<b>Arsenic Contamination of Ground water and Health Risk</b> The arsenic poisoning due to contaminated groundwater in West Bengal, India, and all of Bangladesh has been thought to be limited to the Ganges Delta despite early survey reports of arsenic contamination in groundwater in the Union Territory of Chandigarh and its surroundings in the northwestern Upper Ganga Plain and recent findings in the Terai area of Nepal. Groundwater arsenic contamination and sufferings of people have been reported in 20 countries in different parts of the world. The magnitude is considered highest in five Asian countries and the severity is in order of Bangladesh India Mangolia China Taiwan. In all these countries, more and more groundwater withdrawal is taking place because of increase in agricultural irrigation. In India Maximum arsenic content was observed in bhojpur bihar ,. The groundwater of Bihar states is affected with arsenic contamination. A long term environmental planning is essential to blunt the danger from such pollution. Analyses of the arsenic content of 206 tube wells showed that 56.8 exceeded arsenic concentrations of 55 micro g L, with 19.9 300 micro g L, the concentration predicting overt arsenical skin lesions. On medical examination of a self selected sample of 150 person, 13 of the adults and 6.3 of the children had typical skin lesions, an unusually high involvement for children, except in extreme exposures combined with malnutrition. The urine, hair, and nail concentrations of arsenic correlated significantly with drinking water arsenic concentrations up to 1,648 micro g L. On neurologic examination, arsenic typical neuropathy was diagnosed in 65 of the adults, a prevalence previously seen only in severe, subacute exposures. We also observed an apparent increase in fetal loss and premature delivery in the women with the highest concentrations of arsenic in their drinking water. The possibility of contaminated groundwater at other sites in the Middle and Upper Ganga Plain merits investigation. Arsenic poisoning culminates into potentially fatal diseases like skin and internal cancers. This paper reviews sources, speciation, and mobility of Arsenic and global overview of groundwater contamination. The critically reviews the Arsenic led human health risks, its uptake, metabolism, and toxicity mechanisms. Our research provides an overview of the state of the art knowledge on the alternative Arsenic free drinking water and various technologies oxidation, coagulation flocculation, adsorption, and microbial for mitigation of the problem of As contamination of groundwater. Ground Water, Surface Water, Physico Chemical Parameters, Arsenic, Health, Ganga, toxic 836-842 Issue-4 Volume-2 Sanjay Kumar Verma | Dr. Ajay Kr. Upadhyay