Water Installations

Comprehensive rehabilitation of twenty-eight water installations, capacities ranging from 100 m³/hr to 6,500 m³/hr

A typical comprehensive rehabilitation of a water installation would include work on all sections of the installation from the intake to the outlet.

Work would include the replacement of dysfunctional or broken equipment, overhaul and maintenance of equipment that could be brought up to operational level, installation of new equipment and the consequent installation of new piping and electrical cabling.

Upon completion of rehabilitation, the facility would be operational at 80% of its design capacity.

These group of former CARE staff were responsible for the initial assessment of the plants, identifying and placing orders for the equipment to be procured with international companies, drawing up bills of quantities both for equipment and work, liaising with Government Authorities and overseeing the work.

Below is a brief description of the type of work undertaken on each section of the installation during a comprehensive rehabilitation

Intake

Repair of the intake structure or its replacement if in an extremely poor condition.

Where the level of the water has receded, the intake structure was extended to an optimum position to obtain a good raw water supply. Suction pipes and foot-valves were repaired if that was possible, while in some cases they had to be replaced.

If instead of an intake there was a suction well, this would be thoroughly cleaned and maintained and where it was beyond repair, a new suction well was constructed using reinforced concrete. As part of the repair or construction of an intake structure, all pulleys, cranes and walkways were either overhauled or replaced as necessary.

Low lift section

• Low lift pumps of capacities ranging from 50 m³/hr to 1,450 m³/hr were either overhauled or replaced.
• Suction gate valves, delivery gate valves and non-return valves as well as electrical actuators for valves were overhauled or replaced.
• Piping systems for suction and delivery pipes were overhauled or the system redesigned to fit the new pumps.
• Submersible pumps (de-watering) were installed to ensure that the pump house was kept fairly dry.
• Cables were either re-arranged or replaced on cable trays above the water level in the cable channels.
• Ceramic tiles were fixed to the walls of the pump house.
• The main electric board was either overhauled or replaced depending on the condition.
• The pump house gantry crane was overhauled and operated.

High lift pumps

• Overhaul or replacement of pumps, motors, starters.
• Overhaul or replacement of suction gate valves, non-return valves, delivery gate valves and valves for electrical actuators.
• Re-arrangement of feeding points and replacement where necessary to install new pumps.
• Submersible pumps for de watering.
• Re-arrangement or replacement of electric cables and support trays.
• Overhaul or replacement of main electric board.
• Re-arrangement of cable channels and channel covers.

Clarifier section

• Concrete and metal clarifier tanks of capacities ranging from 50 m³/hr to 900 m³/hr were cleaned and overhauled. Where metal tanks were beyond repair, a concrete clarifier was constructed to replace it.
• Scraper structures, bridges and drive sets were overhauled or replaced.
• Flash mixers were overhauled or replaced.
• Flocculators were overhauled or replaced.
• Pipes in metal tanks were replaced.
• Valves and penstocks for raw water, clarified water and sludge disposal were overhauled or replaced.
• Sludge disposal process was made operational.
• Embankments supporting concrete tanks were reinforced.