- Of Cape Town's 23 sewage treatment plants, 15 are unable to treat sewage to acceptable standards before releasing it into the environment.
- As a result, at least 382 million liters of untreated or partially treated sewage is discharged into Cape Town's rivers and oceans, of which 216 million liters flow into False Bay each day.
- Water quality along the coast from Strandfontein to Gordon's Bay has long been described as 'poor', with scientific studies showing that pharmaceuticals and chemical compounds released in sewage are accumulating in the marine food chain. There is.
The City of Cape Town is considering ways to stop pumping untreated sewage from the Atlantic coast, but GroundUp reports that the city's largest sewage treatment plant near Strandfontein is unable to properly treat the sewage. , is said to be polluting False Bay.
The Cape Flats Wastewater Treatment Works (WWTW) treats at least 114 million liters of sewage per day, according to the 2022 Green Drop Report released by the Department of Water and Sanitation (DWS).
However, data from the DWS Integrated Regulatory Information System (IRIS), which requires all municipalities to post monthly wastewater test results from their wastewater treatment plants, shows that the Cape Flats Wastewater Treatment Plant has been bringing its wastewater to minimum standards for the past six years. This indicates that it cannot be processed. This wastewater is discharged into the bay at Sonwabe Beach via a channel that runs under Baden-Powell Drive.
Wastewater must comply with minimum standards set by DWS before being released into the environment. These include microbiological compliance (amount of fecal bacteria such as E. coli) and chemical compliance (chemical oxygen demand, presence of orthophosphate, nitrate, nitrite, and ammonia).
Cape Flats WWTW average microbiological compliance in 2023 was 0% and chemical compliance was 43%. The microbiological compliance score for wastewater treatment facilities was 2% in 2022, while compliance in 2021 and 2020 was 0%. The highest microbiological compliance score in the past six years was 20% in 2018. The highest score for chemical compliance during the same period was 43. % in 2023.
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With a capacity of 200 million liters per day, the Cape Flats WWTP is by far the largest sewage treatment plant in Cape Town, but it is not the only sewage treatment plant that is failing. According to IRIS data, 15 of Cape Town's 23 wastewater treatment plants failed to meet microbiological and/or chemical compliance last year.
This does not include the untreated marine outfalls at Green Point, Sea Point and Hout Bay, which discharge more than 32 million liters of sewage into the ocean every day. It appears that his 2024 monthly compliance results for Cape Town's sewage treatment business have not yet been loaded into IRIS.
Read in conjunction with the latest Green Drop report, therefore, over 382 million liters of partially treated or untreated sewage was discharged into rivers, estuaries and oceans in and around Cape Town every day during 2023 .
Of this, 216 million liters enters False Bay every day and is released either directly into the sea or via rivers such as the Erste. The rest flowed into the Atlantic Ocean on the west coast.
coastal water quality
The coastal water quality report issued by the city and available now shows the results of weekly samples taken at 14 popular recreation areas in False Bay between Oct. 3 and Jan. 30. . These were analyzed by an independent laboratory as part of a 12-month research program. Results show that high levels of enterococci (bacteria indicative of sewage contamination) have been detected multiple times in different locations in False Bay.
Separately, the city's scientific services conduct water quality tests every two weeks at 99 coastal sites (45 on the Atlantic Coast and 54 in False Bay), but in March of last year, at the time, Water and Sanitation Mr. Siseko Mbandezi, who was acting Meiko Commissioner in charge, said: City labs have not been able to test for enterococci since at least November 2022 “due to delays and quality issues with received chemicals and supplies.”
This issue appears to have begun to be resolved in November 2023 when the city began presenting enterococcus results again, but enterococcus data for many facilities is still not available. However, scientific institutions continue to test for E. coli as an indicator of fecal contamination, even though World Health Organization (WHO) guidelines cast doubt on E. coli being a meaningful indicator of coastal water quality.
This is the exit from the Cape Flats Wastewater Treatment Plant to False Bay.
A year-long gap in enterococcal analysis by scientific institutions, an independent research program in which samples at 30 recreational facilities are tested in independent laboratories, and a monthly Blue Flag program at 11 selected beaches. As a result of the combination of tests, the display of water quality results on the city's website has changed multiple times over the past three months.
