City sewage disposal worry

Feminisation, caused by contraceptive residues and hormones in water bodies, is the greatest threat to marine life as it means extinction for affected species.

Cape Town pumps 55 million litres of sewage into the surrounding ocean and inland rivers from three outfalls daily, but only one has a permit to do so.

The national Department of Agriculture Forestry and Fisheries issued the permit to the City of Cape Town on May 7 for the Hout Bay Waste Water Treatment Works, but there are no permits for the Green Point and Camps Bay outfalls because, according to Department of Environmental Affairs(DEA)spokeswoman, Zolile Nqayi, the department is still considering the applications for them.

“The City is required to undertake a marine impact assessment every year from the date of issue to ensure that effluent does not compromise human health and the marine ecosystem,” Ms Nqayi said.

Professor Leslie Petrik, from the University of the Western Cape, is a scientist who is deeply concerned with her team’s findings of pharmaceutical chemical compounds in fish (“Marine life chemical threat,” False Bay Echo, March 1).

She warns that the greatest threat to marine life is feminisation, as it means extinction for affected species.

“We have to remove contraceptive residues and hormones from the effluent to prevent this happening,” she told the False Bay Echo.

Antibiotics, pain killers, antiretrovirals, disinfectants, and industrial chemicals are also part of the harmful soup hurting our marine life.

Among the species tested for 15 different chemical compounds were snoek, bonita, hottentot (Cape bream) and panga.

Professor Petrik said sewage plants must be upgraded to counter the chemical threat.

It was not good enough for the City to dismiss the problem by saying it was a global issue as people’s health was at stake, she said.

Professor Petrik said with frequent sewage spills in Zandvlei, the presence of E Coli was an indication that other pathogens such as Staph were present and they could make people sick.

Synthetic chemicals posed a far greater threat to marine life than plastics “as they affect living creatures at cellular and sub-cellular levels”, she said.

Xanthea Limberg, mayoral committee member for water and waste, claimed sewage outfalls were operating within licence conditions and there were no plans to introduce additional treatment steps.

But when the Echo asked how that was possible if the Camps Bay and Green Point outfalls didn’t have permits, she said she had been referring to licensing for effluent quantities.

The marine outfalls had always been licensed throughout their more than 30 years in operation, she said.

“However, with the fairly recent promulgation of the National Environmental Management: Integrated Coastal Management Act, came a new requirement that a coastal waters discharge permit (CWDP), a newly-created permit, will be issued by the now Department of Environmental Affairs. While this CWDP application process is under way, the outfalls should still be considered licensed according to the older conditions,” she claimed.

The City was waiting to hear from the DEA whether it should change its treatment technologies in order to get permits for the other two outfalls

Claims that fish were being contaminated by sewage from the outfalls were not supported by evidence, Ms Limberg said.

She quoted a City-commissioned study in 2015 which said sewage outfalls’ contribution was not discernible from background pollution.

Minimal cleansing is done at the three outfalls, but the process is more stringent at the City’s 20 tertiary sewage plants, where the effluent is processed before it reaches the outfalls. However, Ms Limberg noted that the sewage-treatment process at tertiary plants was only partially effective at breaking down chemicals.

“This phenomenon is by no means caused by Cape Town or wastewater generated by any one City, but should be seen as inevitable when taking into account society’s relationship with pharmaceuticals and cleaning products over the course of the modern history of the world,” she said.

She said a recently published study states snoek fillets tested contained 0.0000018 g of Diclofenac.

“One would have to eat 41.7 kg of snoek fillets in a single sitting in order to ingest the equivalent of 1 Diclofenac tablet.”

She claimed other studies had found the concentrations of chemical pollutants (pharmaceuticals, pesticides, endocrine disruptors etc) in our seas were at lower levels than other coastal cities.

The Echo asked Ms Limberg for copies of these studies, but she did not send them by the time this edition went to print.

Ms Limberg said the City was preparing a full report on coastal water quality which should be presented to portfolio committees in August, after which the results could be made public.

Pedro Garcia, spokesman for the South African United Fishing Front, said nobody in the fishing industry wanted to send anyone to their grave by eating contaminated fish so he welcomed studies, but he questioned their unintended consequences and said they could potentially rob fishermen of their livelihood.

“The Kalk Bay fishermen have fished for generations; their whole lives are built on fishing,” he said.

He questioned why the study pointed only to small scale fishers and why the higher value species such as the West Coast rock lobsters and octopus were not being examined.

“The bigger worry for future fishing is the damage done by West Coast rock lobster and octopus fishing traps on the natural habitat of the bay and how that has chased so many of the local fish out into deeper waters,” he said.