assessment of the effect of human and industrial activities on groundwater within the city of khoy

background : the present paper aims to study the effect of human and urban activities on the quality of groundwater within the city of khoy in terms of heavy metals, chemical salts, and minerals from the geological formations of this region. methods : samples were provided from 32 pumping wells and the concentration of heavy metals ( cd, cu, mn, pb, zn, fe, as, and b), the main ions (hco 3 ,so 4 2- ,cl - , mg 2+ ,ca 2+ , na + ), and no 3- were measured. in addition, tds, ec, th, and ph were recorded. for this purpose, graphite furnace atomic absorption, titration, and potentiometric methods were used. the obtained concentrations and values were compared with the approved standards for drinking water and agricultural water. results : concentration of most minerals, trace elements, and major ions showed dramatic increase in groundwater of eastern region of khoy. thematic maps produced using gis on concentrations of heavy metals and major ions showed that the concentration of trace elements such as lead, chromium, and manganese and also sulfate and nitrate within the city of khoy is higher than the western region of khoy, which would be due to pollution caused by urban wastewater. conclusions: unfortunately, due to the lack of correct and principled development of sewage discharge system, especially in industrial and critical areas and discharge of domestic and industrial wastewater into the absorbent wells, the risk of groundwater contamination is strongly felt in the city of khoy.