After a nine-year hiatus, the long-awaited Green Drop report paints a bleak image: half of wastewater treatment works in South Africa fail to deal with sewage correctly and in lots of circumstances fail to deal with it in any respect.
Anthony Turton from the Centre for Environmental Management on the University of the Free State says this represents “a tsunami of human waste inundating our rivers and dams, without respite, for more than a decade”.
The quantity of crucial treatment works listed within the final report in 2013, was 248. The newest Green Drop report, launched on 30 March 2022, reveals wastewater compliance has plummeted within the intervening years. Of 850 municipal wastewater treatment works, 334 (39%) are in a crucial state, acquiring a rating of 30% or much less.
“This decline is at both the treatment and sewer collection levels,” states the report. It is not only that wastewater treatment works are failing to correctly deal with sewage earlier than releasing it again into the atmosphere, a lot of it’s spilling into the atmosphere earlier than even attending to the treatment works.
The common Green Drop rating throughout all provinces was 50%, indicating that about half our uncooked sewage and industrial waste shouldn’t be being handled to requirements which are already insufficient, based on scientists within the fields of chemistry and epidemiology. The common rating in 2013 was 61%.
The Green Drop rating drop
But evaluation of the Department of Water and Sanitation’s (DWS) personal knowledge exhibits that even some of the few wastewater treatment works which acquired scores of 90% or extra, are polluting the atmosphere.
Key to understanding that is the acronym NMR, which stands for No Monitoring Required. It shouldn’t be mirrored within the nationwide Green Drop report, however is discovered within the particular person provincial experiences.
Green Drop scores for wastewater treatment works and the sewerage infrastructure servicing them are obtained utilizing an equation through which weightings are given to 5 key efficiency areas: capability administration; environmental administration; monetary administration; technical administration; and effluent and sludge compliance, which, at 30%, has the best weighting.
The report notes: “The effluent quality must comply to 90% (in total) with the authorised limits for the respective categories.”
There are three effluent high quality indicators: microbiological compliance, indicating the focus of faecal micro organism corresponding to E.coli and enterococcus within the water; chemical compliance, indicating the focus of chemical compounds corresponding to nitrates and phosphates which negatively impression ecosystems; and bodily compliance, indicating turbidity, electrical conductivity, and oxygen demand. The minimal compliance ranges are set out within the wastewater treatment works’ authorisation issued by the DWS.
No Monitoring Required means a wastewater treatment works is exempt, based on its authorisation, from having to adjust to all or some of these effluent high quality indicators.
Five of the 22 Green Drop award winners fall into this class. All of these are within the Western Cape, which obtained 12 Green Drop awards.
All graphics produced for this text by Yuxi Wang of the Center for Collaborative Investigative Journalism.
The Green Point and Hout Bay wastewater treatment works within the City of Cape Town are each Green Drop award winners. They are additionally marine outfalls. The solely treatment the sewage receives earlier than being pumped into the ocean is maceration by way of a 3mm sieve to take away solids and grit. The Green Point waste comprises pharmaceutical and light-weight industrial wastewater.
Neither of these amenities are required to observe or scale back the faecal micro organism within the wastewater earlier than releasing thousands and thousands of litres of sewage into the ocean per day.
Following analysis carried out by Edda Weimann in 2013 that discovered Clifton seaside contaminated with faecal micro organism, media experiences and a public outcry over the marine outfalls led to the City commissioning its personal report.
Conducted by the Council for Scientific and Industrial Research (CSIR) in 2017, it discovered “no immediate ecological disaster” was imminent consequently of effluent discharge from Cape Town’s marine outfalls.
But the report acknowledged that there was “indirect evidence from faecal indicator bacteria counts in seawater samples collected at many sites along the Cape Town shoreline over an extended period that effluent is possibly, even if infrequently, reaching the shoreline”.
The CSIR report famous that though sewage outfalls are widespread in coastal cities world wide, “the world cannot use the marine environment as a waste receptacle in perpetuity and opportunities for improved and economically and environmentally feasible wastewater treatment, and the feasibility of using alternate strategies for disposing of wastewater to the marine environment should be investigated by the City of Cape Town (and other municipalities)”.
The City has acknowledged it has no plans to divert wastewater disposed through the marine outfalls to wastewater treatment works.
Research in 2017 led by Professor Leslie Petrik of the University of the Western Cape Chemistry Department to find out whether or not sewage air pollution was affecting seawater and marine organisms discovered E. coli counts close to the outfalls that have been hundreds of instances above the overall restrict for handled wastewater effluent.
Besides micro organism corresponding to E. coli, and the nitrates and phosphates which are speculated to be eliminated throughout wastewater treatment, Petrik and her colleagues mentioned that the sewage comprises chemical compounds of rising concern which present wastewater treatment strategies, when utilized, don’t take away.
There are hundreds of these artificial chemical compounds utilized in prescription drugs, private hygiene merchandise, pesticides and industrial purposes. These are secure compounds which don’t break down within the atmosphere, however accumulate.
