EXECUTIVE SUMMARY
The Project “Landslide Preventive Works at Po Shan, Mid-levels – Design and
Construction (Natural Terrain Risk Mitigation Works)” (hereafter called “the
Project”) includes the installation of about 700 numbers of soil nails and
about 60 numbers of raking drains on the natural terrain within the concerned
area.
China State – China Railway Joint Venture (CCJV) was commissioned as the
Contractor of the Project. ENSR Asia (HK) Ltd. was employed by CCJV as the
Environmental Team to carry out the EM&A programme.
The impact environmental monitoring and audit for the Project includes the
air quality, noise, ecology, landscape and visual monitoring. The construction
of the Project and the EM&A programme commenced on 1 April 2008.
This report documented the findings of EM&A works conducted in the
period between 1 and 31 July 2008. As informed by the Contractor, construction
activity in the reporting period was:
-
Soil nail installation at Portion A1.
Breaches of Action and Limit
Levels
There was no action / limit level exceedance recorded for 1-hour and
24-hour TSP monitoring.
In the reporting month, all noise level recorded complied with the limit
level.
Complaint, Notification of
Summons and Successful Prosecution
There was no complaint, notification of summons and successful
prosecution received in the reporting month.
Reporting Change
There was no reporting change required in the reporting month.
Future Key Issues
The weather in the forthcoming month is expected to be wet and windy.
The Contractor should provide preventive measures to prevent any muddy runoff,
such as proper collection and treatment of the runoff and provide a functional
temporary drainage system in site.
It is also recommended to implement all necessary preventive measures to
avoid oil leakage on ground / soil, such as provision of drip trays for all oil
drums / chemical containers. In the event of oil leakage, the Contractor should
properly remove the contaminated soil and dispose of as chemical waste.
Construction waste and general refuse should be properly collected and disposed
of.
1.
INTRODUCTION
Background
1.1
The project site is located at the mostly
undeveloped hillside above the residential development at Po Shan Road and
adjacent to the trimmed back slope on the site of the catastrophic 1972 Po Shan
Road failure. Previous studies had been carried out and results indicated that
the natural hillside above Po Shan Road is affected by high groundwater level
and unfavourable geology. Sub-surface drainage measures by means of
sub-horizontal drains had been installed in 1984-85. These measures have been successful
in lowering the main ground water table, thus improving the stability of the
slopes such that large-scale failure have not occurred in the last twenty
years.
1.2
The objective of the Project “Landslide Preventive
Works at Po Shan, Mid-levels – Design and Construction (Natural Terrain Risk
Mitigation Works)” under Contract CE 28/2004 (GE) is to carry out detailed
design and supervision of landslide preventive works on local repair of the
hillside to minimize slope deterioration and shallow instability.
1.3
The proposed landslide preventive works would be
constructed to protect the existing residential developments at the toe of the
project site.
1.4
The scope of works of this Project includes the installation
about 700 numbers of soil nails and about 60 numbers of raking drains on the
natural terrain within the concerned area. The length of the soil nails is
about 20m with a spacing
of 2m horizontally and 3m vertically; the length of raking drains is about 10m with a spacing of 5m horizontally
and 15m vertically.
1.5
The Project is anticipated to complete in 10 months
after the commencement of construction.
1.6
According to the Environmental Permit
(EP-235/2005/B) and the EM&A Manual of the Project, there is a need of an
EM&A programme including air quality, noise, ecology, and landscape and
visual monitoring.
1.7
ENSR Asia (HK) Ltd. (ENSR) was employed by the
Contractor, China State – China Railway Joint Venture, as the Environmental
Team (ET) to undertake the Environmental Monitoring and Audit (EM&A) works
for the Project. In accordance with the EM&A Manual of the Project,
environmental monitoring of air quality, noise, ecology, landscape and visual
and environmental site inspections would be required for this Project.
Scope of Report
1.8
This is the fourth monthly Environmental Monitoring
and Audit (EM&A) Report under the Contract CE 28/2004 (GE) – Landslide
Preventive Works at Po Shan Road, Mid-Levels – Design and Construction (Natural
Terrain Risk Mitigation Works). This report presented a summary of the
environmental monitoring and audit works, list of activities, and mitigation
measures proposed by the ET for the Project in July 2008.
