LC Paper No. CB(1)1703/98-99
(These minutes have been
seen by the Administration)
LegCo Panels on Environmental Affairs and
Members of the LegCo Panel on Environmental Affairs
Planning, Lands & Works
Minutes of joint meeting held on
Tuesday, 4 May 1999, at 2:30 pm
in Conference Room A of the Legislative Council Building
Members present :
Hon Christine LOH (Chairman)
Hon HUI Cheung-ching (Deputy Chairman)
*Dr Hon Raymond HO Chung-tai, JP
Hon CHAN Wing-chan
Hon YEUNG Yiu-chung
Hon LAW Chi-kwong, JP
Members absent :
Prof Hon NG Ching-fai
Hon Bernard CHAN
Dr Hon LEONG Che-hung, JP
Hon Mrs Sophie LEUNG LAU Yau-fun, JP
*Hon WONG Yung-kan
*Hon LAU Kong-wah
Hon Mrs Miriam LAU Kin-yee, JP
Hon CHOY So-yuk
Members of the LegCo Panel on Planning, Lands & Works
Members present :
Hon Edward HO Sing-tin, JP (Chairman)
Dr Hon TANG Siu-tong, JP (Deputy Chairman)
Hon Ronald ARCULLI, JP
Hon James TO Kun-sun
Hon TAM Yiu-chung, JP
Members absent :
Hon HO Sai-chu, JP
Hon LEE Wing-tat
Hon LAU Wong-fat, GBS, JP
Hon Andrew CHENG Kar-foo
* also a member of the LegCo Panel on Planning, Lands and Works
Public officers attending:
Clerk in attendance :
- Mr Kim SALKELD
- Deputy Secretary for Planning,
Environment and Lands (Environment)
- Mr CHAN Wing-sang, JP
- Deputy Secretary for Works (Works Policy)
- Mr John COLLIER
- Director of Drainage Services
- Mr Raymond CHEUNG
- Assistant Director of Drainage Services
- Mr C K HON
- Chief Engineer/SSDS
Drainage Services Department
- Mr KWONG Hing-ip
- Chief Assistant Secretary for Works
Staff in attendance :
- Miss Odelia LEUNG,
- Chief Assistant Secretary (1)1
I Election of Chairman
- Mrs Mary TANG,
- Senior Assistant Secretary (1)2
Miss Christine LOH was elected Chairman for the joint meeting.
II Strategic Sewage Disposal Scheme Stage I : Construction supervision of the main works
(LC Paper No. CB(1)1211/98-99(01) and (02))
2. At the invitation of the Chairman, the Director of Drainage Services (DDS) reported the progress of the Strategic Sewage Disposal Scheme (SSDS) Stage I tunnelling works which was set out in LC Paper No. CB(1)1211/98-99(02). He advised that as at April 1999, 33% of the tunnelling works had been completed and the contractors had gone through the learning curve and had been progressing at the rate of 350 to 450 metres per week across the five tunnels. He was hopeful that the present rock condition would prevail and that the works progress could be maintained. Although further technical problems might be encountered, as the contractors had done very well in dealing with technical problems so far and had better methodology and equipment, the Administration was confident that all tunnels could be completed before the end of the year 2000. DDS informed that three LegCo members had visited the tunnelling site and observed the tunnelling works in progress. With the aid of video, he explained the operation of tunnel excavation works on site for the benefit of those members who had not visited the site.
3. DDS then explained the background and justification for the funding request for increasing the approved project estimate for item 312 DS for construction supervision of some of the main works for Stage I of SSDS (LC Paper No. CB(1)1211/98-99(01)). DDS said that the main reason for the increase was the unanticipated delay in completion of the works which required the retention of site supervisory staff for a longer period. An additional $98.8 million was thus needed to fund the necessary supervisory work. He informed members that the funding proposal would be submitted to the Public Works Subcommittee at its meeting on 12 May 1999.
4. Mr HUI Cheung-ching was concerned about the revised estimate of the resident site staff costs which was increased by 160% from the approved estimate. The Chief Engineer/SSDS, Drainage Services Department referred members to enclosure 4 to the paper which provided a breakdown of estimates of consultants' fees. He explained that in early 1998, the total number of professional and technical resident site staff was roughly about 100. As shown in enclosure 2 to the paper, the completion dates of most contracts were deferred from early 1998 to mid 1999. The delay was roughly about 15 months. The revised estimate of resident site staff cost was based on the estimated man-months which were derived by multiplying the respective numbers of professional and technical site staff with 15, i.e. 35 persons X 15 and 75 persons X 15 respectively. The Assistant Director of Drainage Services (Sewage Services) (AD/DS) added that the proposed net increase of $98.8 million represented an increase of 16% over the original approved project estimate of $610 million.
5. As regards Dr TANG Siu-tong's enquiry on the progress of arbitration of claims for losses arising from the re-entry of the two tunnel contracts, DDS advised that the arbitration process was going on and the arbitrator had set a date in early 2000 for the main hearing to commence. Three preliminary hearings had been held and it was expected that a decision could be reached by end 2000. DDS pointed out that this was the first time in the history of Hong Kong that the Government had to call for the forfeiture of contracts as a result of the cessation of works by contractors. It was believed that the SAR Government would have a good case against the contractors.
