Raw Water and Treated Water:
Raw Water
Raw water is that is extracted from the source and that has not undergone any treatment process. For drinking water treatment, the cleanest possible source should be chosen, which will result in lower treatment costs. In addition, although it is extremely difficult to find sources that offer drinking water quality, "potable" raw water qualities will be sought; this means that its physical, chemical and biological characteristics can be managed with treatments, known as conventional, or those normally used in water treatment plants, i.e., coagulation, flocculation, sedimentation, filtration (see the corresponding Wiki).
Treated water
Treated water is the one that results from applying the processes used in the PTAP, which, as explained in the corresponding Wikis, can be physical and / or chemical.
Treated water levels
Although drinking water quality standards are similar worldwide, there are some more stringent regulations than others. In general, the demands tend to be higher in the more developed countries. According to the levels of demand, the regulations were classified into four levels (categorized as 1,2,3 and 4), which are presented in the following table:
The combination of certain raw water quality with the different levels of drinking water quality will give us different treatment trains, as described in the corresponding Wiki.
Bibliography
Teoría y práctica de la purificación del agua. 2000. ACODAL. | https://es.scribd.com/document/450177856/arboleda-valencia-teoria-y-practica-purificacion-agua-pdf
Potabilización del agua: Principios de diseño, control de procesos y laboratorio. 2009. Lozano-Rivas, WA, & Lozano Bravo, G. as, WA, & Lozano Bravo, G.. | https://es.scribd.com/book/323226019/Potabilizacion-del-agua-Principios-de-diseno-control-de-procesos-y-laboratorio
Referencies
¿Cuál es la diferencia entre el agua cruda y el agua potable? | http://agenciasanluis.com/notas/2018/02/06/cual-es-la-diferencia-entre-el-agua-cruda-y-el-agua-potable/