Requirements for raw water quality

The quality of drinking water depends considerably on the quality of the raw water from the water source. Its quality is influenced by meteorological and hydrological factors, and it varies according to the seasons, etc. 

In the search for suitable sources of drinking water for public supply, long-term observations of the water source capacity and water quality are carried out. Water sources with permanent contamination from harmful substances are ruled out. It is also necessary to take into consideration the hydrological balance of the water source, as well as many other factors. 

Because of the seriousness of the problems concerning the drinking water, these matters are supervised by the World Health Organization (WHO) with offices in Geneva. In response to WHO a proposal of requirements for raw water quality which is suitable as the source of drinking water has been elaborated [40-44]. 

As reported in Table 3.52 maximum requlations have been set for only six anthropogenic organic compounds and total trihaJomethanes. It is anticipated that this list will be expanded as the health risks of other synthetic chemicals are evaluated. 

Recently, a number of volatile organic compounds have been detected in groundwater supplies. The presence of these compounds is serious because many of them have been found to pose a carcinogenic or mutagenic risk to humans. The gravity of the problem is compounded by the long residence time in groundwater aquifers. 

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