Water supply system
The water supply systems of most buildings make integrated use of 3 types of systems, namely the direct supply system, indirect supply system and sump and pump supply system.
- Under the direct supply system, fresh water is transmitted directly from the public water mains to households at lower floors by means of hydraulic pressure inside the mains.
- Under the indirect supply system, a water pump is used to draw water from the storage tank installed at the ground level of the building, and fresh water drawn into the rooftop water tank is then transmitted to each household through a network of sub-mains.
- Under the sump and pump supply system, water is transmitted to the receiving end by fitting a pressure pump to the supply: a fire main is one that functions in this way.
- A water supply system comprises water pumps, risers, storage tanks, automatic float switches and sub-mains;
- All integral parts of the water supply system should be regularly checked and properly maintained.
- All water storage tanks should be cleansed at regular times for quality control.
- Drainage systems can be classified into the rain-water pipe system and sewage pipe system. The integral parts of a drainage system comprise the drain pipes, traps and manholes.
- Drain pipes should by no means be connected in an improper way, e.g. sewage discharged from sinks should not be emptied into any rain-water pipe.
- Drainage outlets should be clear of rubbish or fitted with gratings to prevent rubbish from blocking the pipes.
- All drain pipes, including soil pipes, waste pipes, ventilating pipes and underground drain pipes should be maintained in good working order without defects. All such pipes should be inspected regularly, and where leakage, blockage or defects are detected, they should be rectified immediately.
- In order to prevent putrid air and insects in the soil pipe from entering the premises, sanitary installations including hand basin, sinks, bathtubs and showers toilets and floor drains should be fitted with a trap (U-shaped water trap, bottle traps or anti-siphon traps). If the installation is not used regularly, pour about half a litre of water into each drain outlet once a week. Then, pour a teaspoon of 1:99 diluted household bleach solution into the drain outlet. For floor drains, spray insecticide into the drain outlets after cleansing.
- Manholes should be checked regularly and any blockage detected should be dealt with immediately.
- Manholes should be readily accessible for regular maintenance. Access to them should not be obstructed by floor finishes, planters or furniture items. Foul air leaking from manholes can be stopped by using double seal type manhole covers, or repairing the edges of the manhole openings or cracks in the manhole covers.
- Responsibilities for repair and maintenance of the drainage system is determined on whether the defective section of the pipe is for common use or for individual use. For example, if a rain-water pipe bursts, the owners' corporation or all owners shall be liable for repairing it. However, if a branch pipe connected to an individual flat is damaged, the owner or occupant of that flat shall be responsible for repairing it.
For further details in water supply and drainage system, please call hotline 043 773 8686 to be consulted by PMC.
Guidelines on Maintenance and Repair of Drainage System and Sanitary Fitments and Notification of Completion of Inspection on Drainage Works