FCR(1999-2000)18

For discussion
on 11 June 1999

HEAD 43 - CIVIL ENGINEERING DEPARTMENT
Subhead 700 General other non-recurrent

Members are invited to approve a new commitment of $17.1 million in money-of-the-day prices for the monitoring of two new uncontaminated mud disposal sites at the seafloors south of Tsing Yi and north of Lantau.

PROBLEM

We need to make available new sites to meet the demand for the disposal of uncontaminated mud¹.

PROPOSAL

2. The Director of Civil Engineering (DCE), with the support of the Secretary for Works, proposes to create a new commitment at an estimated cost of $17.1 million in money-of-the-day (MOD) prices for the monitoring of two new uncontaminated mud disposal sites.

JUSTIFICATION

3. Since 1992, the Civil Engineering Department (CED) has been managing two open seafloor multi-user disposal sites south of Cheung Chau and east of Ninepins for uncontaminated mud from all public works projects. Mud generated from private projects is also disposed of at these sites but this contributes to less than 1% of the total quantity. CED estimates that the available capacity of the two sites will be exhausted by the end of 1999. At the same time, CED /forecasts .....forecasts that the yearly uncontaminated mud disposal requirement will stay at above 30 million cubic metres in the next few years. (Details of the forecast are at Enclosure 1.) There is thus an urgent need to identify new sites for the disposal of uncontaminated mud. The only practical option for disposal of the large volumes of uncontaminated mud is marine disposal in open seafloor sites or empty sand borrow pits.

4. CED has identified two new disposal sites, with a total disposal capacity of about 50 million cubic metres, at the seafloors south of Tsing Yi and north of Lantau as shown in the location map at Enclosure 2. They are previous marine sand borrow pits left empty following sand extraction. The two disposal sites have to be made available within 1999. Otherwise there would be unbearable consequences on the delivery of public works projects. In particular, the regular maintenance dredging of ports and navigational fairways for maritime activities will be adversely affected if there is insufficient capacity to dispose of the uncontaminated mud.

5. To allow mud disposal at the two new sites, the Director of Environmental Protection requires that a monitoring scheme be put in place for regular water quality, bathymetric and ecological monitoring² in accordance with the environmental monitoring and audit programme recommended by the Environmental Impact Assessment (EIA) studies. This is to ensure that the new international standards for managing mud disposal facilities adopted by the London Convention on the Prevention of Marine Pollution by Dumping of Wastes and Other Matter, which applies to Hong Kong, will be met.

6. DCE therefore proposes to set up a system in accordance with the monitoring and audit programme recommended by the EIA study for monitoring the use of the two sites starting from September 1999 for five years within which period their capacity is likely to be exhausted.

7. CED will employ specialist contractors to undertake the monitoring fieldwork. CED staff will be responsible for site supervision of data collection and interpretation of the water quality and bathymetric monitoring results. CED will employ an environmental consultant to assess the ecological monitoring results because the department lacks expertise in this field.

FINANCIAL IMPLICATIONS

8. We estimate the total cost of the project to be $17.1 million in MOD prices, made up as follows -

9. The funding requested is to implement the monitoring programme at the two sites for a period of about five years. The average cost is about $0.34 per cubic metre³ of mud disposed of. Apart from the consultant's fee of $3 million for assessing the ecological monitoring results, all the estimated expenses are for the engagement of survey vessels, monitoring equipment and qualified operators and personnel to collect water quality, bathymetric and marine ecological data.

10. As regards paragraph 8(a), the cost of $7.4 million is for engaging contractors to conduct water quality monitoring of the two sites, each for two days per month. The cost calculation is based on an existing term contract.

11. As regards paragraph 8(b), the cost of $1.6 million is for engaging contractors to conduct bathymetric monitoring to ensure that mud is evenly spread inside the pits. At each site, bathymetric survey will be carried out twice per year. The cost is dependent on the surface area of disposal sites and the estimate is based on an existing term contract.

12. As regards paragraph 8(c), the cost of $6 million is composed of two elements. An estimated $3 million is for engaging contractors to conduct ecological monitoring around the disposal sites. Another estimated $3 million is for hiring consultants to independently interpret the ecological monitoring results produced by the contractor and to assess the seabed recovery. This monitoring approach will ensure that we can detect any ecological impact resulting from disposal operations and determine whether operational modifications are necessary.

13. As regards paragraph 8(d), the cost of $2.1 million is an inflation allowance. We shall tender the monitoring work under standard remeasurement contracts with provision for inflation adjustment because the duration of the contract period will be longer than 21 months. The cost of monitoring is independent of the actual amount of mud intake. We shall award the consultancy on a lump-sum basis with provision for inflation adjustment as the contract will be longer than 12 months.

