Concentration of Nitrate, Nitrite and some other Parameters in Drinking Water Wells, Talesh(Northern IRAN), 2011

Abstract Nitrate is one of the important indices of drinking water quality. Its concentration can be increased by improper wastewater disposal and extended application of synthetic fertilizers، especially in aquifers with high level underground water. This study has been designed to determine the concentration of nitrate and nitrite in Talesh drinking water wells. Based on the geographical conditions، probable pollution sources and placement of the wells، 15 wells were selected as appropriate representatives of the ground water resources. During the autumn 2011، 60 samples (4 samples from each well with approximately 3 week intervals) were analyzed by standard procedures for Nitrate، Nitrite، Ammonia، Salinity، Total Dissolved Solids، Electrical Conductivity، pH and Temperature. The results indicated variation in nitrate levels from 1. 46 to 10. 27 mg/l as NO3 and variation in nitrite levels from 0. 009 and 0. 128 mg/l as NO2. The concentration of nitrate and nitrite in all the samples were lower than the Iranian standards (50 mg/L as NO3- and 3 mg/L as NO2-). On the basis of pollution definition، all the wells could be classified as “weak polluted” in terms of nitrate concentration. In addition، the observed differences between the wells of the region and also rising of the concentration of nitrate in some wells to 13 mg/l (the so-called human affected value)، need to be closely considered and cared for. Conflict of interest: non declared