Advisory Council on the Environment

Agenda Item 1 : Confirmation of Minutes of the 66th and 67th Meetings

Noting that the draft minutes were only circulated to Members on that day, the Chairman suggested and Members agreed to defer the confirmation to the next meeting.

Agenda Item 2 : Matters Arising

2. There were no matters arising from the last meeting.

Agenda Item 3 : Decommissioning of Cheoy Lee Shipyard at Penny's Bay
(ACE-EIA Paper 5/2002)

3. A Member declared interest as the Hong Kong Productivity Council (HKPC) had agreed to provide technical support to a company which might take part in the decontamination exercise but he said that no advice had been given to that company yet. The Chairman ruled that that Member could take part in the discussion but should abstain from voting if voting was necessary.

Internal discussion

4. A Member commented that in-situ capping of the dioxin-contaminated soil was undesirable because the long-term environmental risk would remain on site and affect the future land use. His next concern would be whether all possible alternative treatment methods had been explored and whether the proposed one was environmentally acceptable with the lowest risk. Another Member echoed that Member's views and said that after a research on the internet, he agreed that in-situ capping was not preferable.

5. In response to the Chairman's question regarding the base catalyzed dechlorination (BCD) technology, a Member said that he only quoted BCD as an example. The key concern was whether the project proponent had compared the pros and cons of different methods before coming up with the proposal.

6. A Member said that the proponent should clearly set out the comparison on alternative treatment methods in terms of destruction efficiency and different level of concentration of dioxin. Apart from that, the project proponent should also demonstrate the risks of on-site and off-site remediation and present a full comparison of the cost-effectiveness of different methods, both on-site and off-site, including direct incineration at the Chemical Waste Treatment Centre (CWTC) at Tsing Yi.

7. In response to that Member's last remark, a Member said that the project proponent had presented a table on the cost effectiveness of incinerating dioxin-contaminated soil at CWTC. The question was whether the figures were accurate and reliable.

8. The Chairman said that a Member also raised queries on the basis of calculation of those figures. He would ask the project proponent to address the concern.

9. The Chairman asked Members whether they were satisfied with the project proponent's response regarding the rice fish. In response, A Member said that although the project proponent could not ascertain the cause of disappearance of the rice fish, they had proposed in the EIA report to re-create the habitat and introduce the fish to the new habitat. Another Member suggested extending the monitoring period on the re-created habitat to more than one year. The Chairman said that the proposal could be included as a condition if Members agreed to endorse the report.

10. A Member would like to know whether the project proponent had past records of the inventory and activities at the site so that instead of relying solely on soil surveys, there would be reliable estimates on the contaminants in the soil.

11. A Member informed Members that at the meeting of the LegCo Panel on Environmental Affairs (LegCo EA Panel), Council Members doubted whether the project proponent suggested only one dioxin decontamination method because of the time constraint of the project.

12. The Chairman reminded Members that the discussion and consideration should base on environmental grounds. Factors like time and cost requirements were outside the remit of the ACE.[The project proponent team was invited to join the meeting at this juncture.]

13. The Chairman welcomed Dr. C K Lau et. al. to the meeting. He informed Dr. Lau that the Subcommittee was satisfied that in-situ capping was not a desirable option for treating dioxin-contaminated soil. The remaining concerns were (a) how the proposed option, i.e. thermal desorption plus incineration, was compared with other technologies, e.g. thermal desorption plus BCD, and (b) whether To Kau Wan was the best site for the thermal desorption plant.

Presentation

14. Dr. Lau then briefed Members on the nature and magnitude of the dioxin problem at the shipyard. In response to the Chairman's question, Dr. Lau explained that the overall average dioxin concentration in all soil samples in CLS was 1.6 ppb. In some localized spots like those in the burn pits, the average dioxin concentration in all samples greater than 1 ppb was 9.7 ppb, about nine times higher than the clean up standard of 1 ppb (same as United States Environmental Protection Agency (USEPA) clean up standard for residential soil). The maximum dioxin concentration found was 109 ppb. Dr. Lau informed Members that the EIA had evaluated six alternatives for cleaning up the dioxin contaminated soil, namely in-situ capping, direct incineration, thermal desorption plus residue treatment, solidification, vitrification and bioremediation. He explained the first option and Mr. Ko gave a comparison on the remaining options.

