Hydrogeochemical Characteristics and Evaluation of the Drinking and Irrigation Water Quality in Marand Plain, East Azerbaijan, NW Iran

In order to study hydrogeochemistry of groundwater, samples of water were collected from Marand located in Eastern Azerbaijan province, NW of Iran at July, 2008. This region has 800 km2 space and 87 locations. Samples which were collected from 74 water wells, 10 Qantas and 3 springs analyzed for major cations and anions processed by statistical methods. Parameters were compared with water quality standards and public health standards for domestic usage. Some of the locations are defined by high concentration of EC, TDS, Cl, Na and K. Half of the groundwater samples were contained Ca-Mg-Cl type of hydrochemical facies, followed by Ca-HCO3, Ca-Cl and Na-Cl types. Based on US salinity diagram, 42% of the samples fall in the field of C3-S1. Due to low sodium and medium-high salinity groundwater C3-S1 class can be used for irrigation on almost all soils with little danger of sodium problem. Majority of the samples are not suitable for domestic purposes meanwhile they were far from standards of drinking water. In the recent years, comparing average electrical conductivity and total dissolved solids of the studied area revealed that declines in water levels as a result of extensive agricultural activities and urbanization resulting in deterioration of groundwater quality in the major parts of the plain.