Project Organization
1.9
The project organization is
shown in Appendix A. The key personnel contact names and numbers are summarized
in Table 1.1
.
Table 1.1 Contact Information
of Key Personnel
|
Party
|
Position
|
Name
|
Telephone
|
Fax
|
|
CEDD
|
Senior Engineer
|
H. W. Sun
|
2762 5375
|
2714 0247
|
|
ER (MGS)
|
Resident Engineer
|
Andrew J. Westmoreland
|
3188 0400
|
3188 0775
|
|
Assistant Resident Engineer
|
S. F. Chau
|
3188 0400
|
3188 0775
|
|
IEC
(ENVIRON)
|
Independent
Environmental Checker
|
David
Yeung
|
3743
0788
|
3548
6988
|
|
Contractor
(CCJV)
|
Project
Manager
|
Eddie
Tang
|
3188
0538
|
3188
1710
|
|
Safety
and Environmental Officer
|
Ken
Fong
|
3188
0538
|
3188
1710
|
|
ET
(ENSR)
|
ET
Leader
|
Alex
Chan
|
3105
8525
|
2891
0305
|
Summary of Construction Works
1.10
The Contactor has carried
out major activities in the reporting month. Details of the works undertaken in
this reporting period are listed below:
-
Soil nail installation at Portion A1.
1.11
The general layout plan of the
Project site showing the contract area is shown in Figure 1.1. The construction
programme is provided in Appendix B.
1.12
The mitigation measures
implementation schedule are presented in Appendix C.
Summary of EM&A Programme
Requirements
1.13
The EM&A programme
required environmental monitoring for air quality, noise, ecology and landscape
and visual and environmental site inspections for air quality, noise, ecology,
landscape and visual and waste management. The EM&A requirements for each
parameter described in the following sections include:
-
All monitoring parameters;
-
Monitoring schedules for
the reporting month and forthcoming months;
-
Action and Limit levels for
all environmental parameters;
-
Event / Action Plan;
-
Environmental mitigation measures,
as recommended in the Project EIA study final report; and
-
Environmental requirement
in contract documents.
2.
AIR QUALITY
Monitoring Requirements
2.1
In accordance with the EM&A Manual, 1-hour and 24-hour
TSP levels at 2 air quality monitoring stations were established. Impact 1-hour
and 24-hour TSP monitoring was conducted for at least once every 7 days during
the construction phase of the Project. The Action and Limit level of the air
quality monitoring is provided in Appendix D.
Monitoring Equipment
2.2
24-hour TSP air quality monitoring was performed
using High Volume Sampler (HVS) located at each designated monitoring station.
The HVS meets all the requirements of the EM&A Manual. Portable direct reading
dust meters were used to carry out the 1-hour TSP monitoring. Table 2.1
summarises the equipment used.
Table 2.1 Air Quality
Monitoring Equipment
|
Equipment
|
Model
|
|
High
Volume Sampler
|
GS
2310 Accu-vol system
|
|
Calibrator
|
GMW 25
|
|
1-hour
TSP Dust Meter
|
Laser
Dust Monitor – Model LD-3
|
Monitoring Parameters, Frequency and Duration
2.3
Table 2.2 summarizes the monitoring parameters,
frequency and duration of impact TSP monitoring.
Table 2.2 Air Quality Monitoring Parameters, Frequency and Duration
|
Monitoring Station
|
Parameter
|
Frequency and Duration
|
|
CA1 & CA2
|
|
At least once every 7 days
|
|
1-hour TSP
|
At least 3 times every 7 days
|
Monitoring Locations
2.4
Both monitoring stations were set up at the
proposed locations in accordance with EM&A Manual. Table 2.3 describes
details of the two monitoring stations. The monitoring locations are shown in
Figure 2.1.
Table 2.3 Locations of Air Quality
Monitoring Stations
|
Monitoring Station
|
Identity / Description
|
|
CA1
|
Access
road to Po Shan Mansions
|
|
CA2
|
Podium
of Hamilton Court
|
Monitoring Methodology
24-hour TSP Monitoring
Installation
2.5
The HVS was installed in the vicinity of the air
sensitive receivers. The following
criteria were considered in the installation of the HVS.
