The WHO Guidelines for Drinking-water Quality (WHO, 2004)
cover a significant number
of potential substances from water treatment or distribution, but
only a few of these substances are of practical significance. It is
important that water supply
agencies properly manage any chemicals that they use. In many cases, the
best method of
control is through management practices, such as optimization of the
treatment process, and
regulation of materials and chemicals that come into contact with
drinking-water, rather than
through monitoring and chemical analysis.