For discussion PWSC(97-98)4
on 23 April 1997

ITEM FOR PUBLIC WORKS SUBCOMMITTEE
OF FINANCE COMMITTEE

HEAD 705 - CIVIL ENGINEERING
Civil Engineering - Land development
480CL - Disposal of contaminated mud - management and capping of contaminated mud pit IV

Members are invited to recommend to Finance Committee the upgrading of 480CL to Category A at an estimated cost of $570.1 million in money-of-the-day prices for the management and capping of the fourth contaminated mud pit at East Sha Chau.

---

PROBLEM
PROPOSAL
PROJECT SCOPE AND NATURE
JUSTIFICATION
FINANCIAL IMPLICATIONS
PUBLIC CONSULTATION
ENVIRONMENTAL IMPLICATIONS
LAND ACQUISITION
BACKGROUND INFORMATION
Projects which need contaminated mud disposal facilities from 1997 to 2002
480CL - Disposal of contaminated mud - management and capping of contaminated mud pit IV

---

PROBLEM

The existing facilities for disposing of contaminated mud from on-going and planned projects will reach full capacity by mid-1997.

PROPOSAL

2. The Director of Civil Engineering, with the support of the Secretary for Planning, Environment and Lands, proposes to upgrade 480CL to Category A at an estimated cost of $570.1 million in money-of-the-day (MOD) prices for the management and capping of a fourth contaminated mud pit (CMP IV) at East Sha Chau.

PROJECT SCOPE AND NATURE

3. The scope of the project comprises -

1. bund construction;
2. on-site control of mud disposal activities;
3. capping works; and
4. environmental monitoring during mud disposal operations and for a period of two years following completion of the disposal programme.

JUSTIFICATION

4. Since 1992, we have disposed of contaminated mud in dredged seabed pits at East Sha Chau. To date, we have used three groups of contaminated mud pits, namely CMP I, II and III comprising a total of nine sub-pits as shown on the location plan at Enclosure 1. The last sub-pit of this series, CMP IIId, will be filled up by mid-1997 at which time we will need to make available a new group of seabed sub-pits, namely CMP IV to cater for the disposal of contaminated mud arising from on-going and planned projects. A list of those projects which we have identified will generate contaminated mud requiring disposal between 1997 and 2002 is at Enclosure 2.

5. The implementation of projects at Enclosure 2 will be adversely affected if the contaminated mud disposal facilities are not available in time, that is, by mid-1997. In particular, on-going and planned flood protection works in the New Territories and harbour maintenance dredging works will either come to a halt or not be able to proceed. In the case of on-going projects, the failure to provide contaminated mud disposal facilities may lead to contractual claims against the Government.

6. The design capacity of CMP IV is about 29 million cubic metres, which should meet the projected demand for contaminated mud disposal up to 2002. Unlike CMP I, II & III which were formed by dredging pits in the seabed, we will form CMP IV by using existing seabed borrow pits left empty following the construction of Chek Lap Kok Airport. Such an approach will result in significant cost savings. For optimal control of mud disposal activities, we will sub-divide CMP IV into three sub-pits by constructing a bund between CMP IVa and CMP IVb and enlarging the existing bund between CMP IVb and CMP IVc. We will isolate all deposited contaminated mud from the marine environment by capping the pits with clean sand and uncontaminated mud.

7. As CMP IV will be a multi-user disposal facility, we need to assume on-site control of mud disposal activities to ensure that the contaminated mud is deposited in the correct way and in the correct position.

8. Since 1993, we have monitored the environmental impact of disposal operations in CMPs. We plan to continue such monitoring during the disposal operations at CMP IV and for about two years thereafter. We will engage consultants to undertake this task which will comprise sampling and testing of the water, sediment and marine biota at East Sha Chau.

FINANCIAL IMPLICATIONS

9. We estimate the capital cost of the project to be $570.1 million in MOD prices (see paragraph 10 below), made up as follows -

A breakdown by man months of the estimate for consultants’ fees is at Enclosure 3.

10. Subject to approval, we will phase expenditure as follows -

11. We have derived the MOD estimate on the basis of the Government’s forecasts of trend labour and construction prices for the period 1997 to 2005. We will tender the on-site control of mud disposal activities, bund construction and capping works under standard remeasurement contracts with provision for inflation adjustment because of the uncertainty of the rate at which disposable mud will be received, the seabed conditions and the fact that the duration of the contract period will be greater than 21 months. We will award the environmental monitoring consultancy on a lump-sum basis with provision for inflation adjustment as the contract period will be greater than 12 months.

12. The proposed works will not give rise to any recurrent expenditure.

PUBLIC CONSULTATION

13. The East Sha Chau contaminated mud disposal area, which covers the proposed CMP IV, was authorised under the Foreshore and Seabed (Reclamations) Ordinance in February 1992.

