Pollution plagues Lagoon Beach

Lagoon Beach has been rated “poor” for the fifth year in a row in the “Know Your Coast” report.

Lagoon Beach has a pollution problem, according to the City’s latest coastal water quality report.

The beach rated “poor” for the fifth year in a row in the “Know Your Coast” report.

The water quality was “excellent” at Table View and “sufficient” at Milnerton Lighthouse and Bloubergstrand’s Big and Small bays.

Melkbosstrand, one of Cape Town’s Blue Flag beaches, was, however, ranked “good” for the second year having been “excellent” in the previous three years.

The latest report covers coastal water quality from December 1, 2020 to November 30, 2021. It reflects the outcome of statistical analysis of 2 400 bacterial sample tests taken from 99 sites on the Atlantic and False Bay coastlines, twice a month in the surf zone and in tidal swimming pools, along a stretch of 307km coastline from Silwerboomstrand 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 gastrointestinal 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”. Enterococci under 100 cfu/100 ml is “excellent”, under 200 is “good”, under 185 is “sufficient” and “poor”. E coli under 250 is “excellent”, and under 500 is “good”, “sufficient” and “poor”.

According to mayoral committee member for spatial planning and environment Eddie Andrews, this is the third “Know Your Coast” report issued by the City.

The report included the sampling results of the previous five years, from 2017 to 2021, which was pivotal in understanding the longer term trends in coastal water quality for Cape Town’s beaches, he said.

Apart from the annual “Know Your Coast” report, the City also publishes bi-weekly data updates on its website.

Mr Andrews said effluent from the City’s sewage-treatment plants had an impact on coastal water quality results in specific areas, but R3.3 billion in upgrades were already under way at the Zandvliet, Potsdam, Mitchell’s Plain, Macassar and Bellville plants and are anticipated to improve coastal water quality on the Atlantic seaboard, specifically in the Milnerton area.

According to the report, the R2.2 billion Potsdam Waste Water Treatment Works upgrade project will progressively provide new technology and additional treatment capacity between now and the estimated completion in August 2025.

The report says stormwater to sewer diversions to address the impact of unlawful land occupations in Dunoon/ Doornbach are being designed for completion in 2023. A Dunoon bulk sewer upgrade was completed in June 2020.

Also, the upgrade of Koeberg Road pump station, including construction of stormwater-to-sewer diversions in Montague Gardens, is to be completed in July 2022.

And the size of this bulk sewer pipeline is being increased at Montague Gardens.

Caroline Marx, from the Milnerton Ratepayers’ Association, said: “We are still waiting for the Urban Run-Off and Inland Water Bodies reports. These provide information on the stormwater culverts leading to our beaches. They alert us to sewage overflows, such as sewage pump stations failing to restart after load shedding events and their alarm systems failing.”

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,” he said.

The water quality was “sufficient” at Bloubergstrand’s Big and Small bays.
R3.3 billion in upgrades are already under way at the Zandvliet, Potsdam, Mitchell’s Plain, Macassar and Bellville sewage-treatment plants and are anticipated to improve coastal water quality on the Atlantic seaboard, specifically in the Milnerton area, says mayoral committee member for spatial planning and environment Eddie Andrews.
According to the report, the R2.2 billion Potsdam Waste Water Treatment Works upgrade project will progressively provide new technology and additional treatment capacity between now and the estimated completion in August 2025.
Melkbosstrand, one of Cape Town’s Blue Flag beaches, was ranked “good” for the second year having been “excellent” in the previous three years.