14. A breakdown of the costs is at Enclosure 3. A breakdown of the consultants' fees is at Enclosure 4.

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

16. The proposed project will not give rise to any recurrent expenditure.

ENVIRONMENTAL IMPLICATIONS

17. We have completed an EIA study for the two new sites, which was funded under Public Works Item 5454CL "Fill Management Study, Phase VI - investigation for further fill resources, seabed reinstatement, dredging and marine disposal, environmental and physical studies". The EIA study included assessments of water quality, marine ecology, fisheries, air quality and noise.

18. The EIA study concluded that with the implementation of the proposed operations plan, the empty pits at south of Tsing Yi and north of Lantau would be environmentally acceptable for disposal of uncontaminated mud. The environmental monitoring and audit programme will allow early detection of any adverse environmental impacts and enable immediate implementation of mitigation measures. The Advisory Council on the Environment (ACE) endorsed the EIA study and the recommended monitoring and audit programme on 9 February 1996.

19. CED undertook a full scale disposal trial at south of Tsing Yi (1996-1997) and north of Lantau (1997-1998) to assess whether environmental impacts associated with mud disposal operations were in accordance with predictions made in the EIA study. No adverse water quality impacts were detected at the monitoring stations during the disposal trial which demonstrated the effectiveness of the operation plan and the monitoring programme.

20. Backfilling the empty pits has the benefits of restoring the seabed to its original state to provide routine and emergency ship anchorage areas. It would assist full recovery of the sea-bottom organisms and render about 370 hectares of seabed suitable for trawling. These would have long-term benefits to the sea-bottom fisheries.

BACKGROUND INFORMATION

21. On 15 January 1999, Finance Committee discussed the funding application for the monitoring of three new uncontaminated mud disposal sites at the seafloors south of Tsing Yi, north of Lantau and east of Tung Lung Chau. The Committee recommended that we should first present the case to the Panel on Environmental Affairs. Members of the Panel discussed the matter at a meeting on 5 February 1999 and indicated no objection to the proposed sites at south of Tsing Yi and north of Lantau. We are separately considering views expressed on the site east of Tung Lung Chau.

22. Besides seeking ACE's endorsement of the EIA studies, we advised the Aquaculture and Capture Fisheries Subcommittees of the Advisory Committee on Agriculture and Fisheries at their regular meetings about the use of the two sites for disposal of uncontaminated mud. Committee members did not raise any objection to the backfilling project.

23. The two proposed sites are ready to receive uncontaminated mud.

Works Bureau
June 1999

Enclosure 3 to FCR(1999-2000)18

The estimated cost is as follows -

	Area km2	Bathymetry ($ million)	Water quality ($ million)	Ecology ($ million)	Total ($ million)
South of Tsing Yi	8	0.24	0.74	0.6	1.58
North of Lantau	3	0.09	0.74	0.6	1.43
					______
Cost per year					3.01
					______
Say					3.0
					______
Total cost for five years					15.0
Inflation allowance					2.1
					______
Total					17.1	(at money-of- the-day prices)
					______

Notes :

- The cost of monitoring is independent of the actual disposal volume.

- Bathymetric monitoring cost is calculated based on similar types of survey for which the average cost was $15,000 per square kilometre. At each site, bathymetric survey will be carried out twice per year.

- Water quality monitoring cost per disposal site is calculated based on an existing term contract at $28,000 per day plus 10% (for price adjustment), for two days per month per site.

- Ecological monitoring and consultancy costs are calculated based on a similar existing contract of $4.5 million for eight sites. The pro-rata charge for doing similar types of work at each site is about $0.6 million.

Enclosure 4 to FCR(1999-2000)18

Breakdown of estimates for consultants' fees (at October 1998 prices) -

		Estimated man-months	Average MPS salary point	Multiplier factor	Estimated fee ($ million)
(a) Interpret ecological monitoring results	Professional Technical	15.0 5.0	40 16	2.4 2.4	2.260 0.252
(b) Assess seabed recovery	Professional Technical	2.4 2.4	40 16	2.4 2.4	0.362 0.121
					_______
Total consultants' fees					2.995
					_______
Say					3.0
					_______

Notes :

A multiplier factor of 2.4 is applied to the average Master Pay Scale (MPS) 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 April 1998, MPS point 40 = $62,780 per month and MPS point 16 = $21,010 per month.)

1. Uncontaminated mud refers to dredged materials suitable for open sea disposal without the requirement of capping.

2. Bathymetric surveys measure backfilling levels to ensure that mud is evenly spread and that no high spots are formed inside the pits. Ecological monitoring refers to the study of the number and variety of marine organisms. This monitoring is designed to detect any ecological impact resulting from disposal operations and to determine whether operational modifications are necessary.

3. The average cost is calculated as the total estimated cost divided by the capacity of the two disposal sites stated in paragraph 4 (i.e. $17,100,000/50 000 000 cubic metres = $0.34 per cubic metre).