Nitrate Pollution of Wells in the Villages along Niraj (Nyárád) River

Zoltán Hajdu and György Füleky

Szent István University, Institute of Environmental Sciences, Department of Soil Science and Agricultural Chemistry, Gödöllõ, Hungary

Corresponding author: Zoltán Hajdu, drd
    str. Cuza Voda 83
    Târgu Mures, Romania
    Telephone: + 40 744 774897
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    E-mail: zhajdu@rdslink.ro

CEJOEM 2007, Vol.13. No.3-4.: 323-333


Key words:
methaemoglobinaemia, drinking water, nitrate pollution, catchment area, individual wells, water table


Abstract:
In the studied area of Transylvania there are no deep water resources and there are many small localities where in the near future no central water system development is expected and the individual shallow wells will probably be used for a long time. In this respect it was crucial to follow the evolution of the nitrate pollution of the water in individual wells in 17 localities in order to get a comprehensive overview of the nitrate pollution of the groundwater in the studied catchment area.
    The present study is evaluating the nitrate pollution of the water in the individual water sources in the catchment area of the Niraj (Nyárád) River. Out of the 355 wells sampled, 152 (43%) exceeded the nitrate concentration standards of the EU (50 mg/l). An unequal distribution of the nitrate pollution in the studied catchment area was identified: there was less severe pollution of the groundwater in the upstream part than in the downstream area. There were significant differences in the nitrate concentrations between the sampling points in the higher part of the catchment area, over 350 m, and those in the lower part, under 350 m. In the lower part the nitrate concentration of 66% of the samples exceeded the 50 mg/l limit value while in the upper part, the nitrate concentration was above 50 mg/l only in 26% of the sampled wells. There were villages in the downstream part where about 90% of the evaluated wells had higher concentration of nitrate than the standard value and localities situated along the tributaries where the individual wells were less polluted, where only 12% of the wells exceeded the 50 mg/l concentration.
    In the studied area the nitrate pollution of the water from the wells was found to be an important problem because the area is one of the highest populated areas of Transylvania and the nitrate concentration in the wells is still increasing which needs a permanent alert to methaemoglobinaemia.


Received: 18 January 2008
Accepted: 7 July 2008

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