MECHANICAL REFURBISHMENT

This project involved the complete mechanical refurbishment and upgrade of the existing 30Ml/d plant No 1 at Vaalkop Water Purification Works to cope with deteriorating raw water quality. The flow into the plant is a blended combination of raw water from Vaalkop Dam and supernatant water generated from the backwash and de-sludging operations.

The new process stream involves pre-ozonation, flocculation, dissolved air floatation, inter-ozonation (2 stages), sand filtration, GAC filtration, disinfection and chemical dosing (Ferric chloride, polymer, lime and chlorination).

As part of the project PCI supplied:

• One new raw water pump valves and pipework, capable of delivering 1314 m3/hr at 26m head
• Twelve new filter floors and underdrain systems complete with all filter pipework and electric actuators (Seven Sand and Five GAC filters).
• Complete chemical dosing system comprising of Ferric Chloride (primary and secondary), polyelectolyte (primary and secondary).
• Dry lime system comprising of a 40 M3 silo, 2 x 1M3 daybins, complete transfer system and feeder system
• Two new Archimedes screw pumps preceding the rapid gravity sand filters
• Two new Archimedes screw pumps preceding the GAC filters
• Complete chlorine system including an emergency drum shut-off system
• Backwash and air blower pump station including all pipework and valves.
• Complete DAF system comprising of recirculation pumps, compressors, saturator vessel and all distribution pipework for 4 x tanks.
• Transfer pumpstation comprising of 2 x axial flow pumps capable of a transfer rate of 1250 m3/hr at 8.1M head.