·
A horizontal platform with appropriate support to
secure the sampler against gusty wind was provided.
·
The distance between the HVS and any obstacles,
such as buildings, was at least twice the height that the obstacle protrudes
above the HVS.
·
A minimum of 2 meters separation from walls,
parapets and penthouse was required for rooftop sampler.
·
No furnace or incinerator flues were nearby.
·
Airflow around the sampler was unrestricted.
·
Permission was obtained to set up the samplers and
to obtain access to the monitoring stations.
·
A secured supply of electricity is needed to
operate the samplers.
Preparation of Filter Papers
·
Glass fibre filters, G810 were labeled and sufficient filters that were
clean and without pinholes were selected.
·
All filters were equilibrated in the conditioning environment for 24
hours before weighing. The conditioning environment
temperature was around 25 °C and not variable by more than ±3 °C; the relative humidity (RH) was
< 50% and not variable by more than ±5%.
A convenient working RH was 40%.
·
ALS Technichem (HK) Pty Ltd. has comprehensive quality
assurance and quality control programmes.
Field Monitoring
·
The power supply was checked to ensure the HVS works properly.
·
The filter holder and the area surrounding the filter were cleaned.
·
The filter holder was removed by loosening the four bolts and a new
filter, with stamped number upward, on a supporting screen was aligned
carefully.
·
The filter was properly aligned on the screen so that the gasket formed
an airtight seal on the outer edges of the filter.
·
The swing bolts were fastened to hold the filter holder down to the
frame. The pressure applied should be
sufficient to avoid air leakage at the edges.
·
Then the shelter lid was closed and was secured with the aluminum strip.
·
The HVS was warmed-up for about 5 minutes to establish run-temperature
conditions.
·
A new flowrate record sheet was set into the flow recorder.
·
The range specified in the EM&A Manual was between 0.6-1.7
m3/min.
·
The programmable timer was set for a sampling period of 24 hrs +
1 hr, and the starting time, weather condition and the filter number were recorded.
·
The initial elapsed time was recorded.
·
At the end of sampling, the sampled filter was removed carefully and
folded in half length so that only surfaces with collected particulate matter
were in contact.
·
It was then placed in a clean plastic envelope and sealed.
·
All monitoring information was recorded on a
standard data sheet.
·
Filters were sent to ALS Technichem (HK) Pty Ltd. for
analysis.
Maintenance and Calibration
·
The HVS and its accessories are maintained in good working condition,
such as replacing motor brushes routinely and checking electrical wiring to
ensure a continuous power supply.
·
HVSs are calibrated using GMW-25 Calibration Kit prior to the
commencement of baseline air quality monitoring, and will be calibrated at
bi-monthly intervals throughout all stages of the impact monitoring.
·
Calibration records are shown in Appendix E.
1-hour TSP Monitoring
Measuring Procedures
2.6
The measuring procedures of the 1-hour dust meter
are in accordance with the Manufacturer’s Instruction Manual as follows:
·
Set POWER to “ON”, push BATTERY button, make sure that the meter’s
indicator is in the range with a red line and allow the instrument to stand for
about 3 minutes (Then, the air sampling inlet has been capped).
·
Push the knob at MEASURE position.
·
Push “O-ADJ” button. (Then meter’s indication is 0).
·
Push the knob at SENSI ADJ position and set the meter’s indication to S
value described on the Test Report using the trimmer for SENSI ADJ.
·
Pull out the knob and return it to MEASURE position.
·
Push “START” button.
Maintenance and Calibration
·
The 1-hour TSP meter would be checked at 3-month intervals and
calibrated at 1-year intervals throughout all stages of the air quality
baseline monitoring. Calibration records are shown in Appendix E.
Monitoring Results
2.7
The monitoring results for 1-hour TSP and 24-hour TSP
are summarized in Table 2.4 and 2.5 respectively and the monitoring results are
provided in Appendix F.
