desilting and cleaning of master sewer line of various sizes in leg - iv (part) along spr from sector 49/50 to 55/56, gurugram. removing of blockage and desilting of master sewer line of various sizes by high power super sucker mechanical device including cctv survey and repairing of manholes as per site requirement along spr from sector 49/50 to 55/56, gurugram and all other works contingent thereto. (2nd re-call) .