Groundwater survey in the northern and southern part of the Ganges river of Bhagalpur district have been found to contain arsenic above the permissible limit, 0.05 ppm as per guidelines of WHO. This area of middle Ganga plain has high potential aquifers known for intensive arsenic contaminated groundwater extraction for irrigation. Most of the arsenic contaminated samples of this area contain arsenic more than permissible limit at the depth of 90 feet to 100 feet. The groundwater samples also contain iron. The soil characteristics of this area are coloured organic-rich argillaceous sediments. Some analysis have been carried out for fluoride in the southern parts of the Gangetic plain. The samples were found to contain fluoride more than permissible limit. Dugwells have been analysed for arsenic and fluoride. Dugwells may be arsenic safe water in arsenic affected areas. The interaction of groundwater with the surface water causes weathering as a result of which accumulation of arsenic in thee aquifers takes place.