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BD reminds public on requirements for alteration of drainage systems and their proper maintenance

BD reminds public on requirements for alteration of drainage systems and their proper maintenance

In view of recent public concern about the repair, maintenance and alteration of the drainage system of domestic flats, a spokesman for the Buildings Department (BD) gave the following remarks today (February 12):

(1) Building owners who wish to erect, alter or remove the drainage system (including the anti-syphonage pipes) in their premises may so pursue in accordance with the simplified requirements under the Minor Works Control System by appointing suitable contractors registered under the Buildings Ordinance so as to ensure that the drainage system in their premises are in compliance with the provisions of the Buildings Ordinance and the relevant regulations. These include every sanitary fitment (such as water closet, wash basin and bathtub) should be provided with an effective water seal (such as a trap with anti-syphonage provision). Such requirements are also applicable to the erection or alteration of drain pipes involved in subdivision of flats.

(2) The contractors registered under the Buildings Ordinance for such kind of works shall satisfy the requirements of the BD on qualifications, competency and experience. Any person other than a qualified registered contractor or a person acting under the supervision of a qualified registered contractor, who, without reasonable excuse, certifies or carries out minor works shall be guilty of an offence. Furthermore, the BD has reminded registered contractors the requirements on drainage works in the Technical Guidelines on Minor Works Control System. The registered contractors shall comply with the relevant statutory and safety requirements when carrying out, supervising the works and certifying completion of works. They shall also submit the completion certificates and relevant information to the BD.

(3) To ensure the quality of works, the BD will randomly select completed works for checking, which includes checking of submitted documents and site audit as necessary. The audit check system is risk-based, focusing on minor works items that are more complicated and involving a higher level of risk. The BD will increase site audit on minor works involving alteration of drainage systems in building units in order to enhance the monitoring of such kind of minor works.

(4) If contravention of the provisions of the Buildings Ordinance is found during the audit check, the BD will take enforcement action including requiring the concerned persons to rectify and instigating prosecution and disciplinary actions against the concerned persons as necessary.

(5) If occupants suspect irregularities in the drainage system of their premises, such as odour from the drainage outlet or anti-syphonage pipe, seepage or cracks at the drainage pipes, they should arrange qualified contractors to conduct checking and repair as soon as possible. The BD has formulated a set of guidelines reminding the public on the proper maintenance and repair of drainage pipes including traps, which is available on the department's website ( The BD will continue its work on stepping up public education and publicity to enhance people's understanding about the drainage system and its proper repair and maintenance.

Ends/Wednesday, February 12, 2020