For discussion PWSC(97-98)57
on 4 November 1997

ITEM FOR PUBLIC WORKS SUBCOMMITTEE OF FINANCE COMMITTEE

HEAD 709 - WATERWORKS
Water Supplies - Fresh water supplies
227WF - Extension of Au Tau treatment works supply system - mainlaying between Au Tau treatment works and Yuen Long Town

Members are invited to recommend to Finance Committee -

1. the upgrading of part of 227WF, entitled "Mainlaying between Au Tau treatment works and Yuen Long Town - advance work near Fung Yau Street East" to Category A at an estimated cost of $27.5 million in money-of-the-day prices; and
2. the retention of the remainder of 227WF, retitled "Mainlaying between Au Tau treatment works and Yuen Long Town - remaining works", in Category B.

PROBLEM

By 2003, the existing trunk main between Au Tau treatment works and Yuen Long Town will not be able to cope with the anticipated increase in water demand arising from the planned developments in the Tuen Mun - Yuen Long Corridor and the north-western part of Tuen Mun.

PROPOSAL

2. The Director of Water Supplies (DWS), with the support of the Secretary for Works, proposes to upgrade part of 227WF to Category A at an estimated cost of $27.5 million in money-of-the-day (MOD) prices for the laying of a fresh water main in conjunction with roadworks along a proposed road near Fung Yau Street East.

PROJECT SCOPE AND NATURE

3. The full scope of works under 227WF comprises the laying of about 5 000 metres of a 1 400 millimetres diameter fresh water trunk main between Au Tau treatment works and Yuen Long Town along Shan Ha Road, Ma Tin Road, Ma Tong Road, Fung Yau Street South, Fung Yau Street East, Castle Peak Road, Kam Tin Road and a proposed road near Fung Yau Street East.

4. The part of 227WF we now propose to upgrade to Category A comprises the laying of about 500 metres of 1 400 millimetres diameter fresh water trunk main along a proposed road near Fung Yau Street East under the works in paragraph 3 above.

JUSTIFICATION

5. At present, the Au Tau treatment works supplies fresh water to Yuen Long including Kam Tin and Shek Kong. Upon completion of the construction works under 229WF¹ "Tan Kwai Tsuen fresh water service reservoir stage II and mainlaying works in Tuen Mun area 52" and 34WF² "Additional trunk transfer facilities between Yuen Long and Tuen Mun" in 2000, its supply zone will further extend to cover Tuen Mun/Yuen Long Corridor and the north-western part of Tuen Mun. DWS anticipates that the capacity of the existing trunk main between Au Tau treatment works and Yuen Long Town (about 236 000 cubic metres per day) will be unable to cope with the anticipated demand of 237 000 cubic metres per day by 2003 in the area. DWS therefore plans to provide additional trunk transfer facilities as detailed in paragraph 3 above to meet the water demand of the planned developments in the areas up to the year 2007.

6. The Director of Territory Development (DTD) has a site formation contract under 455CL³ "Site formation for Yuen Long combined wholesale food market" which includes the formation of a new road near Fung Yau Street East. The mainlaying works described in paragraph 4 above will fall within the project boundaries of 455CL. To avoid interface problems arising from two contractors working on the same site, we will incorporate this section of mainlaying works into the site formation contract under 455CL.

FINANCIAL IMPLICATIONS

7. We estimate the capital cost of the project to be $27.5 million in MOD prices (see paragraph 8 below), made up as follows -

A breakdown by man months of the estimate for consultants' fees including resident site staff expenses is at the Enclosure.

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

9. We have derived the MOD estimates on the basis of the Government's forecast of trend labour and construction prices for the period 1998 to 2001. We will incorporate the proposed mainlaying works into DTD's site formation contract on a remeasurement basis with no provision for inflation adjustment because the construction period will shorter than 21 months.

10. We estimate the additional annually recurrent expenditure to be $29,700.

11. This project by itself would lead to an increase in water charges by a maximum of 0.02% in real terms by 2001⁴.

PUBLIC CONSULTATION

12. We consulted the Environmental Improvement Committee of the Yuen Long District Board on 22 May 1997. The Committee supported the project.

ENVIRONMENTAL IMPLICATIONS

13. The Director of Environmental Protection vetted the Preliminary Environmental Review (PER) conducted by DWS in February 1996. The PER concluded that the project would have no long term environmental impacts and no Environmental Impact Assessment is required. We will control noise, dust and site run-off nuisances during construction to comply with established standards and guidelines through the implementation of mitigation measures in relevant contracts.

LAND ACQUISITION

14. The proposed works do not require land acquisition.

BACKGROUND INFORMATION

15. We upgraded 227WF to Category B in September 1996. As regards the works which we now propose to upgrade to Category A, DWS has completed the detailed design for the proposed mainlaying works by engaging consultants at a cost of $830,000 which we have charged to block allocation Subhead 9100WX "Waterworks, studies and investigations for items in Category D of the Public Works Programme". We plan to start the proposed mainlaying works in June 1998 for completion in February 1999 to tie in with the roadworks programme under 455CL.

16. DWS is continuing with the design works for the remaining trunk main sections under the remaining part of 227WF with a target to start the construction works in early 1999 for completion in early 2003.

Works Bureau
October 1997

1 -- In January 1997, Finance Committee approved the upgrading of229WF to Category A at an estimated cost of $104.1 million in money-of-the-day prices. The scope of works of 229WF comprises the construction of the Tan Kwai Tsuen fresh water service reservoir stage II and construction of part of the water trunk mains to transfer treated water from Au Tau treatment works in Yuen Long to Tuen Mun.
2 -- 34WF comprises the construction of a pumping station at Tan Kwai Tsuen, laying of approximately 2.9 kilometres of 1400 mm diameter fresh water trunk mains between Tuen Mun and Tan Kwai Tsuen, and laying of approximately 2.9 kilometres of 1400 mm diameter fresh water trunk mains between Yuen Long and Tan Kwai Tsuen. The estimated project cost is $299 million at December 1996 prices. We plan to seek PWSC's endorsement to upgrade part of 34WF to Category A on 12 November 1997.
3 -- We upgraded 455CL to Category B in January 1996. The estimated cost is $31.9 million at Decmeber 1996 prices. A related paper, PWSC(97-98)54, for the upgrading of 455CL under Head 707 to Category A is also submitted for Members' approval at this meeting.
4 -- The increase in water charges is calculated on the assumption that the demand remains static during the period from 1997 to 2001 and the amount of Government subsidy into waterworks operataions is to be contained at the present price level.

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Enclosure to PWSC(97-98)57

227WF - Extension of Au Tau treatment works supply system - mainlaying between Au Tau treatment works and Yuen Long Town

DETAILS OF CONSULTANTS' FEES

Breakdown of estimates for consultants' fees

MPS = Master Pay Scale

Notes

1. A multiplier factor of 3.0 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. 40 = $55,390 p.m. and MPS pt. 16 = $18,595 p.m.). A multiplier factor of 2.1 is applied to the average MPS in the case of site staff supplied by the consultants.

2. The figures given above are based on estimates prepared by the Director of Water Supplies. Since the consultancy works for this project will be included as part of the overall consultancy agreement for the development in Yuen Long District, we will only know the actual consultants' fees upon finalisation of the account of the works contract.