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The World Health Organization
The World Health Organization (WHO), set up some guidelines for
drinking-water quality which are the international reference point for
standards setting and drinking-water safety. The latest guidelines drew up
by the WHO are those agreed to in Geneva, 1993.
Click here for the WHO's
drinking-water standards.
You will notice that there is no guideline for some of the elements and
substances which are taken into account. This is because there have not been
sufficient studies about the effects of the substance on the organism, and
therefore it is not possible to define a guideline limit. In other cases,
the reason for a non-existing guideline is the impossibility of that
substance to reach a dangerous concentration in water, due to its
insolubility or its scarcity.
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The European Union
The European Union drew up the Council Directive 98/83/EC on the quality of
water intended for human consumption, adopted by the Council on 3 November
1998. This was drawn up by reviewing the parametric values of the old
Drinking Water Directive of 1980, and strengthening them where necessary in
accordance with the latest available scientific knowledge (WHO guidelines
and Scientific Committee on Toxicology and Ecotoxicology). This new
Directive provides a sound basis for both the consumers throughout the EU
and the suppliers of drinking water.
Click here for the EU's
drinking water standards.
These
were the main changes in the parametric values:
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Lead: The guideline was reduced from 50
µg/l to 10 µg/l, and a transition period
of 15 years was defined to allow
replacing of lead distribution pipes.
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Pesticides: The values for individual substances and for total pesticides were
retained (0.1µg/l / 0.5µg/l),
plus additional, more stringent values were
introduced for certain pesticides
(0.03µg/l).
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Copper: The value was reduced from 3 to 2 mg/l.
- Some new standards were
introduced for new parameters like trihalomethanes,
trichloroethene and
tetracholoroethene, bromate, acrylamide etc.
Click here for comparative table for WHO's and EU's water
standards.
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