Several million litres of almost raw sewage are flushed into Cape Town’s oceans every day through marine outfalls in Green Point, Camps Bay and Hout Bay. As a result, our sea and the inhabitants are exposed to large quantities of pharmaceutical drugs and chemical cleaning agents that have made their way down our drains.
These are persistent organic compounds, which means they do not break down. Among these non-biodegradable drugs and cleaning agents are: antibiotics, analgesics, blood lipid regulators, natural and synthetic hormones, beta-blockers, antidiabetic and blood pressure drugs, and chemicals from soaps, detergents, disinfectants, perfumes, dental care products, skincare products, and hair products.
There are possibly hundreds more in the ocean in addition to these, which are just the known pollutants scientists have tested for so far.
A cocktail of 15 pharmacological compounds was found in mussels, sea urchins, starfish, limpets, sea snails, and seaweed collected from rock pools in Granger Bay by scientists.
Senior professor in chemistry at the University of the Western Cape Leslie Petrik told GroundUp the accumulation of these compounds in limpets, for example, impairs their ability to cling to rocks, which results in them getting washed away and dying.
Mussels have been found to soak up these compounds particularly easily and these ocean delicacies are a popular food source among locals.
This problem is not unique to the Cape; many other coastal cities around the world deal with the same dangerous compound deposits due to sewage outfalls.
Mayoral committee member for water and waste services Xanthea Limberg told GroundUp that according to the World Health Organisation there is no acute health risk posed by accumulated traces of common chemical compounds in our environment. However, Limberg said the City is “keeping abreast of developments in this field”.
“No full-scale municipal wastewater treatment plant in South Africa or anywhere else in the world that we are aware of is currently equipped to remove CECs from the water they treat.”
Research into effective full-scale treatment plans for the removal of these harmful compounds around the world is still ongoing and no official process has been decided on as of yet.
The idea to pump sewage out to sea was approved when volumes of these chemicals and drugs in the sewerage systems were relatively smaller. In addition, the marine outfalls were built during a time when the sheer variety and volume of manufactured chemicals and pharmacological compounds in sewage was far lower.
There can be no doubt that the City needs to begin investigating new sewage treatment technologies, but Capetonians should also be taking responsibility for what they flush down toilets and drains.
Residents need to be more aware of the products they use and what they do with them after use, as well as whether or not they are harmful to the environment.