Table 2.4 Summary of 1-hour TSP Monitoring Results in the Reporting
Period
|
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
|
CA1
|
70.8
|
59.0 – 80.2
|
309.3
|
500
|
|
CA2
|
69.5
|
56.7 – 80.6
|
319.6
|
500
|
Table 2.5 Summary of 24-hour TSP Monitoring Results in the Reporting
Period
|
|
Average (mg/m3)
|
Range (mg/m3)
|
Action Level (mg/m3)
|
Limit Level (mg/m3)
|
|
CA1
|
34.8
|
24.0 – 61.2
|
166.8
|
260
|
|
CA2
|
23.1
|
9.4 – 52.7
|
187.0
|
260
|
2.8
Air quality monitoring was
carried out for both 1-hour TSP and 24-hour TSP at all the monitoring stations
in the reporting month.
2.9
The air quality monitoring results, in terms of
1-hour TSP and 24-hour TSP, were below the action and limit level at both
monitoring locations in the reporting month. The event action plan is annexed
in Appendix G.
2.10
Weather information including wind speed and wind
direction is annexed in Appendix H. The information was obtained from Hong Kong
Observatory Victoria Peak Automatic Weather Station and Central Pier Anemometer
Station.
3.
NOISE
MONITORING
Monitoring
Requirements
3.1
In accordance with the EM&A Manual, impact noise levels should be
obtained at 2 noise monitoring stations. Impact noise monitoring was conducted
for at least once per week during the construction phase of the Project. The
Action and Limit level of the noise monitoring is provided in Appendix D.
Monitoring Equipment
3.2
Integrating Sound Level Meter was employed for noise monitoring. They were Type 1 sound level meters capable
of giving a continuous readout of the noise level readings including equivalent
continuous sound pressure level (Leq) and percentile sound pressure
level (Lx). They comply with International Electrotechnical Commission
Publications 651:1979 (Type 1) and 804:1985 (Type 1). Portable electronic wind speed indicator capable
of measuring wind speed in m/s was employed to check the wind speed. Table 3.1 details the noise monitoring
equipment used.
Table 3.1 Noise Monitoring
Equipment
|
Equipment
|
Model
|
|
Integrating Sound Level Meter
|
Rion NL-31
|
|
Calibrator
|
Rion NC-73
|
Monitoring Locations
3.3
Two monitoring stations were set up in accordance
with EM&A Manual. Table 3.2 describes details of the two monitoring
stations. The monitoring locations are shown in Figure 2.1.
Table
3.2 Locations of Noise Monitoring Stations
|
Monitoring Station
|
Identity / Description
|
|
CN1
|
Block A, Po Shan Mansions
|
|
CN2
|
Block A, Po Shan Mansions
|
Monitoring Parameters
3.4
One set of 30-mins measurement at each monitoring station between 0700 and
1900 on normal weekdays at a frequency of once per week was required to
determine the impact noise level. Leq, L10 and L90
would be recorded.
Monitoring Methodology
Monitoring Procedures
·
The Sound Level Meter was set on a tripod at a
height of 1.2 m above the ground.
·
Façade measurements were made at all three
monitoring locations.
·
The battery condition was checked to ensure the
correct functioning of the meter.
·
Parameters such as frequency weighting, the time
weighting and the measurement time were set as follows:
-
frequency weighting: A
-
time weighting: Fast
-
time measurement: Leq(30 minutes) during
non-restricted hours i.e. between 07:00 and 19:00 on normal weekdays
·
Prior to and after each noise measurement, the meter
was calibrated using a Calibrator for 94 dB at 1000 Hz. If the difference in the calibration level
before and after measurement was more than 1 dB(A), the measurement would be
considered invalid and repeat of noise measurement would be required after
re-calibration or repair of the equipment.
·
The wind speed was frequently checked with a
portable wind meter.
·
During the monitoring period, the Leq ,
L10 and L90 were recorded. In addition, site conditions and noise
sources were recorded on a standard record sheet.
·
Noise measurement was paused during periods of high
intrusive noise (e.g. dog barking, helicopter noise) if possible. Observations
were recorded when intrusive noise was unavoidable.
·
Noise monitoring was cancelled in the presence of
fog, rain, wind with a steady speed exceeding 5 m/s, or wind with gusts exceeding 10 m/s.
Maintenance and Calibration
·
The microphone head of the sound level meter and
calibrator is cleaned with soft cloth at quarterly intervals.
