Greywater
At a domestic scale many householders currently re-use their greywater for garden watering.

What is Greywater?
Water that is discharged from household appliances and water using fixtures such as:

  • showers/baths
  • washing machines & washing sinks
  • kitchen sinks & dishwashers (If used for disposal of fats and proteins, then not recommended)

It excludes water discharged from toilets, bidets and urinals (black water) .

What are the risks in using Greywater?
Greywater contains large numbers of bacteria that may include disease causing organisms. It also contains a number of pollutants including organic matter, nutrients, salts and detergents. Long term watering with greywater can effect sensitive garden plants and soil. Not good for fynbos, but great for lawns.

Am I allowed to reuse Greywater?
You may divert untreated greywater for immediate re-use, as long as there are no adverse impacts on public health or the environment, caused by greywater run-off to stormwater.

  • Use a licensed plumber to install the diversion system
  • Water diversion systems are best restricted to low risk sources such as bath, shower and laundry rinse water
  • Kitchen water should not be used as it is heavily contaminated with fats, greases and solids
  • Laundry wash water is also high in detergent concentrations
  • Be aware of biodegradable labeled products
  • Only divert in hot dry conditions, in quantities that can be taken up by plants & soil
  • Ensure there is no cross connection of greywater with the drinking water supply
  • It is not good to store greywater for later use in a tank (24 hr maximum storage)
  • Do not discharge greywater near agi pipes as the greywater will flow into the stormwater system
  • Place signage around the areas you discharge greywater – so people are aware.