14. We have briefed the Advisory Council on the Environment (ACE) regularly on contaminated mud disposal operations at East Sha Chau since ACE’s predecessor, the Environmental Pollution Advisory Committee, endorsed the use of the facility in 1993. On 25 November 1996, we provided ACE with the most recent update on mud disposal operations which included the programme for CMP IV. On 3 March 1997 and 24 March 1997, we presented the findings of the Environmental Impact Assessment (EIA) for CMP IV to the EIA Subcommittee of ACE and ACE respectively. ACE endorsed the EIA on 24 March 1997.

15. On 25 February 1997, we briefed the Legislative Council Panel on Environmental Affairs on mud disposal activities at East Sha Chau and subsequently provided the Panel with additional information concerning site selection and alternative disposal options. The Panel noted the consultants’ conclusion that there was no evidence of direct or indirect links between contaminated mud disposal at East Sha Chau and the contaminants found in the tissue of Chinese White Dolphins.

16. We consulted the Environmental Improvement and District Development Committee (EIDDC) of the Tuen Mun District Board on 10 January 1997. The Committee expressed concern about the environmental impact of the proposals for CMP IV. On 5 March 1997 officials accompanied Committee members on a site visit to the disposal area. Subsequently, the EIDDC discussed the proposal at a meeting held on 7 March 1997 and the Committee accepted the proposal with reservations, urging the Government to -

1. keep the environmental nuisance to a minimum;
2. ensure that the operational guidelines would be followed strictly;
3. submit reports to the EIDDC regularly; and
4. endeavour to restore the concerned seabed area to its original ecological environment and discontinue marine disposal at East Sha Chau after CMP IV is filled up.

17. We presented details of the proposed project to the Islands District Board on 17 February 1997. The Board had no objection to the proposal.

18. We have regularly briefed the Capture Fisheries Subcommittee of the Advisory Committee on Agriculture and Fisheries on the operation of the East Sha Chau contaminated mud disposal facilities and the proposed CMP IV project. The Subcommittee did not object to the proposed project at its meeting on
4 February 1997.

19. We also regularly brief the Marine Mammal Conservation Working Group¹ on the progress of contaminated mud disposal operations. The Working Group has no objection to the continuation of disposal activities at East Sha Chau.

ENVIRONMENTAL IMPLICATIONS

20. An intensive environmental monitoring programme for contaminated mud disposal at East Sha Chau covering water, sediment and biota commenced in October 1992 to determine whether the disposal activities would have any adverse environmental impacts. A working group comprising representatives from Environmental Protection Department, Agriculture and Fisheries Department, Civil Engineering Department and New Airport Projects Co-ordination Office is overseeing the environmental monitoring programme. The monitoring results over the past four years have indicated no adverse trends. This indicates that the capped pits have effectively isolated the contaminated mud from the marine environment.

21. In 1995, the London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matters adopted the "Dredged Material Assessment Framework" for managing the dumping of contaminated mud. In 1996, we completed a consultancy study, "Review of Contaminated Mud Disposal Strategy and Status Report on Contaminated Mud Disposal Facility at East Sha Chau", funded under 454CL "Fill Management Study, phase VI - investigation for further fill resources; seabed reinstatement, dredging and marine disposal, environmental and physical studies" to review our existing disposal arrangements in the light of this new and rigorous management framework. The study reaffirmed that the existing contained marine disposal method was environmentally acceptable under the current management and monitoring arrangements, and that East Sha Chau was a suitable, and the preferred, area for contained marine disposal of contaminated mud. Risk assessments, undertaken as part of the study, also indicated that the disposal activities at East Sha Chau did not create public health or ecological risks, including risks to Chinese White Dolphins. We presented the results of this study to ACE in May 1996. Members had no adverse comments.

22. New data on contaminant levels in the body tissue of Chinese White Dolphins became available after May 1996. We then commissioned the consultants to further assess the risk to Chinese White Dolphins. The study, funded under 454CL, concluded that there was no evidence of direct or indirect links between contaminated mud disposal at East Sha Chau and contaminants found in Chinese White Dolphin tissue. On 25 November 1996, we presented the results of this assessment to ACE. Members of ACE had no adverse comment on the findings of the assessment.

23. We completed an EIA for the proposed CMP IV in January 1997. The EIA concluded that disposal of contaminated mud in CMP IV would be environmentally acceptable, and recommended specific controls and an environmental monitoring and audit programme for the operation of CMP IV. As indicated in paragraph 14 above, ACE endorsed the EIA on 24 March 1997.

24. We will implement the operational controls and an environmental monitoring and audit programme, during the operation of CMP IV and for two years thereafter, at an estimated cost of $119 million at December 1996 prices. These steps will ensure that the environmental impacts arising from the proposed project are kept within established guidelines and the assumptions in the EIA. We have included this cost in the project estimate.