·
The meter should be checked and calibrated at yearly intervals.
·
Calibration details for the sound level meter and calibrator are
provided in Appendix E.
Monitoring Results
3.5
The monitoring results for noise are summarized in
Table 3.3 and the monitoring data is provided in Appendix I.
Table
3.3 Summary of Noise Monitoring
Results in the Reporting Period
|
|
Average, dB(A), Leq (30 mins)
|
Range, dB(A), Leq (30 mins)
|
Limit Level, dB(A), Leq (30 mins)
|
|
CN1
|
60.7
|
58.6 – 61.9
|
75.0
|
|
CN2
|
59.5
|
56.9 – 61.1
|
75.0
|
3.6
There was no noise complaint received in the reporting month, hence, no
action level exceedance was recorded. At both monitoring locations, CN1 and
CN2, all the monitoring results (daytime) were below the limit level of 75
dB(A).
3.7
All the monitoring results lied within the range of the predicted noise
levels in the EIA report.
3.8
Major noise sources during the noise monitoring included the
construction activities from the Project and another project under the same contract
(concurrent project) carried out in the vicinity and nearby traffic noise.
4.
VEGETATION
MONITORING
Monitoring Requirement
4.1
As required under Environmental Permit No. EP-235/2005/B, the Permit Holder
is required to carry out monitoring of the plant species of conservation
interest to check on the health and condition of the plants twice a month
during the construction period of the Project.
4.2
It is required to undertake the ecological tasks to fulfill the
requirements of the Environmental Permit (EP).
As required by Conditions 2.11 and 3.5 of the EP, a suitably qualified ecologist with 7 or more years
of relevant experience shall be employed to conduct the ecological monitoring.
Monitoring Location
4.3
The ecological monitoring was carried out for plant individuals of
conservation interest identified within the proposed works area.
Monitoring
Methodology
4.4
The ecological monitoring was conducted twice in the reporting month on
22 and 29 July 2008 by Ms. Gigi C C Lam, who had over 7 years of relevant
ecological experience.
4.5
The plants of conservation interest, which were tagged during the
baseline survey, were checked during each monitoring.
Monitoring Results
4.6
Soil nailing scaffolding works were in progress during the monitoring
visits. A total of 13 plant species of
conservation interest (i.e. V001 to V013) were identified within the above
works area during an earlier Detailed Vegetation Survey conducted under this
Project. The tagged vegetation was found
to be in good condition during the monitoring visits in July 2008.
4.7
Construction materials such as planks, sand bags, metal rods were found to
be placed over or near the lower trunks of some trees in Row C, L, O and
R. It was recommended that these
materials should be kept in proper place to avoid damage to vegetation within
works area.
4.8
Concrete was found to be spilled over from the soil nailing works zones
onto nearby areas. It was recommended
that the concrete should be removed from the soil surface. The Contractor advised that the concrete will
be removed and measures will be implemented to avoid any further spillage.
4.9
The leaves, branches and trunk of a tree (Machilus sp.) located in Row O was found to be covered with sand
and mud probably generated from nearby soil nailing works.
4.10
Two trees, Celtis sinensis and
Machilus sp., located near the
conveyor belt and above Row Q were found to be dead and in very poor condition
respectively. A dead tree (tree tag
number T238) was collapsed within works area.
It was recommended that all dead trees found within the construction
site should be recorded and reported to relevant departments without
delay.
4.11
Two main roots of a big tree (Acacia
confusa of tree tag number T247) were cut due to the construction of soil
nail number I6 (Figure 4.1).
4.12
The trunk of a tree (tree tag number T344) located next to a soil nailing
area in Row O was covered with concrete.
5. LANDSCAPE AND
VISUAL
Monitoring Requirement
5.1
During the construction
phase of the Project, landscape and visual monitoring should be carried out
bi-weekly by a Registered Landscape Architect (RLA) to check if the design,
implementation and maintenance of the landscape and visual mitigation measures
are fully realized. A detailed report is annexed in Appendix J.
Summary of Inspection – 2 July 2008
Matters Arising from Previous Inspections
5.2
The Contractor had removed
all metal pipes / steel bars previously stockpiled / stacked against the
existing tree trunks at various locations on site, except for one
location. The Contractor was reminded to
urgently remove it as soon as possible.
