Introduction
4.1
The
EIAO-TM (Annex 16) requires that mitigation of ecological impacts be sought in
the following order of priority: (1) avoid, (2) minimise, (3) compensate
on-site and (4) compensate off-site. At
each stage, residual impacts should be re-assessed to determine whether there
is a need to proceed to the next stage of mitigation.
4.2
The EIA
Report identified some plant species of conservation interest being very common
on the site. The key ecological issue
would be related to the excavation works of Nam Long Shan (The Headland Area)
during the construction stage. Other
potential sources of ecological impact would comprise disturbance impact to the fauna associated with the
tall shrubland habitat.
With the implementation of recommended
mitigation measures, the construction works would not be expected to result in
unacceptable impacts on ecological sensitive receivers.
Monitoring Requirement
4.3
In order
to ensure that terrestrial ecological resources are adequately protected, the
implementation of all mitigation measures shall be subject to regular site
audit. In addition, the plant species of conservation interest affected by the proposed works
shall be monitored by qualified botanist / horticulturalist following
transplantation.
Baseline Review
4.4
A
qualified botanist/ecologist as a member of ET should review the detailed
design of the development in avoiding the plant species of conservation
interest. A detailed vegetation survey
of the affected plants of conservation interest shall be conducted prior to the
commencement of construction to identify the affected individuals in order to
provide details for transplantation scheme.
Construction Phase
4.5
A suitably
qualified botanist/horticulturalist as a member of ET shall supervise the
transplantation work in accordance with the formulated transplantation
methodology and conduct subsequent monitoring.
The health and condition of individuals of the transplanted plant
species of conservation interest shall monitored during the first 12 months
after transplantation. Monitoring
shall cover the 12-month period following transplantation, and be conducted at
least once a month.
4.6
Routine
site inspection shall be conducted on a weekly basis to review monitor and
audit the mitigation measures on disturbance on habitats adjacent to the work areas.
Mitigation Measures
4.7
The
mitigation measures recommended in the EIA Report include:
Design Phase
· Avoid impact to the plant species of conservation interest where possible during detailed design
· Avoid impact to potential nest sites in the tall shrubland habitat at Tai Shue Wan Area where possible for the design of conveyor belt system and the location of tunnel
· Avoid direct impact to nesting activities of Black Kites by scheduling site clearance works in the Headland Area before the breeding season of Black Kite.
· Avoid the filling of existing man-made ponds as far as practicable to avoid disturbance of the roosting site of birds such as Black-crowned Pond Heron
· The proposed underground or elevated new access road and funicular train at the Headland area to minimise impacts to natural terrain
· A detailed transplantation methodology shall be formulated during the detailed design stage for this Project
Construction Phase
· All excavation works carried out close to water bodies shall be carefully controlled to avoid runoff entering watercourses, especially during periods of heavy rain.
· Site runoff shall be directed towards regularly cleaned and maintained silt traps and where appropriate, oil/grease separators to minimise risk of sedimentation and pollution
· Suitable size / capacity silt traps and oil/grease interceptors shall be used.
· Noise mitigation measures including the use of quiet construction plant and movable noise barriers shall be implemented to minimise disturbance to habitats adjacent to the work areas
· Vegetation survey and subsequent transplantation of locally uncommon or restricted species shall be carried out to determine the feasibility and suitability of individual plants for transplantation. Receptor sites shall be identified. Transplantation shall be supervised by a suitably qualified botanist/ horticulturist.
· A detailed transplantation methodology shall be formulated during the detailed design stage based on the information collected during the detailed vegetation survey.
· Trees located within the works areas shall be preserved as far as practicable.
· A tree survey shall be conducted to identify any mature trees affected by the proposed works. If tree felling is unavoidable, feasibility of tree transplantation shall be explored and compensatory planting shall be provided on at least a 1:1 ratio.
· The loss of 4.8ha tall shrubland habitat will be compensated by planting native tall shrubs to enhance the ecological value of an existing low shrubland area with relatively low species diversity located to the north of Nam Long Shan Road close to the affected area. The identified area for compensation is approximately 6ha as shown in the EIA report
· Transplant as many affected individual plants of conservation interest as practical to suitable nearby habitats prior to the construction phase
· Placement of equipment or stockpile in designated works areas and access routes selected on existing disturbed land to minimise disturbance to natural habitats
· Construction activities shall be restricted to the work areas that would be clearly demarcated
· The work areas shall be reinstated immediately after completion of the works
· Waste skips shall be provided to collect general refuse and construction wastes. The wastes would be disposed of timely and properly off-site
· Drainage arrangements shall include sediment traps to collect and control construction run-off
· Open burning on works sites is illegal, and shall be strictly enforced
· Landscaping works on newly formed land shall as far as possible make use of native plant species
Operational Phase
No substantial increases in direct or indirect ecological impacts are expected and ecological monitoring will not be required.
