Complete operation and maintenance of one No. 0. 4 MGD Horizontal Pressure Filter, one No. 0. 4 MGD Rapid Sand Gravity Filter and one No. 0. 6 MGD vertical pressure filter at Garden Reach including chlorination arrangements and cleaning of RCC overhead/ under ground tank at GRC Complex for a period of 03 Years ( i.e. 36 months ) under Sr. Section Engineer ( Water Supply ) at GRC.