Following is a question by the Hon Wong Sing-chi and a reply by the Secretary for Housing, Planning and Lands, Mr Michael Suen, in the Legislative Council today (May 7):
Question:
According to the "Main Findings of an Investigation into the Outbreak of Severe Acute Respiratory Syndrome ("SARS") at Amoy Gardens" released by the Department of Health, each block of Amoy Gardens has eight vertical soil stacks for collecting effluent from the same numbered units on all floors. The soil stack is connected to the water closets, the basins, the bathtubs and the bathroom floor drains. Recent studies have shown that coronavirus exists in the stools of many patients with SARS, where it can survive for longer periods than on ordinary surfaces. Furthermore, it has been reported that soil stacks in old buildings are made of iron pipes, where bacteria can breed easily. In this connection, will the Government inform this Council whether:
(a) it has statistics on the number of residential buildings in Hong Kong with soil stacks design similar to that in Amoy Gardens; if it has, of the percentage of such buildings in all residential buildings in the territory;
(b) it has considered amending the legislation to require separate discharge of effluent and stools in the future design of soil stacks for residential buildings, in order to reduce the spreading of bacteria and viruses; if it has, of the timetable for amending the legislation; if not, the reasons for that; and
(c) it has considered asking owners or owners' corporations of old buildings to replace soil stacks made of iron pipes; if it has, of the timetable for the replacement; if not, the reasons for that?
Reply:
President,
The deduction of the Government's investigation is that the outbreak of Severe Acute Respiratory Syndrome at Block E, Amoy Gardens was the result of a combination of possible factors. It was not triggered by any one single factor, such as a defective drainage system.
Under the Buildings Ordinance, both "two-pipe" and "one-pipe" designs are acceptable drainage system designs. The former allows foul and waste water to be disposed through separate pipes, while the latter discharges all effluent through the same pipe. There should be no pollution of the living environment or sanitary nuisance prevented as long as a drainage system, whether of "one-pipe" or "two-pipe" design, has been installed in compliance with the standards specified by the Buildings Ordinance and is kept in good maintenance and repair. Similarly, no pollution would result whether the pipes are UPVC pipes or cast iron pipes, if they are properly installed and maintained.
The replies to the three parts of the question are as follows.
(a) The drainage system in Amoy Gardens adopts the "one-pipe" design. Since both the "one-pipe" and "two-pipe" designs are in line with the requirements of the Buildings Ordinance, we do not keep separate statistics for each of them. Therefore, we do not have the number or percentage of buildings categorised according to the drainage system design.
(b) As I have pointed out above, there should be no pollution of the living environment or sanitary nuisance as long as drainage systems, whether of the "one-pipe" or "two-pipe" design, are installed according to the requirements of the Buildings Ordinance and are properly maintained and repaired. Therefore, our foremost task is to abide by the relevant legislation and to ensure timely and proper maintenance of the drainage systems. At present, it is not necessary to amend the legislation solely because of the current concern.
The use of cast iron pipes is in order if it meets the requirements of the Buildings Ordinance and is up to the relevant standards of design and installation. If properly maintained, cast iron pipes can normally last for 15 years or more. Provided that the pipes comply with the stipulated standards, it is difficult to generalize the need and time for their replacement, whatever materials they are made of. Much depends on their actual conditions. Therefore, there is no need for the Government to stipulate a fixed timetable for the compulsory replacement of pipes.
End/Wednesday, May 7, 2003
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