LCQ 5: Demolition of incineration plant
Following is a question by the Hon CHOY So-yuk and an oral reply by the Secretary for Works, Mr Lee Shing-see, in the Legislative Council meeting today (February 27) :-
It has been reported that the Government plans to demolish the Kennedy Town Incineration Plant, which has ceased operation for years, in the middle of next year, and that the interior of the Plant is seriously contaminated with harmful substances. In this connection, will the Government inform this Council:
(a) of the ways in which it plans to dispose of the Plant's contaminated demolition waste; and
(b) whether it will formulate special procedures for the demolition of those components of the Plant which contain harmful substances such as dioxins or asbestos, in order to avoid posing health hazards to workers and nearby residents?
(a) The demolition of the Kennedy Town Incineration Plant is a designated project under the Environmental Impact Assessment Ordinance (EIAO), and as such an Environmental Impact Assessment has been carried out by Civil Engineering Department, the works department responsible for the future demolition of the plant and associated work. As part of this Assessment, the type and extent of contaminated materials that are within the buildings and the ground beneath, and how these will be dealt with, were broadly established.
The types of contaminated material found on site fall into four main categories, namely :
(i) Heavy Metal contaminated material,
(ii) Hydrocarbon contaminated material,
(iii) Asbestos containing material, and
(iv) Dioxin contaminated material.
Heavy Metal contaminated material has been found in the ground below the buildings. After demolition of the buildings, this material will be excavated, immobilised by mixing with cement and returned to the ground.
Hydrocarbon contaminated material has also been found in the ground below the buildings. After demolition of the buildings, this material will be treated by mixing with cement if necessary and disposed of in landfills.
Asbestos containing materials have been found in various locations in the buildings. The treatment of asbestos is well established in Hong Kong and will be carried out in accordance with the Code of Practice - "Safety and Health at Work with Asbestos".
Dioxin contaminated material has been mainly found in an area of rubble located at the seaward side of the incineration plant. This material will be immobilised and disposed of at designated areas in landfills. The immobilisation process will involve the mixing of the contaminated material with cement and placing the mixture in polythene lined steel drums. The drums will be fully sealed prior to disposal at designated locations in the landfills.
The treatment of the contaminated material is generally considered safe and consistent with international practice and has been determined by specialist consultants in consultation with the Environmental Protection Department. Moreover, the Civil Engineering Department will commence the detailed design of the demolition and decontamination works etc. in mid 2002. During the design stage, the demolition and decontamination process will be confirmed in detail.
As regards the EIAO process, the Environmental Impact Assessment Report has been made available for public inspection and Civil Engineering Department is responding to the comments received by EPD during the public inspection period. No demolition works will commence until the Director of Environmental Protection has approved the Report and issued an Environmental Permit for the works.
(b) As mentioned before, an Environmental Impact Assessment has been carried out for the project. The Assessment concluded that the works could be carried out without adversely affecting the health of the local residents.
Detailed demolition procedures will be worked out at the design stage of the project. In general, the demolition will be top down using manual tools and mechanical plant, with the reinforced concrete in the chimneys being cut into small pieces and carefully lowered to the ground through the inside of the chimney. It is expected that the contaminated materials in the building will be removed prior to demolition.
The main contaminant in the building is asbestos, and during its removal public safety will be assured by the use of full containment measures where the material is found to be friable, to prevent the release of asbestos fibres to the atmosphere. There was some dioxin contaminated material found adjacent to the incinerator building. Before handling, this material will be sprayed with a special wetting agent to suppress the release of dust to the atmosphere.
Workers will be protected from asbestos and dioxins by providing them with full body protective clothing and face masks. Training and close supervision will be provided and emergency plans will be developed. Also, the Commissioner for Labour will be consulted on all proposed safety measures relating to workers dealing with contaminated materials.
End/Wednesday, February 27, 2002