42 of 74  Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 3: Plant Description  control room including operator's office shall be located in dewatering building. This room shall be  built at a suitable location of the dewatering building, providing monitoring and remote control of the  equipment by the operators. The dewatering building shall contain one European water closet one  squatting water closet, one urinal bowl and two sinks. The complete dewatering facilities shall be locally and automatically controlled and monitored on the  SCADA system. Local control devices and/or panels for dewatering / thickening equipment including  a local control center of SCADA system shall be placed in this operation room. All sludge shall be treated in the dewatering facilities. The sludge shall be pumped by frequency- controlled eccentric screw pumps for sludge feeding. A lifting system with overhead travelling crane  shall be provided to carry out the maintenance works of dewatering facilities.  Supernatant from dewatering process (es) shall be delivered back to the system by gravity as possible.  The mixture of supernatant with drainage water and sewerage generated in the WWTP is not  permitted.  The polymer shall be used for conditioning of the sludge. The polymer shall be prepared in a polymer  generation unit. The polymer generation unit shall allow either liquid or powder polymer to be  diluted/dissolved to a predefined concentration and automatically mixed and matured. The polymer  generation unit shall be a stand-alone unit and shall be automatically controlled locally by a local  control panel. The minimum storage capacity of polymer shall be 30 days. The Contractor shall inform  details and type of polymer before taking over.  The polymer shall be dosed by means of eccentric screw type pumps controlled by frequency  converters. Washing water shall be connected to both the suction and discharge lines of the polymer dosing pumps  and decanter feeding pumps. In addition, the service water line shall be installed to the appropriate  places of the sludge thickening and dewatering building and sufficient number of connection points  shall be supplied. The treated water should be used for this watering.  Dewatered sludge shall be conveyed by fully closed suitable conveyors equipped with an appropriate  drainage system and designed to prevent leakage to a level and a position that allows the sludge to be  dumped. Final destination of the dewatered sludge shall be the sludge drying units. Conveyor system shall  transfer the dewatered sludge to directly sludge drying facility. However, transfer to one of the  containers devoted for dewatered sludge and/or directly to sludge storage area shall also be considered  for emergency cases.  In order to remove backwash water that will be generated during backwashing from the system  without taking to the conveyor, a suitable hydraulic or pneumatic lid system to decanter’s sludge outlet  chute will be built. The compressors required for the decanter will be fixed (not mobile) and the piping  will be made according to the criteria specified in the mechanical specification.  3_Vol3_d4.3_Section 3_Plant Description_GIR_rev08  Minimum number of centrifuges  : 2 (1 duty + 1 stand-by) units  Minimum number of digested sludge feeding  : 3 (2 duty + 1 stand-by) units 