Earlier this month, more than 100 residents of Hong Mei House, a public housing block in Tsing Yi, were evacuated after members of several households in the building were tested positive for the coronavirus. Inspection found that the vent pipes had been disconnected in some of the flats, and alterations of the sewage pipelines were done without the Housing Department’s approval. It is suspected that the alterations of the pipework was a cause of transmission of the virus between flats. The Housing Department has warned residents that alterations done without the Department’s approval might fall foul of the Buildings Ordinance and tenancy requirement.
The scare has also prompted the Buildings Department to speed up the amendment of legislation in implementing new designs for the sewage systems in residential buildings, which will mandate separate waste pipes for upper and lower floors, as well as an improved U-shaped water pipe. Experts believe that with the current design, the pipes on lower floors could be put under great pressure, given the amount of solid waste accumulated from the upper-floor flats. It is believed that using separate pipes would minimise the chances of leakage in the lower-floor flats. Another amendment would be to regulate the design of floor drains to ensure the U-shaped water trap does not dry up.
Previously, following the 2003 SARS outbreak, the Buildings Department only released a practice note advising engineers to consider diverting some of the waste water from a waste fitment to the U-trap of floor drains in their designs to prevent it from drying up. Strictly speaking, the said practice note is of a general advisory nature or for the promotion of good practices in the building industry and is not legally binding or mandatory. Although the practice note does not have the force of law, we understand that any design contrary to it will not usually be approved by the Buildings Department. It is hoped that the new law will impose tighter regulations with improved designs of residential sewage systems and curb the spread of contagious disease.