operation and maintenance of stp sewerage treatment plant at nigalpani township , dgps , dharchula , operation and maintenance contract of sewerage treatment plant of capacity 200 kld which includes . 1 . sewerage lift pump set ( 1 working + 1 standby ) , 2 . air blower with accessories ( 1 working + 1 standby ) , 3 . sludge recirculation pump ( 1 working + 1 standby ) 4 . treated water lifted high pressure pump ( 1 working + 1 standby ) 5 . dosing system with pvc tank ( 1 working + 1 standby ) , 6 . treated water pumping station with multigrade media pressure & activated carbon filter . 7 . cleaning of screen grit for screen chamber and providing material/chemical used for filtration and disinfecting the plant in all respect at township , nigalpani at dgps , supply of chemical for the smooth running of stp em solution and sodium hypo ( chlorin powder ) , visit of site engineer/expert once in month