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In general, water from the artesian wells has obviously a better quality (less organics, chlororganics and nitrates) than water from the tap or compared to water from shallow village wells.
That water is rather warm (12 -15 oC),
even in winter. The redox potentials (oxidation state) vary distinctly
and sometimes a bad smell similar to rotten eggs (H2S) can be
detected. This type of smell usually has natural reasons and
lasts only a few minutes. Other natural compounds can also occur in
high concentrations above drinking water limits; information was
published by the Institute of Colloid and Water Chemistry in Kiev.
nitrate concentrations (NO3-N in the figure below) are usually
low, the same is true for the organic load of this water (controlled by
measurements of SAC254 in 1/m). But exceptions are possible (see figure) - at least for some time. The reason for this is not always known.
The wells are officially controlled, but nevertheless, pollution already occurs
and is not always detected. In a few cases, we have detected
chlororganic compounds (up to 300 microgram AOX per litre - see
figure!). As long as they have not yet been identified, one has to take
into account that they are dangerous or even very dangerous for human
health. (s. literature)! To get an official statement about the
possible occurrence of those compounds, you should ask the city water
authorities, Vodocanal and "SanEpidemStanzije", (SES).
measurements in June 2000 showed that the problem still exists, the
concentrations of chlororganics were however smaller than in former
contamination of these water resources, because of more and more holes
having been drilled into the underground (and possibly because of sewer
leakage), is not acceptable at all and would have been possible
to avoid or at least to be minimised. The water authorities should
recognise their responsibility for this fact. The official
controls should include chlororganic and other toxic organic compounds
and not only harmless substances like sulphate, carbonate etc. the
concentration of which is indicated on tables above the well. This
could perhaps help to regain the trust of the consumers.
Nevertheless, problems of tap water quality have to be solved in the water work (rather than drilling more and more holes)!!!
Additional information for water experts:
EC = electr. conductivity given in mS/m;
NO3-N (nitrate) is given as nitrogen in mg/L, but concentrations are usually < 1 mg/L;
(in 1/m) is the spectral absorption coefficient at 254 nm per meter;
this measurement allows to estimate the organic load: if results >
10 1/m are detected, the type of load should be clarified.
AOX: adsorbable organic halogens in microgram/L Cl.
The plot shows the medium, 25% and 75% percentile and min./max. values
Analytical information sources are given in the overview of methods