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(a) The estimated volume of marine sand dredged between 1992 and the end of 1995 is about 251 million cubic metres. The figures for 1991 are unavailable. This is approximately equivalent to the material available from 14 quarries each the size of the Anderson Road Quarry, scarring our visible hillsides. It is estimated that a total of 216 million cubic metres of marine sand will be required up to 2000. We plan to meet this future need by supply from Hong Kong and China.
The area of seabed that has been subjected to the impact of dredging and mud disposal, represents approximately less than 2.5% and 1.5% respectively of the total area of seabed within the borders of Hong Kong. All marine borrowing and disposal activities
activities are subject to environmental impact assessments and strict controls. Seabed surveys have established that apart from the limited areas directly involved, the seabed ecosystem is essentially unaffected. For the areas actually subjected to dredging, these are restored to original seabed level by controlled mud dumping. Recolonisation starts almost straight away, and the newly deposited seabed mud supports an early stage ecosystem after a few months.
(b)
In the past two years some 12 million cubic metres of marine fill materials were obtained by contractors from sources outside Hong Kong. On 7 July this year, Members approved funds for the commencement of the Fill Management Study phase VI. One of the key elements of this study will be to continue the investigation of potential fill sources outside Hong Kong, and available for import into Hong Kong. Contractors importing marine sand from China are subject to license conditions, as well as needing to enter into commercial arrangements, involving suppliers and the Chinese authorities. The cost will vary with transportation distance, site conditions, operational constraints and market price fluctuations. The fact that imported fill is being increasingly used by contractors demonstrates that cost can be comparable or perhaps lower than equivalent sourcing from Hong Kong.
(c)
Suitable construction waste and land based fill is used for our reclamations. For example the reclamations at Aldrich Bay and Tseung Kwan O in part are currently being formed using material deposited by controlled public dumping. 40% of the platform for the new airport at Chek Lap Kok was formed from marine sand, and the balance from land excavation.