Different particular wastewater streams are forming the domestic wastewater (see figure 1). The wastewater originating from toilets is called black water and can be further divided into yellow water (urine with or without flush water) and brown water (toilet wastewater without urine). Additionally, grey water is that part of domestic wastewater which originates from kitchen, shower, wash basin and laundry (for more details see Lesson A1).

Figure 1: Sources of domestic wastewater (Samwel 2005)