Trinidad & Tobago Water & Sewerage Authority, Trinidad

Hollis Water Treatment Plant; Capacity: 38 MLD Flow

The refurbishment of the Hollis Water Treatment Plant was awarded to UEM in May 2000. The major items included under the refurbishment were:

Refurbishment of the Pressure Filters. The refurbishment included changing of the filter under drain system. Filtering media new Backwash pump & Air Blowers and replacement of all the valves to electrically actuated valves.
Design and installation of an automatic chemical dosing system. It included the automatic adjustment of pump speeds using a variable frequency drive. The speed of the pumps varied based upon the plant output enabling a constant dosage of chemicals under variable flow conditions.
Design and installation of dirty backwash water sedimentation facility and sludge disposal system
Design and installation of new chlorine feeding system.
Design and installation of new electrical and controls. It included new transformer, HV switchgear, Generator, UPS & Motor Control Center. All the associated cabling and related work including the interlocking o various equipment's with PLC was also done.
Design and installation of complete plant automation including the PLC and the SCADA system.

The newly refurbished facility was commissioned in July 2001 and the complete system has been operating satisfactorily, producing 38 MLD of treated water meeting all the design parameters (turbidity, pH, color etc.)