15. Mr. Ko compared the use of BCD and incineration in treating the dioxin condensate generated from the thermal desorption process. He said that the destruction efficiency of BCD was much lower than incineration. Furthermore, there was no BCD plant in Hong Kong. It would be necessary to build a new BCD plant if that option was selected. In addition, BCD would generate five times more residues in the form of oily waste. Since there was no licensed oil recycler in Hong Kong to handle such waste, it would eventually be incinerated. Mr. Roy Patterson supplemented that according to USEPA, there were limited proven track records of the application of BCD. Though there were a number of completed pilot programmes, the technology was still considered an emerging and innovative technology under development. Apart from the licensing and plant construction issues, the treatability test which determined the operating parameters and the effectiveness of the method was also a concern. In order to obtain residues for the test, it was necessary to set up a thermal desorption plant to produce sufficiently large samples of dioxin condensate. Taking into account the above, it was neither practical nor cost-effective to adopt BCD for treating dioxin condensate. By contrast, incineration was identified by USEPA as the best demonstrated available technology

16. Mr. Ko informed Members that the cost of the different options were estimated as $100M for in-situ capping; $425M for direct incineration at a new incinerator; $610M for incineration at CWTC with major modification; $350M for thermal desorption plus incineration at CWTC; and $420M for thermal desorption plus BCD plus incineration.

17. Mr. Eric Ma explained that if thermal desorption was conducted on-site, the site preparation work, the setting up of the treatment plant, the thermal desorption process and the eventual decommissioning would take three to four years' time. It would have a series of knock-on effects on other infrastructure works and would delay the Theme Park project. He then briefed Members on the comparison between four potential sites for the thermal desorption plant, namely Penny's Bay Area 6B, Tai Chuen, Siu Ho Wan and To Kau Wan. The areas of the first two sites were inadequate for constructing the plant and Siu Ho Wan was reserved for another project.

18. Mr. Ko explained that the contaminated soil had low inherent risk because dioxin was non-volatile, non-flammable, insoluble in water and the level of concentration was low. The dioxin condensate also had low inherent risk because it was non-volatile, not soluble in water and of low flammability. The risk of spillage or explosion of the materials was negligible. Regarding the safety measures for transporting the contaminated soil, a licensed waste collection fleet would be in charge of the work, the roll-off trucks with sealable top would be under speed limit control and the escort of two other vehicles. The route from the shipyard to TKW would not trespass any public express roads or highways. Regarding the thermal desorption process, the operation and the monitoring of the process would be computerized and automatic feed cut off was programmed in case of emergency. The processed soil would be subject to confirmatory testing everyday until it was certified clean.

Direct incineration at CWTC

19. The Chairman invited the project proponent team to respond to a Member's queries on figures concerning the time and cost required in adopting direct incineration at CWTC. In response, Mr. Mike Pang said that the main component of the cost presented in the table was the operation cost calculated according to the chemical waste treatment charge specified under the Waste Disposal Ordinance. As regards the capital cost for modification, it was an estimate based on previous modification works.

20. The Chairman said that that Member reckoned that the volume of flue gas generated by wastes was the dominating factor that determined the capacity of an incineration system. Mr. Mike Pang disagreed with that Member's point and said that the determining factor was the volume of soil, not gas.

21. Mr. Ko informed the meeting that compared with thermal desorption, heating the soil up to 1,200 oC in the incinerator would produce more green house gas. Moreover, direct heating would have a high chance of generating secondary dioxin. Therefore, thermal desorption was considered a better option on environmental grounds. Mr. Patterson supplemented that the throughput rate of incineration was lower than thermal desorption, thereby extending the process time.

The use of incineration or BCD for residue treatment

22. A Member said that it was not possible to get into technical details of various treatment technologies in such a short meeting. His concern was thus whether the project proponent had exhausted all viable technologies and weighted the environmental benefits of each of them before coming up with the current proposal.

23. In response, Mr. Dickson Lo assured Members that they had gone through a rigorous exercise of comparing alternative treatment technologies and recommended the most environmentally friendly option. Mr. Patterson said that the Independent Environmental Consultants (IEC) engaged by the Hongkong International Theme Park Ltd had conducted a parallel but independent evaluation of not only the site characterization data but also remedial alternatives available to address the contaminants found on site. It was the IEC's view that the remedial measures recommended in the EIA report submitted by Maunsell was appropriate.

