31 of 74  Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 3: Plant Description  All air piping shall not be buried. All required piping from blower building up to the water level in  aeration tank shall be in stainless steel and rest of air pipe shall be HDPE 100 PN 16 considering the  external physical impact. For the calculation of the blower capacities, the minimum required O$_{2}$ concentration in the tanks, peak  factor for carbon or nitrogen load (whichever the highest), and maximum wastewater temperature,  maximum ambient temperature of 45  C at 50% relative humidity, water depth, diffuser performance,  static head and dynamic friction losses and complete mixing of aerobic zone must be taken into  consideration. The performance data of the blower and diffuser shall be submitted together with the  tender. The blower building shall be provided a proper ventilation in accordance with “Heating and  Ventilation” section of this document.  3.3.4.19 Primary Sludge Pumping Station The primary sludge pumping station shall be designed, constructed and equipped regarding the  requirements set in Table 2-1. The settled sludge shall be pumped to the gravity sludge thickeners via primary sludge pumps. A  sludge screen to be located top of the gravity sludge thickener shall be installed on discharge line of  the primary sludge pump. A means of control on sludge suction from the each individual clarifier shall  be provided by electrically actuated devices. The requirements for the drainage, foul air collection and clean water supply system stated in Section  3.3.4.34 and 3.3.4.35 should be met for the primary sludge pumping station inner area. The pumps for primary sludge shall be dry mounted and placed in the primary sludge pumping station.  The pumps shall be positive displacement or progressive cavity pumps. The capacity of the primary  sludge pumps shall be calculated according to the settleable solids amounts at the maximum flow and  maximum operation of 24 hours/day. A frequency converter and dry running protection system shall  be provided for each pump. Washing water shall be connected to both the suction and discharge lines of the sludge pumps. This  washing system will engage automatically when the pumps are not operated. In addition, the service  water line shall be installed to the appropriate places of the primary sludge pumping station and  sufficient number of connection points shall be supplied. The treated water should be used for this  purpose.  Macerators shall be used to macerate the solid and fibrous components in the primary sludge. For each  pump, one macerator shall be supplied and installed on the suction pipe of the pump. A permanent crane or lifting system shall be provided to carry out the maintenance works for primary  sludge pumps. 3_Vol3_d4.3_Section 3_Plant Description_GIR_rev08  Minimum number of primary sludge pump  : 2 (1 duty +1 standby) units  Minimum number of macerator : 2 (1 duty +1 standby) units Design of operation hour of the primary sludge pumps  : 24 hours/day