bids are invited for custom bid for services - cleaning of filter bed ,raw water tank, underground storage tank and overhead tank at water supply complex of balanda colony and jagannath colony of jagannath ocp under jagannath area for period of two years re-tender/2nd ca.. - cleaning of raw water tank of filter plant/pump house including rubbing & cleaning walls & base and disinfecting with bleaching powder etc. and disposal of waste material to a lead of 50 m all complete as per instruction of eic , cleaning of under ground sump, over head r.c.c.tank( independent staging) including disposal of slit and rubbish, all asper directionof engineer-in-charge. the cleaning shall consist following operations:-(i)tank shall be emptied of water by pumping & bottom shall be cleaned of silt and other deposits.(ii)entire surface area of the sump shall then scrubbed thoroughly with wire brush etc.and pressure washed with water. (iii)chlorination of rcc internal surface by liquid chlorine. (iv) the treated surface shall be dried using air jetting and all loose particles shall be removal from the surface. (v) finally the surface shall be treated with ultraviolet radiation etc as per direction o fengineer-in charge , carriage of materials:earth lead 5 km