6. Responding to Dr Raymond HO's enquiry about the comparative difficulties of the different stages of SSDS, DDS said that the experience gained in the implementation of Stage I would be used in the preparation of estimates on time and cost for the subsequent stages of SSDS. Members would have a chance to debate these issues when funding was sought from LegCo, which would be expected to be around $8.5 billion for Stages III and IV. With the experience gained in tunnelling works and the state-of-the-art technology, the Administration could now comment more meaningfully on the design proposals and contract proposals for subsequent stages of SSDS.
7. The Chairman sought confirmation as to whether the interim outfall tunnel, which was 1.7 kilometres in length and 5 metres in diameter, was completed to full specification. DDS confirmed that the interim outfall tunnel was completed in accordance with the original specification. There were some adjustments made in the prevention of water ingress but according to the Engineer, this had not materially affected the quality of the finished product.
8. Responding to the Chairman's further enquiry about the water ingress problem, DDS informed that the water ingress happened during construction of the segmental lined tunnel. After the excavation works had been completed and the segments had been lined, the contractor had to go back and grout to a fine tolerance. The only reason to have that tolerance was to guarantee quality, not to prevent leakage as when the tunnel system was in operation, it would be under full head of sewage anyway.
9. In response to the Chairman's request for a breakdown on the progress of works for each of the tunnels, DDS provided the following information based on the progress as of 2 May 1999 -
|Tunnel ||Total Length|
|Tunnel length |
|-||Tunnel G from Kwai Chung to Tsing Yi||-||-||completed
|-||Tunnel F from Tsing Yi to Stonecutters Island||3,580||1,634.6||45.7%
|-||Tunnel E from To Kwa Wan to Stonecutters Island||5,495||1,405||25.6%
|-||Tunnel D from Kwun Tong to To Kwa Wan||3,572||1,576||44%
|-||Tunnel C from Tseung Kwan O to Kwun Tong||5,332||2,145||40%
|-||Tunnel AB from Chai Wan to Kwun Tong||4,380||971||20%
10. Mr HUI Cheung-ching doubted whether the Administration could complete the project by the year 2000, given that most of the tunnels were not yet half completed. AD/DS said that for Tunnel AB from Chai Wan to Kwun Tong which was the least completed, the contractor had gone through the initial learning curve and the progress rate had picked up. Tunnel F from Tsing Yi to Stonecutters Island which had the most difficult ground conditions had been 45.7% completed. The progress of works would depend on the variations in ground conditions. The Administration was hopeful that the project could be completed in the year 2000 although it could not be sure about the exact date of completion. The Administration was mindful of the need to complete the project expeditiously but it would not compromise on safety.
11. On the Chairman's concern about the problems associated with the construction of Tunnel AB, DDS said that the contractor was slower than anticipated in mobilizing because he was trying to get the best equipment in place to make good progress. Now that the new equipment was in place, the Administration believed that the contractor could excavate an average of 150 metres per week within a month or so. The contractor responsible for Tunnel AB and Tunnel C had to work on two tunnels at the same time. Priority was given to Tunnel C which was the longest tunnel. The problems with ground conditions in Tunnel AB could be readily dealt with by the equipment which had been installed.
12. As regards the Chairman's concern about rumours of subsidence in Tunnel AB, DDS explained that extra care was taken in excavating under sensitive areas with respect to the inflow of water into the tunnel. Whilst the contractor was excavating under the Typhoon Shelter which was a non-sensitive area, there was considerable water ingress which caused settlement of seawalls. The settlement had subsided after some ground treatment. The contractor was now working in sensitive areas and proceeding with excavation works in line with specification.
13. AD/DS added that subsidence caused by ground water drawdown could happen at any tunnelling stage. When this happened, grouting and water control works had to be performed and the progress of excavation would inevitably be slowed down. The contractor had just completed the mobilization of the tunnel boring machine works when the water ingress problem emerged. As a result, the excavation works were slowed down. It was expected that in a month or so, the progress rate could pick up and the excavation works could proceed in accordance with the programme. AD/DS said that as was the case for Tunnel C from Tseung Kwan O to Kwun Tong, after the contractor had gone through the initial stage, progress rate had picked up. The contractor had a record of excavating nearly 200 metres per week. He was therefore confident that the progress of works in Tunnel AB could pick up after the water ingress problem was resolved.
14. The Chairman sought information on the extent of technical problems that could be foreseen from geotechnical surveys. DDS referred members to Tunnel F which had to go across Tolo Fault between Tsing Yi and Stonecutters Island. He said that this fault was a difficult feature. Long coring was being performed by drilling a hole along the intended line of drive so that the contractor would know in advance the geological conditions which had to be dealt with and the appropriate methodology that should be applied. This was an example of how a risk could be dealt with. DDS assured that in any case, a contingency plan was in place to deal with emergency problems.
II Any other business
15. There being no other business, the meeting ended at 3:15 pm.
Legislative Council Secretariat
15 July 1999