At present a total of 1500 GWMWs are monitored representing almost all the blocks of twenty three districts of the states of West Bengal. Due to inaccessibility in Andaman group of Islands, initially the task was taken up with the help of a few GWMWs but gradually the number of stations have been increased to 113. However, at present no GWMW has been established in Nicobar group of Islands and in Little Andaman, due to their inaccessibility. Periodic ground water level measurements were taken up four times in a year in 2020-2021, (i.e. in the month of April, August, November and January) in West Bengal and two times in a year (i.e. April and November) in Andaman group of Islands. The scientific officers and technical personnel of the Eastern Regional office, systematically collected field data throughout the year. While the chemists have analysed the water samples collected from GWMWs to adjudge the variation of chemical quality of groundwater in the state and occurrence of toxic minerals. This report attempts to compile the collected data during 2020-2021 and present its detailed analysis in a comprehensive manner in the form of maps and statistical analysis and brought out in two sections, where Section-A embodies report for West Bengal and Section-B forms report for Andaman group of Islands.