The quality of the available
untreated water must be so good, that reasonable effort can be used to
convert it into drinking water which fulfils the valid rules and regulations.
The upper limits of reasonable effort are defined in Europe for three categories
of effort by the EG Guideline for Untreated Water [21]:
they are also used in Germany therefore. As a rule, at least mesotrophic
conditions are sought after in a lake or reservoir in order to encounter
problems caused by development of algae quantities, oxygen starvation and
re-dissolving processes. Nitrogen compounds and especially phosphor determine
the trophy of the waters. Organic and inorganic pollutants (solvents heavy
metals, nitrate) which cannot be removed from untreated water, or can only
be removed with difficulty must not be found or may only be found below
the limiting values of the valid Drinking Water Decree [24].
Table:
Examples for limiting values according to the German Drinking Water Decree
[15],
(Trinkwasserverordnung [15]) already guaranteed
for untreated water
| Criterion |
Unit |
Limiting
value |
| Calcium |
mg/L |
500 |
| Nitrate |
mg/L |
50 |
| Oxidizability
(COD) |
mg/L |
5 |
| Aluminium |
mg/L |
0,2 |
| Mercury |
mg/L |
0,001 |
| Pesticides (total) |
mg/L |
0,0005 |
| PAK (total) |
mg/L |
0,0002 |
| PSM (indiv.
subst) |
mg/L |
0,0001 |
Richtlinie des Rates vom 16. Juni 1975 über die
Qualitätsanforderungen an Oberflächenwasser für die Trinkwassergewinnung
in den Mitgliedsstaaten (75/440/EWG): Amtsblatt der Europäischen Gemeinschaften,
Nr. L 194/34-39, 25.07. 75 geändert 9. 10. 1979.
Trinkwasserverordnung in der Fassung vom 5. 12. 1990
BGBl. der BRD I
© | Dipl.-Biol.
Hartmut Willmitzer | 31.07. 2000 | Copyright
