Water quality standards

Posted: 24 January 2001

Acceptable standards for water quality have been developed at both the national and international level. The World Health Organisation (WHO) has published guidelines for drinking-water quality, for example, and the European Commission has produced a directive which applies to the quality of water intended for human consumption. Elsewhere all developed nations have established standards for water quality, and some progress has been made among the developing nations. Published standards typically include maximum allowable concentrations (MACs) of specific toxic elements - for example, heavy metals - and guide levels (GL) for those considered less harmful - for example, acidity or calcium (Ca).