Introduction: Given that groundwater resources are the main water sources of Germi city, it is necessary to ensure its compatibility with drinking water standards. The aim of this study was to determine water quality index (GWQI) for Germi city and zoning with GIS on the basis of WQI index.
Methods: This study was a descriptive-analytical one and lasted for 14 month. Sle were taken from 5 wells monthly between November 2013 until November2014. All sles then were transferred into Ardabil water and wastewater laboratory and following parameters were analyzed: total dissolved solids (TDS), Chloride, Calcium Magnesium, Sulphate and Sodium on the basis of procedures of standard methods book. Then, ground water quality index (GWQI) was determined with above mentioned parameters. Finally, zoning map of WQI index in Germi city was prepared with GIS.
Results: The results showed that GWQI of Germi city is between 41.37 and 44.86, thus water quality is good. Lowest GWQI value is for Aranchi well (41.37) with highest quality and the highest GWQI value is for Godeh Kahriz (44.86) with lowest quality. Also all parameters are in standard ranges.
Conclusion: The study showed that ground water quality of Germi city is good but Ca and Mg level is low, thus it is necessary to deliver these two micro nutrients to human from other resources or with adding them in water treatment plant.