In India, the increase in foodgrain production from 50.8 million t (1951-52) to 203.6 million t (1998-99) is mainly attributed to the adoption of high-yielding crop varieties and use of fertilizers. Consequently, fertilizer consumption during the corresponding period increased from a mere 0.55 kg ha-1 to 90.04 kg ha-1 (FAI 1999). The increased use Quality of shallow water table as affected by long-term fertilizer use in the rice-wheat system and/or misuse of fertilizers had frequently been cited as the cause of water quality deterioration (Miller 1979). Nitrate leaching can occur in intensively cultivated areas with a shallow water table (Bajwa et al 1992). In the face of increasing food demand of the burgeoning population, efficient fertilizer use in crops and the prevention of groundwater pollution are critical (Singh and Sekhon 1976). In the tarai region of Uttaranchal, the water table is shallow (about 1 m deep) and rice-wheat is the predominant cropping system. Since the inception of this long-term experiment, no study on groundwater quality has so far been conducted. This study aimed to monitor the impact of continuous fertilizer use (more than 30 y) under intensive cropping on the nutrient enrichment of groundwater.