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PAPER
HONG KONG URBAN COUNCIL
The following paper was laid on the table:-
(1) Report to the Urban Council by the Director of Urban Services and Secretary, Urban Council for the month of November, 1981.
QUESTIONS
1. MR. WALTER M. SULKE asked the following question (in English):—In view of the present water shortage, I believe that further investigations are necessary into the possible use of salt water for street cleaning. Is the U.S.D. aware that modern motor vehicles are built to withstand corrosion caused by the large scale use of salt in Northern latitudes to melt ice and snow and, accordingly, one should be able to expect such vehicles also to resist corrosion from salt water when this is sprayed on the road. Can we please be told what the objections are to using salt water for road cleaning. Are there any investigations being carried out how to overcome such objections?
DR. DENNY M. H. HUANG, CHAIRMAN OF THE ENVIRONMENTAL HYGIENE SELECT COMMITTEE, replied as follows (in Cantonese):---This question concerns the use of salt water for washing streets and is in two parts. The first part asks what the objections are to using salt water for road cleansing while the second part enquires whether any investigations are being carried out to overcome these objections.
The objections to using salt water for street cleansing fall into three main categories. Firstly, U.S.D. street washing vehicles, of which there are 57, are not designed to withstand the highly corrosive effects of salt water and Council would have to incur heavy expenditure to render the water tanks, pipes, pumps and body work corrosion-resistant.
The second category of objections concerns the effect which the salt water would have on roads and side-walk surfaces, metal structures such as lamp posts, parking meters, road signs, etc. and adjoining buildings. The Department recently used sea water for washing in a Sham Shui Po hawker area but this was discontinued following complaints that after washing there remained an objectionable fishy smell and that the salt water was corroding the metal framework of hawker stalls in the area. The salt water also had a detrimental effect on the paint marking the hawker permitted places which required much more frequent repainting than usual. It seems likely that it would have a similar effect on other road markings. In Sham Shui Po, the water was obtained from a sea water fire hydrant by departmental staff using buckets. No vehicles or other machinery were used in this instance.
The third category of objections concerns the effect that the salt and other residual substances might have on vehicles using the roads. The Department has consulted a number of organizations including the Electrical & Mechanical Office of the Public Works Department, the Hong Kong Automobile Association and the Consumer Council, and it seems that the majority of vehicles imported into Hong Kong are not protected against salt corrosion and that there is no legal requirement for such protective treatment. Although U.S.D. street washing operations concentrate mainly on the side-walks, surface channels and back lanes, it is inevitable that there is considerable spillage on to the main carriageways and that moving vehicles would pick up salt and other residual substances which would have a corrosive effect on them. It is also possible that the film of salt on the carriageway may make the surface more slippery for vehicles.
In the light of these objections, it would appear inappropriate to use salt water for street washing. During the current water restrictions, well water will continue to be used for this purpose.
(Miss Cecilia L. Y. YEUNG left at this point—4.12 p.m.)
MR. SULKE (in English):—Mr. Chairman, thank you for outlining the objections. But I don't think you have said whether the Urban Services Department will carry out research in order to overcome the objections?
DR. HUANG (in Cantonese):—Mr. Chairman, I believe that in the past, as I have mentioned in my reply, the Urban Services Department has consulted the Hong Kong Automobile Association, and the Consumer Council etc. and in Mr. SULKE's question, he pointed out that in colder countries overseas, they have to spread salt on the road because of the ice. However, in Hong Kong, we have never had ice and snow and it is certain we will meet with objections if we ask our vehicle importers to have protective measures for their vehicles. I believe the Urban Services Department had carried out the necessary investigations.
2. MR. WALTER M. SULKE asked the following question (in English):—I understand that the U.S.D. are thinking of computerizing the records of certain minor offences such as convictions for littering. Can we please have an assurance that such computerization records will be made and kept strictly within the Department in order to preserve confidentiality and that they will only be used to inform Magistrates of an offender's record?
DR. KIM Y. S. CHAM, CHAIRMAN OF THE ADMINISTRATION SELECT COMMITTEE, replied as follows (in English):-This question concerns the computerization of records of litter offences.
The Urban Council has always been concerned about frequent and repeated litter offenders in our efforts to keep Hong Kong clean. Because of manpower constraint and other requirements, it was not possible to maintain a manual record of litter offences with quick data retrieval and regular updating. It was
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HONG KONG URBAN COUNCIL