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Contractor shall be in accordance with the specifications given in Section 7.8.25. The screening press and perforated screens shall be cleaned with hot water (minimum 60$^{0}$C). The screen building shall contain one squatting wastewater closet, one urinal bowl and one sink. 

The screens shall be made from stainless steel 1.4404 in order to prevent corrosion. 

The cleaning mechanisms of the fine screens shall be automatically operated by water level sensors (ultrasonic level or radar type sensor) located upstream and downstream of the screens (level difference). In addition to this, the cleaning mechanisms for the fine screens shall be operated by time intervals. Time intervals must be adjustable from the SCADA. 

An area to be used for container station with sufficient service water taps shall be provided for handling and washing the containers. Water used for cleaning purposes of containers shall be properly gathered from the bottom drainage pipe and should be conveyed to the inlet pumping station. 

The fine screens, with their screening containers, screening press and conveyors shall be located in a building with frost-free conditions. . 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 building inner area. 

The fine screens shall be locally controlled and operate as autonomous units. The operation status, however, should be monitored and controlled by the SCADA system. Furthermore, water levels in front of and behind the fine screens should be monitored from SCADA. 

Details of the fine screens are: 

Fine screens: 

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## 3.3.4.5 Grit and Grease Removal Tanks 

After the inlet pumping station or fine screen (as the case may be), the wastewater shall flow to combined aerated grit chambers and grease removal tanks. 

Aerated grit and grease removal tanks shall be designed, constructed and equipped regarding the requirements set in Table 2-1. The maximum flow (Q$_{WW;h}$) of the related stage requirements shall be met for the unit. 

The grit chamber and grease removal tanks shall be constructed as rectangular concrete structures. Length/Width ratio of the grit and grease removal unit (only grit section) shall be minimum 10. 

A diffuser system for the creation of coarse bubbles shall be mounted on the wall over the grit hoppers. The diffuser in grit chamber proposed by the Contractor shall be in accordance with the 