24. A Member asked about the concentration of dioxin in the final output of the treatment process and whether the standard was up to a safety level in the local context. In response, Mr. Ko explained that the condensate would contain 1ppm dioxin and the incinerated ash must meet the 1ppb level before solidification and disposed of in landfill. The emission from incineration would be subject to 0.1 ng/m3. The levels were based on the standards adopted in the United States and 1ppb was considered clean standard for public filling.

25. A Member asked why the residue after the BCD process was not considered clean even when it was below 1 ppb level. In reply, Mr. Ko said that the residue from BCD was not solid but waste oil which could either be recycled by licensed operator or incinerated. In response to the Chairman's question, Mr. Ko said that in the Australian case, the waste oil generated by BCD process was recycled.

26. In response to a Member's enquiry, Mr. Ko said that the recycled oil was used as heating oil.

27. A Member said that on-site incineration might delay the opening of the Theme Park but on the other hand could save the cost for transporting the contaminated soil from the shipyard to To Kau Wan, and hence minimize the future land cost of the site. The Chairman said that land cost was outside the remit of the Subcommittee but nevertheless the Administration should note that Member's comment.

28. The Chairman asked Members if they agreed that thermal desorption plus incineration was an acceptable option. A Member had reservation in accepting the additional information provided by the project proponent during the presentation as part of the EIA submission. She considered that the results of the treatability test on thermal desorption and BCD should be made available before deciding on any option.

29. In response to that Member's comments, Mr. Ma said that all the information in the presentation was extracted from the EIA report except for the cost comparison of direct incineration at CWTC which was prepared upon request of the Subcommittee. As regards the treatability test on thermal desorption, samples of contaminated soil were sent to the United States for testing and the results would be due in two months' time. He emphasized that the viability and the effectiveness of the thermal desorption process was certain. The purpose of the test was only to identify the operating parameters of the plant for the particular soil in question. Regarding the treatability test on BCD, Mr. Ko reiterated that large quantity of soil would need to be sent to the United States for thermal desorption to obtain the condensate for further testing.

30. A Member was of the opinion that the project proponent should be aware of the history or inventory of the contamination of the site because it might involve a matter of legal liability. The Chairman said that legal liability was not a concern of the Subcommittee.

31. In response to a Member's question, Mr. Patterson said that the dioxin found on site was formed from burning wastes in the burn pits.

Site selection

32. A Member enquired about the measures that would be taken to ensure that the To Kau Wan site was properly cleaned up after the decommissioning of the thermal desorption plant. In reply, Mr. Ko said that the whole site would be covered by concrete to prevent contaminants from leaching into the soil. A proper drainage system would be put in place to direct rainwater or operation run-off to waste water treatment plant for proper treatment and disposal. After decommissioning the plant, soil samples would be taken to ensure that the site was properly cleaned up.

33. In response to the Chairman's question, Dr. Lau said that soil samples would be taken before the construction of the plant to form the baseline data for comparison with soil samples taken after decommissioning.

34. A Member expressed concern that the risk of dispersion of dioxin was high at To Kau Wan due to its coastal environment and its close proximity to a highway. She was also concerned that in case of delay of the decommissioning of the plant, there would be risk of cross contamination of the soil stored in drums waiting to be transferred.

35. In response to that Member's concerns, Mr. Ko said that the site would be bunded with proper drainage system to prevent any run-off from leaking into the sea. Assessments showed that the dioxin concentration at the two closest receptors, which were 100m away from To Kau Wan, would be 300 times lower than the ambient level. Mr. Ma appreciated that Member's concern over the possible delay of the decommissioning process. He said that one of the reasons for adopting off-site treatment was to avoid rushing the decommissioning process to make room for the infrastructural works. He assured Members that all the works at To Kau Wan would be subject to stringent precautionary measures.

36. The Chairman noted that carbon monoxide would be used as a surrogate in monitoring dioxin emissions. He asked about the correlation between the two and whether there were data to support it. In reply, Mr. Ko said that carbon monoxide was a good indicator of the completeness of combustion. Mr. Mike Pang said that there were a few research papers on the correlation between dioxin and carbon monoxide but he did not have the information at hand. Mr. Ko informed the meeting that carbon monoxide was also used as a surrogate measure for the Sydney Olympic Games site. At the 25ppm level, there would be investigation into the cause and at 100ppm level, the plant would be shut down.

37. A Member asked whether To Kau Wan was earmarked for development in coming years. In reply, Mr. Ma said that the site was part of the north Lantau long-term development project but it would not be developed for the next five years, therefore allowing sufficient time for the decontamination process.

