Hydrogeochemical characteristics and quality assessment of groundwater in Naini Industrial Area, Uttar Pradesh, India

Seasonal studies have been conducted on the groundwater geochemistry of the Naini Industrial Area to understand the geochemical processes influencing water composition. Analytical findings reveal that the groundwater in the research area ranges from slightly acidic to alkaline, with calcium (Ca²⁺) and sodium (Na⁺) prevailing the cationic composition, while bicarbonate (HCO₃⁻) and chloride (Cl⁻) dominate among anions. The lowest ionic concentrations are during the monsoon and the highest in the pre-monsoon season, owing to dilution from increased rainfall during the monsoon season. The predominant water type identified in the study is Ca–Mg–HCO3 across all the sampling seasons. Analysis using the Gibbs diagram indicates that rock weathering plays a significant role in regulating the chemistry of groundwater in the Naini Industrial Area. Additionally, the ratios of (Na⁺ + K⁺)/TZ⁺ and (Ca²⁺ + Mg²⁺)/(Na⁺ + K⁺) emphasise significant ionic contributions from both silicate and carbonate weathering processes. In the pre-monsoon season, groundwater is oversaturated with calcite and dolomite, while in the post-monsoon and monsoon seasons, it is undersaturated. The Principal Component Analysis (PCA) suggested the distinct components linked to the geogenic natural sources (rock–water interactions) and anthropogenic contamination (agricultural activities). PCA accounted for approximately 80.2% of the total variance in the major ion dataset, accurately describing the underlying processes affecting the chemistry of groundwater. The analysis revealed the existence of both geogenic and the probable anthropogenic sources. The findings of the study can yield important insights for decision-makers in developing efficient tactics for the present and future management of the groundwater quality in the region.