4.8
The
implementation for the recommended ecological impact mitigation measures is
presented in Appendix B.
Introduction
4.9
Loss
of marine ecological resources is avoided as there would not be any
marine-based construction works for this Project. Potential source of marine ecological impact would be the
construction phase activities, such as site run-off and drainage. Nineteen species of hard corals and nine species
of octocorals were recorded during the surveys for the Project. Patchy distributions of some hard coral
species were observed but they are predominantly small in size (<10cm) and
most of them are common species. The
subtidal habitats were considered to be of moderate ecological value.
4.10
With the implementation of
mitigation measures for water quality impact, it was concluded that adverse
impact on coral communities would not be expected during the construction and
operation phase of the Project. Nevertheless,
coral monitoring is proposed during construction phase as a precautionary
measure. The coral monitoring programme
would focus on the hard coral communities located in proximity to area with potential
construction phase site run-off. The objective of this monitoring is to
verify the EIA predictions that no adverse impacts have occurred. In the event that adverse impacts were
identified and were shown to be a
consequence of the works, monitoring would also allow for implementation of
appropriate remedial actions to reduce such impacts.
Monitoring Locations
4.11
In the
vicinity of the construction works area, locations close to the potentially
impact areas were identified. These
Impact Monitoring Sites (Site 1, Site 2, Site 3, Site 4, and Site 5) will
constitute the impact monitoring stations for this construction phase coral
monitoring programme. As described in
the EIA Report, surveys conducted in 2005 indicated these sites were found to
have low cover of mainly common corals.
4.12
In order
to identify background environmental perturbations during the monitoring that
are not associated with the Project, coral monitoring should also be conducted
at a Control Site (Site C). Based on
previous studies, corals were found in area near Round Island and Chung Hom
Kok. It is considered that this area is
a suitable coral monitoring control station, which is located at a sufficient
distance from the works areas where no water quality impact associated with
Project would be likely. The exact
location of control station is subject to the findings of Baseline Survey. The
recommended site and the reasons for selecting the preferred control site
should be submitted to AFCD for consideration and agreement. Comparison of
monitoring data from Impact Monitoring Sites and the Control Site would be used
to confirm the source of impacts.
4.13
The location of the 5
Coral Impact Monitoring Sites is shown in Figure
4.1.
Monitoring Requirement
4.14
The
construction phase coral monitoring programme should comprise a Baseline Survey
with coral tagging exercise and Impact Monitoring Surveys.
4.15
Coral
monitoring work should be conducted by a qualified marine biologist with
specialist knowledge of corals and sound experience at identifying corals in
the field. To ensure consistency, it is
recommended that the same coral specialist should be used on each dive
survey. The coral specialist should be
approved by AFCD prior to the commencement of the monitoring programme.
Baseline Survey / Coral Tagging Exercise
4.16 A baseline survey and coral tagging exercise at all 5 coral impact sites and control site should be conducted preferably no more than one month before commencement of construction works. Tagging of a minimum of 10 hard coral colonies at each coral monitoring site is considered appropriate. Corals should be tagged giving priority to the largest, undamaged colonies since damage to these colonies would be more evident compared to smaller colonies or corals with existing damage. Corals should also be selected for tagging based on the most suitable coral species and growth forms. As far as possible, tagging of hard coral species with tall polyps should be avoided due to their higher tolerance of sedimentation.
4.17 Coral colonies should be tagged using small brightly coloured (e.g. orange or green) stones marked with labelled tags. For each tagged coral, specific detailed information should be collected including location, size, depth and general condition of their immediate surroundings. Tagged coral colonies should also be identified to species level.
4.18 The health status of each tagged coral colony should be carefully recorded, including information on existing surface area with partial mortality and bleached area. For each tagged hard coral colony, sediment cover should be recorded including percentage cover, colouration, texture and approximate thickness of sediment on the colony itself and on adjacent hard substrate. Any contiguous patches of sediment cover >10% should be counted. The condition of each tagged coral colony should also be recorded by taking a photograph from an angle and distance that best represents the entire colony. The information of selected corals collected during the Baseline Survey should be submitted to AFCD for approval.
Impact Monitoring Surveys
4.19 Impact monitoring is required to determine whether impacts are occurring on tagged corals during the period of construction works. A particular focus of the Impact Monitoring is effects due to sedimentation.
4.20
For Impact
Monitoring Site 1, Site 2, Site 3, Site 4, and Control Site C, the corals should be monitored monthly during
the first 2 months of the construction works.
If there is no exceedance recorded, the monitoring frequency would be
adjusted to quarterly during the rest of the construction period.