38. While noting the proposed measures on site to safeguard against leakage of contaminants, a Member expressed concern about measures that would be adopted for the safety of workers handling the materials. In response, Mr. Ma said that the contract would stipulate that the transportation of the soil must be carried out by licensed chemical waste collection fleet. The workers would be trained in chemical waste handling and equipped with spill clean up kit and personal protective equipment.

Transportation risk

39. A Member pointed out that 30 laden trucks per day with two escort vehicles for each truck would increase the traffic load and hence the possibility of car accidents. She queried whether the risk for off-site treatment at To Kau Wan had been underestimated. In response, Mr. Ma said that the risk of having an accident during transportation was extremely low when comparing the 30 laden trucks per day on a dedicated haul road with an average of 1,800 to 2,000 vehicles per hour on a normal highway.

40. A Member asked about the chance of the container breaking and materials leaking out to the surroundings in the event of the worst-case scenario that there was an accident during transportation of condensate from To Kau Wan to CWTC. He also asked about the quantity of condensate on one laden truck. In response, Mr. Ko said that the condensate would be collected from To Kau Wan about three times per week, with approximately 1m3 (5 drums) per day. Of the 1m3, about two-thirds would be water and the rest heavy waste oil. The specifications of the drums would meet the United Nation standards, i.e. could withstand collision force falling from 1m above ground. For safety reason, the drums would be secured inside the container.

41. A Member asked about the risk of leakage of the drum as compared to normal loaded trucks on the road. In reply, Mr. Ko said that the risk would be 1,000 times lower than normal case.

42. A Member enquired about the specifications of the steel drums. In response, Mr. Ko said that the specifications of the drums would meet the requirements set out in Chemical Waste Regulations. Mr. Ma added that the contractor would be required to use real samples to carry out collision test before the works commenced. In response to the Chairman's question, Mr. Ko said that other than the 1m collision test, the best practice currently adopted in the United States did not specify the design for drums for carrying dioxin contaminated materials.

43. A Member pointed out that the transportation routes in the United States for contaminated materials would not pass through crowded urban areas as in Hong Kong. She therefore urged the project proponent to take into account local environments and adopt a higher standard. In response, Mr. Ma said that they would adopt additional measures on top of those practiced in the United States, for example, in providing escort vehicles to minimize the risk of car accidents.

Decommissioning of To Kau Wan treatment plant

44. In response to the Chairman's question, Mr. Simon Hui said that the decommissioning of the thermal desorption plant was included in the EIA report.

45. In response to a Member's enquiry, Mr. Ma said that the decommissioning was expected to start in early 2006 and would last for about six months. The site would be released for further development once it was tested and confirmed properly cleaned up. Mr. Patterson supplemented that according to his experience, the decommissioning process usually took two to three months.

46. In response to the Chairman's enquiry, Mr. Ko said that the thermal desorption plant at To Kau Wan would be a mobile one. There were over 150 such mobile plants in operation in the last 15 years and about 15 to 20 fixed plants in the United States.

47. A Member asked why the mobile plant would cost so much when it was a used one. In reply, Mr. Ko said that the cost figure included the shipping cost, operating cost, cost for the sophisticated air emission control units and testing for dioxin, etc.

Contingency plan for exceedances of emission

48. A Member said that there had been cases of exceedance of dioxin emission at CWTC and asked whether the project proponent was aware of CWTC's history of non-compliance. In response, Mr. Ko said that he had discussed with the operator of CWTC and EPD staff and was fully aware of the two exceedances in the past nine years. He noted that the concentration of dioxin, though exceeded the local standard of 0.1ng/m3, was lower than the United States's standard of 0.4 ng/m3. Mr. Mike Pang supplemented that investigations of the exceedances revealed that the second case was due to the malfunction of the carbon injection system. A dual carbon injection system was now in place to increase the level of precaution. Apart from that, emissions were also closely monitored by one monitoring station at the stack and three ambient monitoring stations at Tsing Yi, Tsuen Wan and Central.

49. In response to the Chairman's question, Mr. Mike Pang said that the Administration would carry out thorough investigation on the cause of exceedance but the time taken to identify the cause of exceedance would vary case by case. If the operator was found not complying with the requirements stipulated in the contract, he could be subject to prosecution.

