HONG KONG URBAN COUNCIL
the lining passed its useful life, the trapped leachates will be released and pollute the surrounding environment. With the heavy rainfalls in Hong Kong, the effect of leaching can be rather serious. Furthermore, one should also take note of the fact that landfill sites, once used, are virtually wasted because subsidence of land formed from landfills renders them unsuitable for any development except for restricted passive landscaping.
Cost Comparison Between the Incineration and the Landfill Option
The main argument against using modern incinerator for municipal waste disposal is the high initial cost for installation. However, when analysing the cost of the two options over a period of 20 years, one may be surprised to find out that incineration works out to be the cheaper option even from the outset, taking into account the following factors:
(a) the depreciation of the initial installation cost of incinerators over a period of 20 years, as the normal life span of an incineration plant is longer than 20 years;
(b) the revenue produced by the sale of electricity generated by incinerators to electricity companies. It should be noted that for the same quantity of waste, heat and gas produced by incineration is five times more than that produced by landfills;
(c) the minimal space required for an incineration plant. A landfill site lasting 20 years requires 640 hectares of land whereas the site of an incineration plant with a life span of over 20 years only takes up 20,000 square metres of land, i.e. 0.8% of a landfill site;
(d) the requirement to install expensive equipment to collect poisonous gas and to prevent leaching in landfill sites. These equipments, once installed cannot be recovered or reused after the exhaustion of the landfill sites; and
(e) the value and scarcity of land in Hong Kong. In an overcrowded city like Hong Kong, landfill site is difficult to identify and will soon become exhausted.
Conclusion
In the disposal of domestic wastes, I must emphasize that both incineration and landfill have their respective roles to play. Landfill will be required for the final disposal of bottom ash after incineration. Throughout my years of study and research on this subject, I have gathered abundant scientific evidence and numerous practical examples throughout the world to support my assertion. Due to the limited time available on this occasion, I cannot present to all of you a comprehensive account of all my findings. Nonetheless, should anyone of you wish to discuss with me further, I will be most obliged to share with you my knowledge and experience.
I wish to take advantage of the opportunity of the Council's Annual Conventional Debate this year to reiterate my message and my plea to urge the Government to review its waste disposal policy and to consider introducing
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