LAND ACQUISITION

25. The proposed project does not require land acquisition.

BACKGROUND INFORMATION

26. In May 1993, we upgraded 401CL "Disposal of contaminated mud - dredging, management and capping of contaminated mud pit II" to Category A at $435 million for the dredging, management and capping of CMP II at East Sha Chau.

27. In March 1994, we upgraded 421CL "Disposal of contaminated mud - dredging, management and capping of contaminated mud pit III" to Category A at $151 million for the dredging, management and capping of CMP III at East Sha Chau.

28. We upgraded 480CL to Category B in March 1997.

29. We have substantially completed the detailed design and tender drawings using in-house staff resources. We plan to invite tenders in May 1997 in order that CMP IV will be available to receive the first deposits of contaminated mud by mid-1997.

30. We plan to start the proposed works in July 1997 for completion in mid 2002.

(DD1096)

1 -- This Working Group is chaired by a representative of Director of Agriculture and Fisheries (DAF). Its membership includes officials from relevant government departments and representatives from green groups, fishermen and academics. The Working Group advises DAF on technical and other mattersconcerning conservation of marine mammels.

---

Enclosure 2 to PWSC(97-98)4

Projects which need contaminated mud disposal facilities from 1997 to 2002

Nature of Works	Contract Name (Project Code)	Start	End	Volume of Contaminated Mud (Cubic metres)
FLOOD PROTECTION/DRAINAGE	Yuen Long/Kam Tin Drainage Channels - Stage 1, Phase 2 (43CD)	01/96	03/98	40 000
	Sutlej River Training Stage II	01/96	11/97	5 000
	Village Flood Protection Works for Sha Po Tsuen (71CD)	03/96	02/98	8 000
	Yuen Long/Kam Tin Drainage Channels - Stage II, Phase 1 (22CD)	03/96	09/98	16 000
	Ngau Tam Mei Drainage Channel - Phase 1 (29CD)	06/96	02/01	100 000
	Village Flood Protection Works for San Tin Village	12/96	05/99	44 000
	Shek Wu Hui Development - River Training in Areas 30B & 33 (Part) (87CL)	01/97	12/98	20 000
	Village Flood Protection Works for Ha Mei Shan Tsuen (473CL)	03/97	03/98	10 000
	Village Flood Protection Works for Pok Wai (30CD)	11/97	07/99	23 000
	Yuen Long/Kam Tin Drainage Channels, Stage II, Phase 2 (81CD)	01/98	12/99	60 000
	Indus River Training Stage I (53CD)	06/98	12/99	20 000
	Ngau Tam Mei Drainage Channel - Phase 2 (29CD)	02/99	02/01	40 000
	Yuen Long/Kam Tin Drainage Channels - Stage II, Phase 3 (81CD)	02/99	02/01	40 000
	Village Flood Protection Work for Mai Po Lo Wai, Mai Po San Tsuen (30CD)	07/99	12/99	10 000
	Indus River Training Stage II (53CD)	07/99	12/99	10 000
	Village Flood Protection for Yuen Long/Kam Tin & Ngau Tam Mei Stage II - Remaining Villages	08/99	12/03	4 000
	Village Flood Protection for Yuen Long/Kam Tin & Ngau Tam Mei Stage II - Wang Chau	08/99	07/01	15 000
	Yuen Long/Kam Tin Drainage Channels - Remainder, Phase 4 (22CD)	11/99	05/02	16 000
	Yuen Long Bypass Floodway (70CD)	03/01	03/04	5 000
	Tin Shui Wai Village Flood Protection - Drainage Access Road to Sheung Cheung Wai (227CL)	04/01	03/02	10 000
HARBOUR MAINTENANCE	Maintenance Dredging at Kwai Chung Container Terminals	05/94	12/97	8 000
DREDGING, SEAWALLS & PIERS	Dredging of Northern Fairway - Remaining	01/96	12/98	400 000
	Maintenance Dredging at Kwun Tong Public Cargo Working Area	05/96	12/00	6 000
	Dredging in Hung Hom Fairway	01/97	12/98	80 000
	Maintenance Dredging at Sha Tau Kok Typhoon Shelter Anchorage	01/97	12/97	70 000
	Maintenance Dredging at Tuen Mun Typhoon Shelter Area 16 PW	01/97	12/97	4 000
	Maintenance Dredging of Approach to Kwai Chung Container Terminals	01/97	12/97	69 000
	Dredging of Shing Mun River Channel	01/98	12/00	400 000
	Seafrontage Works at Quarry Bay and Cha Kwo Ling (96-97)	03/98	06/98	6 000