50. A Member asked whether the frequency of monthly monitoring recommended in the EIA report could be increased. In response, Mr. Mike Pang said that the incineration of condensate was not continuous throughout the week and monthly monitoring was considered sufficient. Mr. Ko said that a batch of samples would be taken to CWTC for a performance test and the monitoring frequency would be reviewed when the results of the test were obtained.

51. A Member was happy to note the various proposed management measures to reduce the risk of contaminants leakage and dispersion. However, in view of the concern of the community, he suggested that a proper environmental management system should be set up to ensure the quality of the management of the whole process.

52. As there was no further enquiry, the Chairman thanked the project proponent for the presentation and discussion.[The project proponent team left the meeting at this juncture.]

Conclusion and recommendations of the Subcommittee

53. The Chairman asked if Members would support endorsing the EIA report.

54. A Member indicated that he would endorse the EIA report as there were sufficient precautionary and contingency measures.

55. A Member also supported the EIA report as he was convinced that the EIA was done in due diligence and the assessment of alternative treatment technologies and alternative sites for treatment was comprehensive.

56. A Member agreed that off-site treatment could eliminate the risk of rushing the decommissioning process and allow sufficient time for proper decontamination work and decommissioning of the plant. The risk during transportation was also acceptable. The proposed option in the EIA report involved the least risk and he would support the EIA report.

57. Another Member agreed with that Member. Although the underlying factor for selecting the option was not solely related to environmental considerations, she agreed that the proposed option was environmentally acceptable and she supported the EIA report.

58. A Member noted that he should abstain from voting but he suggested requesting the project proponent to set up a high standard environmental management system.

59. A Member objected to the EIA report. She was not satisfied that the project proponent recommended the thermal desorption option before the treatability test was completed. She said that To Kau Wan was not up to safety standards; the risk involved in transporting contaminated materials was unacceptable; and the safety standards should be set in the local context rather than that of overseas countries. In addition, the project proponent had not yet answered some queries raised by members of the LegCo EA Panel at its last meeting. Though on-site treatment would delay the opening of the Theme Park but that should not be a concern of the Subcommittee. She was worried that like the EIA of the Theme Park which was endorsed by the Council without detailed assessment of the decommissioning of the shipyard, the present EIA would be endorsed while there were still uncertainties. In view of the role of the Subcommittee, she urged Members to be cautious in endorsing the EIA report.

60. In response to that Member's comments regarding the EIA of the Theme Park, a Member recalled that the project proponent advised the Subcommittee at the meeting that there would be "no insurmountable problems" in the decommissioning of the Cheoy Lee Shipyard. On that understanding the Subcommittee did not raise objection to the proposal that the Cheoy Lee Shipyard should be subject to a separate EIA. The Chairman echoed the second Member's comment and said that in terms of surmountability, the present EIA was considered acceptable.

61. A Member suggested that conditions could be imposed on the proponent/contractor that they could not commence works until the treatability test on thermal desorption was completed. He also proposed that the project proponent should provide clear method statements for all stages of works of the project and for a robust EM&A programme.

62. The Chairman concluded that while noting a Member's objection, the Subcommittee would recommend the Council to endorse the EIA report with the following conditions:
 

Agenda Item 4 : Any Other Business

Informal dialogue

63. The Chairman suggested and Members agreed that the discussion be deferred to the next meeting.

64. A Member proposed to discuss at the next meeting how the Subcommittee should consider reports submitted by "independent" assessors engaged by the project proponent of an EIA study. In response, the Chairman said that as long as the reports were submitted by the project proponent under the same application, they should be considered as part of the submission.

Expertise advice

65. A Member enquired about the circumstances that the Council could invite assistance from experts on issues which Members had no expertise. In response, the Chairman said that there had been cases in which the Council invited advice from independent experts not related to any of the parties. He agreed that expertise advice could be drawn provided that the credentials of the experts were accepted by the Council. However, there might be resource implications on the part of the Administration. The Secretary said that as in the case of Sha Lo Tung and the Airport, the Secretariat would be happy to assist in inviting expertise opinions if the Council/Subcommittee considered it necessary and accepted the credentials of the experts concerned. Financial reward was not a pre-requisite for inviting expertise advice. Rather, the 60-day statutory time limit upon receiving an EIA report to advise Director of Environmental Protection of the comments on the report could be a constraint in seeking opinions outside the Council.

Agenda Item 5 : Date of Next Meeting

66. There was no EIA report scheduled for consideration at the meeting on 8 April 2002. The meeting would therefore be called off.

EIA Subcommittee Secretariat
April 2002