Posted by: Saving Water SA (Cape Town, South Africa) – partnered with Water Rhapsody conservation systems – 27 December 2010
Only a minute share of water in our planet (2.5%) is potable, and most is locked up as ice while only one per cent is available in lakes, rivers and underground water tables for human consumption.
In South Africa our average rainfall is only about half that of the global average – 450mm per year against the world average of 860mm per year. South Africa is a water stressed country yet little emphasis is placed on grey water as a solution. Instead, we look erringly at energy expensive and non-sustainable fixes; such as desalination.
Grey water systems recycle water from baths, basins showers and washing machines to irrigate lawns and gardens. Water from these outlets is re-routed to a small underground chamber from where it is automatically pumped silently to the garden for irrigation.
Providing that laundry washing powder is changed to one that is phosphate free, grey water is perfectly safe for gardens including fynbos gardens. Fabric softeners and JIK should also be avoided.
Generally washing powders are by weight one-third phosphates. These phosphates are sent along with our waste-water to our waste-water treatment plants, and ultimately end up in our rivers and estuaries.
In 1997 there was a catastrophic poisoning of the Wildevoelvlei, one of the Noordhoek Valley Wetlands. A highly toxic blue-green bloom formed on the surface of the lakes as a result of wastewater overflowing from water treatment works. The treated and untreated water had a high concentration of phosphates – a major component of washing powder. SANParks eventually turned the lake anoxic, thereby killing an entire generation of organisms.
Regretfully this situation has once again surfaced and Wildevoelvlei is currently a no-go area due to the toxicity of the blue-green algae. For this reason alone it makes sense to use a phosphate free washing powder.