Mit Fares

The contract for the mechanical and electrical works associated with the new water treatment works at Mit Fares (located within the Nile Delta in Egypt) was awarded by NOPWASD in January 1995. The ?1.9 million contract for phase 1 - to achieve a treated water output capacity of 34,500 cubic metres per day - was completed and commissioned in April 1996.

Raw Water Intake
Raw water is drawn by gravity from the canal into a raw water sump, then pumped some 2.5 kilometres to the raw water distribution shaft at the treatment works. Four horizontal, split case centrifugal raw water pumps were installed, each capable of delivering 220 litres per second and driven by 75 kW motors.

Mixing, Flocculation, and Sedimentation
Chemically dosed raw water is distributed into two streams for flash mixing, hydraulic baffle flocculation and sedimentation. The rectangular horizontal flow sedimentation tanks are equipped with reciprocating automatic scraper mechanisms for sludge removal.

Sand Filtration
The six rapid gravity sand filters are designed for semi-automatic operation from individual control consoles. Filter washwater pumps, air blowers and air compressors were installed in the machinery room.

Sludge Disposal
Settled sludge from sedimentation tanks and dirty filter washwater, flows by gravity to two sludge holding tanks from where it is pumped to the disposal point. Three centrifugal solids handling pumps were installed, shaft driven by 99 kW motors, each pump capable of delivering 250 litres per second.

Standby Power Generation
Standby electrical power at 11000 volts is provided by two 1000kVA diesel driven generating sets with synchronisation equipment to enable parallel operation.

Plant Monitoring Panels
Main electrical functions and process operations are monitored and displayed on separate electrical and process mimic panels. Panel indication includes medium and low voltage circuit breaker operation and pump status.

Main flows, pressures and levels are displayed on local monitoring panels from field mounted transmitters. Signals are transmitted to the control room for display on the main plant monitoring panel.

Chemical Dosing
Gaseous Chlorine dosing equipment was provided for pre and post treatment disinfection with gas leak detection and caustic soda neutralisation tower to deal with any major gas leakage. Chemical handling, solution preparation equipment and precision dosing pumps were provided for the addition of coagulant (alum) to the raw water.

Electrical System
The electrical system installed provides power for the drive motors, valve actuators, instrumentation, controls and general site utilities. The system includes a 11 kV vacuum motor operated incoming circuit breakers with medium and low voltage switchgear panels for distribution networks of 11 kV, 3.3 kV and 380/220 volts.

Treated Water Pumping
Treated water flows by gravity from the underground reservoir to the treated water sump and is them pumped into the potable water distribution system. Four horizontal, split case centrifugal treated water pumps were installed, each capable of delivering 200 litres per second and driven by 175kW 3300V slip ring motors. Surge protection equipment and a vacuum priming system were also provided.