4.21 With the implementation of good site practices, no adverse impact on coral communities due to sedimentation is expected, nevertheless, Impact Monitoring is stepped up in areas near the proposed construction discharge point as a precautionary measure. Coral monitoring at Impact Monitoring Site 5 should be conducted twice a month at first 3 months of the construction works with the potential to discharge surface run-off such as site formation, road works, drainage, sewerage and water works. The monitoring frequency would be changed to monthly for the next 3 months if no adverse effects were recorded. After that, the monitoring will be changed to quarterly until the end of construction works.
4.22 Dive surveys for impact monitoring should collect the same information for tagged corals as the baseline survey. Information gathered during each Impact Monitoring survey should include observations on the health status of corals and sediment cover. It should also include condition of the tagged corals surroundings as well as weather, sea and tidal conditions. Each tagged coral should be photographed for every monitoring maintaining the same aspect and orientation as photographs taken for the baseline survey as far as possible.
4.23
The results of the impact
monitoring surveys should be reviewed with reference to findings of the
Baseline Survey and the data from Control Site C collected during the Impact
Monitoring.
4.24
All tags
at the impact and control stations should be removed/retrieved after the
monitoring is completed.
Post-project Monitoring Surveys
4.25
Post-project Monitoring should
be conducted to confirm that is no adverse impact to the coral communities due
to the Project. Site 1, Site 2, Site 3,
Site 4, and Site 5 should be surveyed once within one month after the
completion of construction activities.
Compliance / Event Action Plan
4.26 Coral monitoring results should be evaluated against Action and Limit Levels. Evaluation should be based on recorded changes in
l Percentage of partial mortality
l Percentage of sediment cover
l Percentage of bleaching
4.27
Action and Limit Levels are defined in
Table 4.1.
Table 4.1 Action and
Limit Level for Coral Monitoring
|
Parameter |
Action
Level Definition |
Limit
Level Definition |
|
Sedimentation |
If during Impact Monitoring a 15% increase in
the percentage of sediment cover on hard corals occurs at more than 20% of
the tagged coral at any one Impact Monitoring Site that is not recorded at
the Control Site, then the Action Level is exceeded. |
If during the Impact Monitoring a 25%
increase in the percentage of sediment cover occurs at more than 20% of the
tagged coral at any one Impact Monitoring Site that is not recorded at the
Control Site, then the Limit Level is exceeded. |
|
Bleaching |
If during Impact Monitoring a 15% increase in
the percentage of bleaching (bleached white) on hard corals occurs at more
than 20% of the tagged coral at any one Impact Monitoring Site that is not
recorded at the Control Site, then the Action Level is exceeded. |
If during the Impact Monitoring a 25%
increase in the percentage of bleaching (bleached white) occurs at more than
20% of the tagged coral at any one Impact Monitoring Site that is not
recorded at the Control Site, then the Limit Level is exceeded. |
|
Mortality |
If during Impact Monitoring a 15% increase in
the percentage of partial mortality on hard corals occurs at more than 20% of
the tagged coral at any one Impact Monitoring Site that is not recorded at
the Control Site, then the Action Level is exceeded. |
If during the Impact Monitoring a 25%
increase in the percentage of partial mortality occurs at more than 20% of
the tagged coral at any one Impact Monitoring Site that is not recorded at
the Control Site, then the Limit Level is exceeded. |
4.28
If
the defined Action Level or Limit Levels for coral monitoring are exceeded, the
stepwise procedures set out in Table 4.2 should be implemented.
Table 4.2 Action and
Limit Level Exceedance Procedure for Coral Monitoring
|
Event |
ET
Leader |
|
Action
Level Exceedance |
Step
1 -
Inform the IEC, ER, Contractor, Project Proponent, EPD, and AFCD and discuss
the most appropriate method of reducing sediment in the discharge (e.g. check
and increase effectiveness of construction site drainage and
sediment and other site run-off removal facilities) Step
2 –
Audit the implementation of mitigation measures on site. Step 3 - If non-compliance continues, check and confirm
the effectiveness of mitigation measures and repeat monitoring survey
measurements. |
|
Limit
Level Exceedance |
Undertake Steps 1-3. If further exceedance of
Limit Level, suspend construction works until an effective solution is
identified. Once the solutions have
been identified and agreed with all parties, construction works may commence. |
Reporting
4.29
A baseline
survey report should be complied and certified by IEC and submitted to AFCD
prior to the commencement of construction works.
4.30
Coral
impact monitoring report should be submitted and certified by IEC and submitted
to AFCD within 2 weeks after the completion of each impact monitoring
surveys. Interpretation of coral
monitoring results should make reference to Baseline Survey results.
4.31
A
post-project monitoring report should be submitted and certified by IEC and
submitted to AFCD within 2 weeks after the completion of the post-project
monitoring surveys. Interpretation of
coral monitoring results should also make reference to Baseline Survey results.
Mitigation Measures
4.32
No adverse impact on coral
communities would be expected during the construction and operation phase of
the Project. And detailed mitigation measures related to water quality impacts
are discussed in Section 8.