Water Quality in Slovenia - Agencija RS za okolje

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W A T E R Q U A L I T Y I N S L O V E N I A
Divje jezero Krupa spring
Based on statistically treated results, the chemical status of a groundwater body is assessed every
year. For each parameter, annual arithmetic mean values (AM) are calculated at individual monitoring
sites. From the annual arithmetic mean values of individual monitoring sites, the representative
average value for a groundwater body is calculated (AM ), where each monitoring site is weighted
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proportionally to the catchment area.
A good groundwater body chemical status is assessed if the following requirements are fulfilled:
• for all parameters at all monitoring sites within the groundwater body borders, the following
applies: AM ≤ QS (quality standard)
or
• for all parameters for a groundwater body, the following applies: AM ≤ QS,
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• drinking water pumped from the groundwater body is compliant with the requirements set out in
the Rules on Drinking Water,
• there is no indication of salt water intrusion into the groundwater body,
• groundwater pollution does not deteriorate the status of surface waters and does not have
damaging effects on neither terrestrial nor aquatic ecosystems.
Out of 15 groundwater bodies where national monitoring network and monitoring sites are
situated, chemical statuses of 9 groundwater bodies were determined in 2006. In four groundwater
bodies, the chemical status was only estimated, while for two groundwater bodies the network was
not representative enough for evaluation. The chemical status of groundwater bodies in 2006 is
presented in Map 12 and in Table 17, together with an indication of the parameters causing a bad
chemical status, and the polluted parts of a groundwater body. A bad chemical status assessed on
the results for groundwater as well as on the monitoring results of drinking water was determined
for three groundwater bodies: the Dravska kotlina, the Murska kotlina and the Krška kotlina. In the
Drava and the Krška kotlina, a bad chemical status was assessed due to nitrates and pesticides that
are characteristic of agricultural activity, while in the Murska kotlina, additionally due to chlorinated
derivatives of ethene that are still used in industrial and trade activities. In 2006, a bad chemical status
of the Krška kotlina was determined for the first time.