	Seafrontage Works at Quarry Bay and Cha Kwo Ling (96-97)	03/00	06/00	6 000
	Seafrontage Works at Quarry Bay and Cha Kwo Ling (96-97)	03/02	06/02	6 000
TYPHOON SHELTER/ANCHORAGE	Dredging Area of Kellett Bank for Mooring Buoys	05/98	12/98	3 000 000
	Construction of Siu Lam Typhoon Shelter	04/99	12/99	700 000
	Construction of Peng Chau Typhoon Shelter	06/99	12/01	700 000
WATER & SEWERAGE	Sham Tseng Sewage, Treatment Plant & Submarine Outfall	01/96	06/98	16 000
	Central and Wan Chai East Pumping Station & Screening Plant	11/96	07/97	3 000
	Tung Chung Development - Water Supplies Department Salt Water Pumping Station	03/97	11/98	300 000
ROAD WORKS	Tai O Creek Improvement Phase I	03/96	03/98	200 000
	Duplicate Tsing Yi South Bridge	03/96	01/98	22 000
	Tai O Development - Northeast Riverwall & Reclamation, Creek Improvement Stage I	04/97	04/99	70 000
	Yuen Long - Tuen Mun Corridor Engineering Works for Ha Mei Sun Tsuen (29CD)	07/98	09/00	10 000
	Widening of Tolo Highway & Traffic Surveillance & Information System	12/98	12/00	300 000
	Yuen Long - Tuen Mun Corridor Engineering Works for Sheung Cheung Wai (213CL)	04/00	03/02	10 000
NEW TOWN DEVELOPMENTS	Tuen Mun Area 38 Special Industries Development - Reclamation & Construction of Roads & Drain, Stage II	04/97	01/98	189 000
	Tseung Kwan O - Town Centre Extension Reclamation (Stage II)	04/97	04/00	90 000
	Tin Shui Wai Development - Site Formation in Areas 101-108, 109 (Part), 110, 111 (550CL)	09/97	10/98	20 000
	Site Formation for Yuen Long Wholesale Food Market - 455CL	02/98	10/99	40 000
	Tin Shui Wai Development, Drainage Channel & Site Formation Area 109 (Part) & 112-123	04/99	09/03	260 000
	Tseung Kwan O, Phase III - Western Coast Road	10/99	09/00	100 000
	Tsuen Wan Bay Further Reclamation, Area 35, Tsuen Wan	03/00	03/03	3 150 000
	Tseung Kwan O, Phase III - Area 131	04/00	12/02	300 000
	Tseung Kwan O, Phase III - Public Cargo Working Area & Breakwater	04/00	03/02	100 000
	Tung Chung Development - Phase 3	01/01	12/02	300 000
OTHERS	Pak Shek Kok Reclamation for Public Dumping	10/96	01/98	100 000
	River Trade Terminal	01/97	12/97	200 000
	Tseung Kwan O Port Development Area 137 - Site Completion	05/97	12/97	29 000
	Tseung Kwan O Port Development Area 137 (Fat Tong O) - Remaining Work	09/97	12/97	40 000
	Tuen Mun Port Development (Castle Peak) Phase I	04/98	02/01	3 320 000
	Reclamation Works for District Open Space & GIC Facilities in North Tsing Yi	08/98	03/99	300 000
	West Kowloon Reclamation - Main Works (Remainder) Contract VI (YMG)	07/00	08/00	80 000
	Kowloon Point Development	01/01	12/05	100 000
	Central Reclamation, Phase III	01/02	12/03	210 000
	Lantau Port Development - Advance Reclamation Works	-	-	6 000
	Lantau Port Development - Approach Channel Dredging	-	-	1 500 000
	Lantau Port Development Phase I - Breakwater	-	-	300 000
	Lantau Port Development - Back-up Area for CT10	-	-	40 000
	Container Terminal No. 10 (Dredged Scheme)	-	-	310 000
	Container Terminal No. 11 (Dredged Scheme)	-	-	60 000

(DD1096)

---

Enclosure 3 to PWSC(97-98)4

480CL - Disposal of contaminated mud - management and capping of contaminated mud pit IV

Breakdown of estimates for consultants’ fees

Notes

(1) A multiplier factor of 3 is applied to the average MPS point to arrive at the full staff costs including the consultants’ overheads and profit, as the staff will be employed in the consultants’ offices. (At 1.4.96, MPS pt. 42 = $60,265 p.m. and MPS pt. 18 = $20,505 p.m.).

(2) Out-of-pocket expenses are the actual costs incurred. The consultants are not entitled to any additional payment for overheads or profit in respect of these items.

(3) The figures given above are only estimates, and the actual man months and actual fees can only be obtained after we have selected the consultants through the usual competitive bidding system.

(DD1096)

---