What is Greywater?

Graywater is household waste water that includes the following:

  • Shower Water
  • Bath Water
  • Lavatory (basin) Water
  • Laundry Water
  • Untreated Spa Water

Typically, two thirds of the water used in a water-aware household results in graywater (excluding water used for the garden and lawns).
Blackwater is household waste water that includes:

  • Toilet Water
  • Laundry Water, if the waste water is from washing diapers, or other materials containing feces

Darkwater is household waste water from the kitchen. It may contain food contaminants, oils and powerful detergents (especially dishwashers).
Although many jurisdictions ban the re-use of kitchen water (darkwater), in some situations this water may be used for garden irrigation IF a grease trap is installed between the kitchen waste outlet and a graywater pumping system.

The above definitions apply generally throughout the world, although exact definitions vary from country to country, and in the US from state to state.