Advisory Council on the Environment

Report on the 73rd Environmental Impact Assessment Subcommittee Meeting

(ACE Paper 28/2002)
For advice


At its meeting held on 5 August 2002, the Subcommittee considered the environmental impact assessment (EIA) report on Deep Bay Link (DBL).


2. Members are requested to advise whether the EIA report should be endorsed.


EIA report on Deep Bay Link
(ACE-EIA Paper 14/2002)

Need for the project

3. The Hong Kong Special Administrative Region and the Shenzhen government proposed to provide a fourth vehicular boundary crossing which is now known as the Shenzhen Western Corridor (SWC) to meet the present and expected future traffic demand between the two areas. DBL will serve as the strategic highway linking SWC to Hong Kong's highway network.

Description of the project

4. DBL is a 5.4 km long dual 3-lane carriageway connecting SWC at Ngau Hom Shek to the Yuen Long Highway at Lam Tei where traffic could gain access to the road network including Route 3 Country Park Section to the east and Tuen Mun Road to the west. It will also provide access to Ha Tsuen and the proposed Hung Shui Kiu New Town.

Views and recommendations of EIA Subcommittee

5. Members' concerns on the project related mainly to the submission of the EIA report of the project in isolation of the SWC project; air quality impact during operational stage; relationship between Air Quality objectives (AQOs) and impact on health; cumulative impact of future road networks; cumulative impact on Ramsar site; loss of egretry at Ngau Hom Shek; loss of fishponds; residual traffic noise impact during construction stage; visual impact of noise barriers during operational stage and planting of native species of trees.

Why the EIA reports of DBL and SWC were not submitted together

6. Members queried why the EIA report of DBL and SWC were not submitted together given that the two projects were directly linked. There were concerns that in the absence of an EIA on SWC, the endorsement of the DBL project would pre-empt Members' acceptance of the landing point of SWC at Ngau Hom Shek. Also, separate submission of the EIA reports of the two projects would deprive Members' of the opportunity to consider the overall cumulative impacts of the two projects. The project proponent explained that due to the high urgency of the DBL project, it was necessary to start related preparatory work earlier. The landing point at Ngau Hom Shek had been assessed during the Crosslink Further study and discussed with Members several months ago during an informal dialogue. As for cumulative impacts, Table 7.31 of Volume 1 of the EIA report had listed out projects which together with DBL may produce cumulative effects and also the details of the potential cumulative impacts within the area of the current project.

Air quality impact during operational stage

7. On air quality impact during operational phase, the project proponent team pointed out that air sensitive receivers within 500m from the project boundary would not be subject to any exceedance in AQOs during the operational phase. The assessment was based on a conservative assumption that all cross boundary vehicles on the road network would use fuel with higher sulphur content. Another conservative assumption adopted was the emission factors in the year 2011 in designing the traffic flow in 2021.

Relationship between AQOs and impact on health

8. Some Members commented that AQOs was a crude and unreliable indicator as far as health was concerned. Even though the project complied with AQOs during the construction and the operational stage, it did not necessarily mean that it would not have any adverse impact on health. That said, Members were aware that under the Technical Memorandum, the criteria for evaluating air quality was meeting AQOs established under the Air Pollution Control Ordinance. Unless there is a change in policy, projects meeting the AQOs should not be challenged as not being up to the required air quality standard.

Cumulative impact of future road network

9. On the cumulative impact of related road network on air quality, the project proponent team pointed out that the air quality modeling had taken into account the impact of Deep Bay Link as well as other future road network. .

Cumulative impact on Ramsar site

10. On cumulative impact relating to disturbance, particularly on Ramsar site, the project proponent team explained that it was outside the works area of this EIA but the implications would be assessed in greater details in the SWC project.

Loss of egretry at Ngau Hom Shek

11. Members were concerned that no compensation was provided for the loss of breeding habitat for herons and egrets at Ngau Hom Shek during the construction stage of the project. The project proponent pointed out that the loss of the Ngau Hom Shek egretry was considered minor in territory-wide terms because of the small number of nests involved and the mobility of the Ngau Hom Shek egretry. Alternative nesting locations would also be available in nearby areas.

Loss of fishpond

12. Members were also concerned that during the construction stage no compensation was provided for the temporary loss of 0.73 ha of fishponds that acted as feeding ground for birds. The project proponent as well as AFCD officers pointed out that based on information available, the two affected fishponds had very low ecological value and one of them was an abandoned and dried up fishpond. The major species identified near the area of the two fishponds were a few Chinese Pond Heron and Little Egret which were tolerant to disturbance. Alternative feeding locations would also be available in nearby areas. Therefore, compensation during the construction phase was not necessary. Compensation in the long term would be provided nevertheless. Individual Members had doubt about the approach.

Residual construction noise impact

13. Members expressed concern about residual noise impact of 4 dB expected at six dwellings at Tsoi Yuen Tsuen for a period of about five weeks during construction phase. They noted that under existing guidelines, the six dwellings would not be qualified for the provision of air-conditioning.

Visual impact of noise barriers during operational stage

14. Members commented that the project proponent should avoid using bright and conspicuous colour scheme for noise barriers such as that adopted for the noise barriers in Tolo Highway.

Planting of native species of trees

15. Noting that about 6,500 trees would be planted as compensation measures, Members suggested that native species of trees should be given higher priority.


16. After detailed discussion, the Subcommittee concluded that it would recommend the EIA report to the Council for endorsement with the following proposed conditions-

  1. the project proponent should not commence work until the EIA report of the SWC project is endorsed by the Council;
  2. the project proponent should provide on-site or off-site compensation for the loss of 0.73 ha of fishpond during the construction stage or advance the section of work near pond no. 24 ahead of other sections so that the proposed fishpond could be created earlier to provide compensation;
  3. the project proponent should ensure that the functions of the recreated wetland adjacent to pond no. 24 are maintained all year round;
  4. the project proponent should consider providing alternative accommodation during the impact period for the residents of the six dwellings which are subject to residual noise impact;
  5. the project proponent should transplant mature trees, minimize the number of trees to be felled, and select native species of trees for planting;
  6. the project proponent should avoid using bright and conspicuous colour scheme for noise barriers such as that adopted for noise barriers in the Tolo Highway;
  7. the Habitat Management Plan should be approved by the authority before implementation; and
  8. the project proponent should provide data on background air pollutant concentrations and the concentrations after the completion of the project as generated from the modeling for the EIA Subcommittee's reference.

EIA Subcommittee Secretariat
August 2002




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