Imhoff’s Toxic Gift: a lesson for consumers (a call for more phosphate-free products)

Posted on August 25, 2011


While we know some of what went wrong to make the environmental disaster otherwise known as Wildevoelvlei, do we know that one of the key causes of this high level phosphate lake is from what products we flush down our drains daily?

Back in the 50’s and 60’s, Wildevoelvlei was a seasonal wetland. Drier in summer and wetter in winter, this changing scene allowed a huge variety of species to prosper at different times.
Now Wildevoelvlei Lake is there all year round, with the most recent City State of Environment Report calling it ‘the most hypertrophic water body in Cape Town.’

The blue-green algae are the problem here. Although very much a part of the aquatic system, when this algae spreads exponentially it turns poisonous, becoming toxic to the equivalent of a low dose of cyanide.

The blue-green bloom in December 2010.

This has been a recurring phenomenon over a number of summers and we have seen an increasing loss of diversity in the area. It is due to the phosphates and nitrates leaking into Wildevoelvlei from the nearby sewerage system that this blue-green algae flourishes to such a tremendous degree.

Most commercial bathroom body products like soaps, shampoos and body lotions are high in phosphate. Excrement that contains things like steroids, the pill and prescription drugs add to this problem too. Phosphates from these things are difficult to screen out during the sewerage cleansing process and this has resulted in there being too much present at Wildevoelvlei, making nature out of balance in this area.

The accumulation of phosphate-laden sediment at the bottom of the Wildevoelvlei lake is slowly deteriorating the natural eco-system and could ultimately affect the broader wetland system – and the situation is only worsening. However I am certain that very few of the  30 000 people who use this sewerage system are even unaware that they are personally contributing to the environmental tragedy that is Wildevoelvlei today.

Any way you look at it, it seems that reversing the kind of damage that is evident at Imhoff Gift’s lake would be a complex and expensive procedure, so maybe it is worth looking into how we – the consumer – can help to prevent such cases as Wildevoelvlei from happening again.

Patrick Dowling, Regional Head of Environmental Education at WESSA is of the opinion that people should be more aware of the products they use at home and suggests that the government put pressure on cleaning product manufacturers to use more biodegradable ingredients in their products.

Consumers are urged to use phosphate-free products

‘But we must be careful not to demonise phosphate, it is in fact a key component of the planet!,’ adds Patrick. It just appears we are using too much of it, which is throwing nature off balance. Maybe think about that next time you shop.

Examples of local phosphate-free cleaning products:

Michael Melnick
021 555 4828


Cape Care
021 511 2100
40 Neptune Street, Paarden Eiland, 7405

Organic Cleaning
Sea Point Main Road
021 439 4087/86

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