Question raised in Lok Sabha on Contamination of Ground Water, 01/12/2016. Ground water quality data generated by Central Ground Water Board (CGWB) during various scientific studies and ground water quality monitoring indicates that ground water in isolated pockets in parts of various States including Delhi and Bihar is contaminated with Fluoride, Nitrate, Arsenic, etc.The number of Blocks in each State, affected with ground water contamination are given at Annexure-I.