Previously, the city presented a 365-day rolling average of water quality for all 99 testing facilities dating back to 2018, grading facilities as “poor,” “satisfactory,” “good” or “excellent.” The last such graded result set, downloaded by GroundUp in November 2023, showed that all 27 testing facilities in False Bay, located between Mnandi Beach and Gordon's Bay, had chronically poor results. ” Water quality is indicated. Strandfontein Beach has been rated 'good' since 2019, except for being rated 'poor' in 2022.
Studies have shown that the mainstream flow in False Bay is clockwise, so wastewater released from the Cape Flats WWTP flows along the coast from Strandfontein to Mnandi and then into Gordon's Bay. may be expected to move eastward. In line with this, the Cape Flats WWTW is mentioned as a possible source of pollution in the city's 2020 Know Your Coast report.
eternal chemicals
In addition to fecal bacteria and other disease-causing pathogens, sewage also contains pharmaceutical compounds such as antibiotics, painkillers, antiretrovirals, household disinfectants, and perfluoroalkyl substances and polysaccharides that break down very slowly. Contains a group of synthetic compounds known as fluoroalkyl substances (PFAS). If so. Currently, pharmaceuticals, disinfectants, and PFAS are not removed from wastewater by even the most well-functioning treatment plants.
A study by University of the Western Cape senior professors Leslie Petrick and Cecilia Y. Ojemaye found that many of these compounds accumulate in the flesh of fish caught in Kalk Bay port. Their study, published in 2019, stated that “these chemicals pose a high health risk to pelagic fish and aquatic organisms, as well as to humans who consume them.”
Further research by Petrik and Ojemaye, published in 2021, found that these persistent chemical compounds are present in False Bay seawater and sediments, accumulate in seaweed through the food chain, and are found in limpets, mussels, sea urchins, snails, And starfish. The most common compounds are the widely prescribed anti-inflammatory drug diclofenac and the antibiotic sulfamethoxazole, which contribute to antibiotic resistance in associated fecal bacteria released into sewage wastewater. There are growing concerns that this may occur.
City response
Zahid Badrudien, Mayco's member for water and sanitation, said the city is “increasing investment” in wastewater treatment projects “to address a number of challenges around infrastructure, capacity challenges and treatment processes.” Stated.
Mr Badrudeen said it was estimated that R1.8 billion would be spent on expanding and upgrading WWTW in the 2023/2024 financial year, increasing to R3 billion in the 2024/25 financial year.
He said challenges related to treatment processes were being addressed to improve wastewater quality, particularly in the Cape Flats WWTW. As for other wastewater treatment facilities discharging wastewater into False Bay, the Makassar WWTP will undergo a “major overhaul” and upgrade from its current capacity of 34 million liters per day to 70 million liters per day. It is planned that But he said it was within Eskom's electricity supply area and was affected by Eskom's load shedding. He said Eskom had rejected a request to be exempted from load shedding.
This is the Cape Flats sewage treatment facility.
Gordon's Bay WWTW is performing relatively well, but it is within Eskom's supply area and “load shedding has caused some issues,” he said.
Similarly, requests to be excluded from load shedding were also rejected by Eskom. He said the Belleville wastewater treatment plant, whose wastewater flows into False Bay via the Eerste River, was in the final stages of renovation and treatment process upgrades.
However, there was no mention of plans for the troubled Mitchells Plain wastewater treatment plant, which is expected to achieve only 36% chemical compliance in 2023 and generate at least 26 million sewage waste per day. liters of partially treated sewage is discharged into False Bay.
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Similarly, there is no mention of Scottsden WWTW. In the end, microbiological compliance was achieved at 39% and chemical compliance at 32%, and he discharged 8 million liters of partially treated sewage per day into the Botelary River. The River Botelary flows into False Bay via the River Quill and then the River Elste.
Similarly, Simon's Town WWTW will achieve only 42% chemical compliance in 2023, despite operating at just 24% of its 5 million liters per day capacity. , 1.2 million liters of partially treated wastewater are discharged directly into the bay every day.
But other wastewater treatment facilities are also undergoing upgrades and renovations. These are Athlone, Potsdam, Vesfleur, and Vildevolvrei in Comezie. All of these discharge wastewater either directly or indirectly into the Atlantic Ocean on the west coast.
