Groundwater is one of the main water supply sources in arid and semi-arid regions, and its quality decline can be serious threat to society. Therefore, the use of pollution maps is effective tool in water resources management. The Tabriz plain, as semi-arid region, has faced groundwater quality degradation in recent years. In this study, data from 41 wells over 15-year period (2007–2021) were collected from East Azerbaijan Regional Water Authority, and groundwater quality was analyzed using Water Quality Index (WQI), Irrigation Water Quality Index (IWQI), and geostatistical methods (Kriging and IDW) in ArcGIS. The WQI results showed values between 119.23 and 761.24 in wet season and between 101.70 and 747.89 in dry season, indicating poor to unsuitable drinking water quality. IWQI values ranged from 22.79 to 71.32 in wet season and from 22.85 to 75.40 in dry season, placing water in severe to slight restriction for irrigation. Seasonal comparison revealed an improvement of 4.44% in drinking water quality and 1.86% in irrigation water quality in dry season compared to wet season. Analyses with AqQA showed that the hydrochemical facies was sodium–chloride (Na-Cl), with these ions playing the main role in quality reduction. The Wilcox diagram indicated that in both seasons most samples were in the high salinity and sodium hazard group, unsuitable for irrigation. Geostatistical zoning showed that the highest pollution was concentrated in southwest and northeast of aquifer. Finally, optimal groundwater management, regular monitoring, and soil salinity reduction are proposed as solutions to improve water quality.