Petrik and her colleagues examined for 15 of them within the space surrounding the Green Point marine outfall. They included diclofenac (an anti-inflammatory drug generally often called Voltaren), sulfamethoxazole (an antibiotic used for a range of infections), phenytoin (a drugs used to stop seizures), carbamazepine (a drugs for epilepsy and bi-polar dysfunction), lamivudine (used to deal with HIV and Hepatitis B), and paracetamol. These have been all discovered to be current in moist sea sand, and accumulating in marine organisms corresponding to seaweed, sea urchins, starfish, and limpets.
Further research discovered some of these chemical compounds accumulating in fish in False Bay, on the Indian Ocean facet of the town. False Bay receives effluent both straight or not directly from seven wastewater treatment crops, none of which acquired Green Drop certification awards.
The largest plant, the Cape Flats wastewater treatment plant which releases effluent into False Bay, scored 0% for microbiological compliance in 2020 and 2021 from the DWS. For chemical compliance it scored a mean of 37%. Yet, inexplicably, it achieved a Green Drop rating of 85%.
Further clouding the image is the Green Drop report’s introduction of the contender awards. These are given to wastewater treatment works which fulfil all standards however are disqualified from receiving a 90% rating (the minimal for a certification award) as a result of they fail to deal with the effluent to minimal requirements.
Contender standing was awarded to 30 wastewater treatment works within the nation, giving the impression their environmental impression is suitable. However, eight of them failed dismally when it got here to effluent high quality, cumulatively releasing billions of litres of partially handled sewage into their catchments.
Releasing roughly million litres of effluent into the Diep River each day, Potsdam wastewater treatment works was given an 89% rating within the Green Drop report, but it solely met minimal requirements for effluent high quality simply 9% of the time in the course of the yr below overview.
One of solely six giant estuaries on South Africa’s west coast, the Diep River estuary in Milnerton, Cape Town skilled a fish die-off in March.
Estuaries corresponding to these are critically essential as fish nurseries, says marine biologist and founder and director of Anchor Environmental Consultants Dr Barry Clark.
They are breeding grounds for a big quantity of species which are essential for inshore fisheries, which are a supply of livelihood for small scale business and subsistence fishers, in addition to leisure fishers who contribute to native economies.
The Green Point marine outfall pipe, located at Mouille Point, by way of which greater than 20 million litres of uncooked sewage is pumped 1.7km out to sea every single day. Image: Steve Kretzmann
“On the west coast there are only five or six reasonably large estuaries, and the Diep River is one of them,” mentioned Clark, with their shortage making them “disproportionately important to fisheries”.
With Potsdam wastewater treatment works releasing large volumes of wastewater into the Diep River estuary, it’s in an “extremely poor state of health at the moment”.
He mentioned the standard of wastewater flowing into the estuary has “deteriorated severely” over the past decade.
“Diep River estuary is hugely important and it’s a tragedy it’s effectively lost to society,” mentioned Clark.
The City of Cape Town is making efforts to improve Potsdam wastewater treatment works and rehabilitate the Diep River estuary, however is falling brief of assembly a directive meted out by the provincial Environmental Management Inspectorate in 2020.
Another of Cape Town’s excessive scoring contender wastewater treatment works is Athlone, which releases effluent into the Black River, a significant river operating by way of the central metropolis space. Athlone wastewater treatment works scored simply 15% on common for microbiological compliance throughout 2020 and 2021 – the interval of the newest Green Drop audit. Its chemical compliance ranges have been at 54% for the interval.
Flowing by way of an industrial space, additionally it is polluted by excessive ranges of heavy metals, as University of the Cape Town Masters scholar Lucy Gilbert present in 2015.
Yet the Black River stays a supply of meals and earnings for some Capetonians.
Abibat Lamidi buys catfish caught within the Black River to make a conventional pepper stew for her clients. She says the fish from the river odor like petrol, however the sturdy spices the dish requires disguise this. Image: Peter Luhanga
Abibat Lamidi runs a restaurant within the Maitland semi-industrial space close to the Black River. Lamidi says she buys catfish caught within the Black River by casual fishers, paying between R30 to R50 a fish. She makes use of it as a base for a conventional pepper soup sought by her Nigerian clients.
But she says the style of the Black River catfish could be very totally different from catfish in Nigeria. “This catfish smells like petrol.” But she disguises the style with the sturdy spices that make up the dish.
Given research revealing bioaccumulation of chemical compounds up the meals chain within the diluted seawaters alongside Cape Town’s coast, the long run impact of consuming fish from the Black River, the place pollution are extra concentrated, is of concern.
Polluted effluent flows from the Cape Flats Wastewater Treatment Works into False Bay at Strandfontein. According to Department of Water and Sanitation knowledge, the Cape Flats treatment works scored 0% for microbiological compliance in 2020 and 2021. For chemical compliance, it complied with necessities simply 37% of the time on common over the 2 years. Image: Steve Kretzmann
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