HONG KONG URBAN COUNCIL
ADDRESS BY CHAIRMAN
CHAIRMAN (in English): It is just after 2.30 p.m. and I will call the meeting to order.
MINUTES
The minutes of the meeting held on 12th and 14th February, 1974, were confirmed.
PAPER
The following paper was laid on the table:
Reports to the Urban Council by the Director of Urban Services and Secretary, Urban Council, for the month of February, 1974.
QUESTIONS
(1) MR. LO TAK-SHING asked the following question (in English):— I understand from the Urban Services Department that the purpose of spraying emulsifiers on spilt oil is to enable the oil to form a scum and sink. The question that remains to be looked into is what happens to oil scum afterwards. For example, will it not, in due course of time, get washed ashore and stick to sand and rubble on our beaches?
MR. KENNETH T. C. Lo, CHAIRMAN OF THE RECREATION AND AMENITIES SELECT COMMITTEE, replied as follows (in English):-
Mr. Chairman, this question concerns the use of emulsifiers for dispersing spilled oil, and what happens to the oil scum formed after it has been treated by emulsifiers.
(Mr. C. K. CHAN arrived at this point.)
I understand that the department has made enquiries from the suppliers of the emulsifiers currently in use, and that it has been advised that at present there are no emulsifiers capable of completely destroying oil. Inevitably, therefore, part of the oil in any oil slick which has been treated and broken down by emulsifiers will be deposited on our beaches and around our coasts.
The emulsified oil, however, does not sink to the bottom and get rolled ashore, as Mr. T. S. Lo seems to suggest. The emulsifiers currently available in Hong Kong have the effect of dispersing the oil into minute particles which are held in suspension.
The department has also been advised that the destruction of oil after emulsification can only be done by a biological attack on the oil. However, this will take place much more rapidly when the oil has been treated and has been dispersed as minute particles. Apart from destruction by biological attack, the dispersal of oil which has been treated by emulsifiers is also much more readily effected by the action of winds and tides, with the result that much greater quantities of oil from an oil spillage can be carried out to the open sea. The remaining quantities that come inshore are dispersed over a much greater area of our coastline and our beaches where their effects are likely to be much less damaging than if the oil were to drift ashore undispersed and in concentrated form.
MR. LO TAK-SHING (in English):-Referring to the third paragraph of the answer, Mr. Chairman, where it was stated that the oil is held in suspension rather than sinking to the bottom of the sea, may I read a paragraph from a letter which I received from the Urban Services Department with regard to this, in direct contradiction of this, and perhaps ask a supplementary question as to why this is so? The relevant paragraph from the Urban Services Department letter says:
"Both the 'B.W. Conc' and 'B.F. 1002', the two types of emulsifier which we have been using for a number of years, are not in any way dangerous to health, and this has been confirmed from laboratory tests by the Government Chemist. The emulsifiers are applied for use in a diluted form, one part of the emulsifier to be mixed with five parts of water. The mixture will become more diluted when it is mixed with the water." This is the relevant sentence. "On contact with the oil scum will be formed and since it is heavier than water, it will sink to the bottom and disappear from the surface."
I wonder whether this letter is correct, or the answer is correct.
Page 200 of 212
328
HONG KONG URBAN COUNCIL
329
Page 200
Page 201