1.2.1 Types of liquid waste
The types and characteristics of liquid wastes are discussed in Study Session 4, but a useful general classification of domestic liquid waste is as follows:
- Blackwater – is wastewater that contains or consists of urine and faeces. It contains pathogens (disease-causing agents).
- Greywater, or sullage, is wastewater from human washing and bathing, kitchen sinks, clothes washing, etc. It does not contain excreta.
- Stormwater (or surface run-off or rainwater run-off) is wastewater that flows on the surface of the land to join streams. Note that this is considered as wastewater because it contains many different contaminants.
- Sewage is a combination of wastewater coming from any of the above sources and flows in underground sewers or open ditches.
- Excreta is a combination of urine and faeces.