Current Status of Ground Water Arsenic Contamination in India and Recent Advancements in Removal Techniques from Drinking Water

India is consisting of 29 states and 7 union territories, including a national capital, Delhi. Elevated concentrations (>10 g l ) of arsenic (As) in ground water (GW)  -1 of many states of India have become a major concern in recent years. Up to now about 0.2 million GW samples have been analyzed for As contamination from all over India by various researchers and Government agencies. About 90% of these cover only the Eastern part of India while several states and UTs are still unexplored. However, from the available data, GW of eighteen Indian states and three union territories has been found to be As contaminated to different extents through natural or anthropogenic origin. Among these, As >300 μg l has been reported from at least one locality from fourteen states. The -1 maximum level of As (7350 μg l ) in GW has been reported from a highly industrialized -1 area, Patancheru in Medak district of Andhra Pradesh. However, the gravity of problem is more in West Bengal followed by Bihar and Uttar Pradesh. Five out of eight North-Eastern states are also affected by As contamination. Manipur is ranked first and Assam as second followed by Arunachal Pradesh, Tripura and Nagaland. The GW in these regions is naturally As enriched, and therefore wide spatial distribution of As has been found in these areas. In North India, Punjab and Haryana and in South India, Andhra Pradesh and Karnataka are suffering with GW As contamination. Low level of As (up to 17 μg l ) has also -1 been reported in Tamil Nadu from South India. Many of the states like Jammu and Kashmir, Uttarakhand, Odisha, Gujrat, Kerala, Telengana, Goa etc. are still unexplored for GW As contamination. Thus, according to current reports out of 640 districts in India, 141 are As affected (As >10 g l-1), among them 120 are above 50 g l-1. Considering its severity, the issue of As contamination in drinking water has been taken up by the Government of India and mitigation efforts are being initiated. In order to provide safe drinking water, different agencies/ organizations have developed eco-friendly, cost effective devices/ filtration techniques having higher As removal capacity. Here we elucidated the current status of GWAs contamination in different states of India and the new developments of mitigation options.