<p>Regular assessment of groundwater quality is crucial for ensuring its safety for drinking and irrigation by detecting and managing potential contaminants. The objective of this investigation was to assess the purity of groundwater in Lucknow, India, to ascertain its suitability for these purposes. Key water quality parameters, such as pH, turbidity, total dissolved solids, alkalinity, hardness, and nitrate levels, were analyzed after a total of 20 samples were collected from various locations throughout the study area. The weighted arithmetic WQI method was implemented due to its capacity to simplify intricate water quality data into a singular index, thereby enabling easier interpretation and comparison. Kriging method was chosen for spatial mapping because of its capacity to incorporate spatial autocorrelation and generate statistically optimized predictions with estimation uncertainty, thereby providing a higher level of precision than more straightforward interpolation methods, such as IDW. The findings revealed that WQI values in the study area ranged between 39.08 and 90.23. To better contextualize the WQI changes, the main sources of contamination, such as sewage intrusion, industrial discharge, and agricultural runoff, were chosen based on the observed data. While most locations showed good water quality, the Triveni Nagar region was identified as unfit for drinking. The water quality map indicates that approximately 35% of the area falls under the good category, 55% under good to poor, and 10% is classified as unfit for drinking. To raise public awareness and inform policy efforts, mitigation techniques such as the encouragement of rainwater collection, controlled fertilizer utilization, and improved wastewater management can be beneficial. These results suggest that groundwater in the region is generally suitable for both drinking and irrigation, with some localized concerns that require attention.</p>