For groundwater based piped water supply scheme, while sinking the big dia. tube wells every effort is taken to place the strainer at an Arsenic-free aquifer. But, due to the unpredictable nature of this geogenic pollutants, it is never can be assured that Arsenic-free aquifer can be trapped while sinking the tube well. Also, Arsenic pollution may be encountered on a later date due to the spreading of Arsenic in other areas as well as in other layers underground. Therefore, it is often necessary to provide Arsenic & Iron Removal Plant (AIRP) to cater this crisis, if evolved, for supplying Arsenic-free water to the consumers. Under the Arsenic Master Plan, 165 nos. of AIRPs were proposed for implementation and the work is at an advanced stage of completion. Fund from NITI Aayog is also being utilized to finish the remaining works. Apart from the Master Plan schemes, Public Health Engineering Department, Govt. of West Bengal has already implemented a good number of AIRPs in other schemes where the source tube wells on a later date have been found to be yielding Arsenic-laden water. Public Health Engineering Department, Govt. of West Bengal is implementing IRPs with indigenous technology, developed in consultation with Arsenic Task Force, Govt. of West Bengal. Mainly 2 (two) types of models, viz. Modified Sujapur-Sadipur Model (capacity 20m3/hr. – 170 m3/hr.) & Gobardanga Model (low capacity – 5 m3/hr. - <20 m3/hr.) have been adopted.