<p>Groundwater nitrate contamination in India shows strong spatial asymmetry, with severe pollution concentrated in northwestern, central, and southern states, driven by high nitrogen loading and limited hydrological flushing. Multivariate analysis from Karnataka indicates that anthropogenic inputs, groundwater extraction, and shallow water tables strongly co-vary with nitrate levels, while rainfall provides the dominant natural dilution control. Isotopic evidence across major river basins reveals mixed nitrate sources—fertilizers, soil organic nitrogen, sewage, and manure—varying with climate and hydrogeology. Comparative assessment of four districts demonstrates that lithology, vadose-zone thickness, and monsoon-driven anoxia jointly regulate natural denitrification potential and nitrate transport velocity. Health risk analysis shows that exposure is shaped not only by contamination levels but also by water-use patterns, demographics, and correct reference dose selection, with standard parameter assumptions often inflating risk estimates. Mitigation requires integrated strategies: precision nutrient management, climate-smart fertilization, improved irrigation control, decentralized sanitation with nutrient recovery, and context-appropriate nitrate treatment technologies ranging from biosorbents to biological denitrification systems. Together, these findings highlight the need for region-specific interventions that align hydrogeological constraints with demographic exposure patterns to effectively reduce nitrate risks.</p>