-related diseases.
Dr Robertson suggested the City was manipulating data to serve its own agenda, which didn't align with the well-being of its citizens.
Marguerite Hofmeyr, managing director of Sentinel Ocean Alliance, said they were deeply concerned about Hout Bay Beach's repeated “poor” ratings.
“This underscores the urgent need for collaborative action to address and rectify the pollution issue. We remain committed to marine conservation and stand ready to work with stakeholders for lasting solutions to enable safe access to the oceans for all," she said.
Mr Andrews said the City needed partnerships with residents. “And for residents to refrain from littering, illegal dumping in our sewers and stormwater mains, and to not dispose of grey water or any other substances in the stormwater mains. Everything that is dumped in our rivers, canals, stormwater mains and streams, from household bin washing, pet waste, household cleaning agents, fats, oils and grease, eventually finds its way into the sea.”
Mayoral committee member for water and sanitation Zahid Badroodien said there was a R8.6 billion capital expenditure on sewage-plant upgrades over three years with R1.8 billion for extensions and upgrades over the next financial year. That would increase to R3 billion for the 2024/25 financial year.
View the report: capetown.gov.za