5.3
It was still noted that no
tree protection with wooden slats was made for trees enclosed within the
drilling platforms. The Contractor was
reminded to provide adequate tree protection works near the trees in order to
prevent accidentally damaging the trees.
Protection of Existing Trees
5.4
Construction equipments
were observed being placed against the tree trunks of existing trees at several
locations on site. The Contractor was requested
to clear the equipment and not to place it against trees in future in order to
prevent damage to the trees.
5.5
Also, soil bags were
observed placed on slopes and rested at the base of the tree trunks. The Contractor was requested to clear to soil
bags away from the base of the tree as soon as possible.
5.6
Construction waste pile was
observed on the slope. The Contractor
was requested to clear it away as soon as possible.
Recommendations
5.7
The Contractor was recommended
to provide more protection to existing trees which are enclosed within the
drilling platforms in order to prevent the tree from being damaged.
5.8
The Contractor was
recommended to keep all construction materials and equipments away from
existing trees and not to place them against the trees in future.
Summary
of Inspection – 15 July 2008
Matters Arising from Previous Inspections
5.9
The Contractor had removed
all metal pipes previously stockpiled / stacked against the existing tree
trunks on site.
5.10
The Contractor had cleared
the construction equipments previously observed placed against the tree trunks
of existing trees.
5.11
Clearance of soil bags
previously observed being placed on slopes and rested at the base of the tree trunks
was still outstanding. The Contractor
was reminded to clear it away as soon as possible.
5.12
Clearance of the
construction waste pile previously observed on the slope was still
outstanding. The Contractor was reminded
to clear it away as soon as possible.
Protection of Existing Trees
5.13
Scaffolding metal pipes
were found with some being rested on and others being rested against existing
trees. The Contractor was requested to
remove the pipes away from the trees as soon as possible.
Recommendations
5.14
The Contractor was
recommended to provide more protection to existing trees which are enclosed
within the drilling platforms in order to prevent the tree from being damaged.
5.15
The Contractor was recommended
to keep all construction materials and equipments away from existing trees and
not to place them against the trees in future.
5.16
The Contractor was reminded
to clear the construction waste pile as found on the slope and keep the site in
a tidy condition.
Summary
of Inspection – 29 July 2008
Matters Arising from Previous Inspections
5.17
The Contractor had cleared
away the construction waste pile previously observed on the slope.
5.18
The Contractor had cleared the
scaffolding metal pipes away from existing trees.
5.19
Clearance of soil bags
previously observed being placed on slopes and rested at the base of the tree
trunks was still outstanding. The
Contractor was again reminded to clear it away as soon as possible.
Protection of Existing Trees
5.20
Existing tree T238 was
found dead with rotten tree trunk at the base.
The Contractor was requested to remove the tree for safety as soon as
possible.
5.21
It was observed that the Contractor
had cut several large roots (up to 100mm diameter) of the existing large tree
T247 while carried out the excavation for the soil nail head. The Contractor was warned that the practice
was unacceptable and large tree root shall not be cut without prior inspection
and agreement with the Engineer. The
Contractor was requested to apply protective sealant to prevent the roots from
rotting.
5.22
It was again observed that
the Contractor had tied overhead plastic sheeting to existing tree trunks. The Contractor was requested to remove the
ties to prevent damage to the trees.
5.23
It was observed that the
soil nail drilling had allowed the extracted materials fines being sprayed onto
several tree trunks (i.e. T342). The Contractor
was requested to clean up the tree trunks and to provide protection to the tree
trunks in future.
Recommendations
5.24
The Contractor was
recommended to keep all soil bags away from existing trees and not to place
them against the trees in future.
5.25
The Contractor was
recommended to apply root protective sealant to the wounded roots. The Contractor was recommended to seek the
Engineer’s agreement for excavation works near existing tree roots in order to
minimize damage to the tree root system.
If root pruning is required, prior approval from Engineer is required.
5.26
The Contractor was
recommended to clean the material fines off the tree trunks and to provide tree
protection in future when carried out drilling works.
Next
Landscape and Visual Audit Schedule
5.27
The landscape and visual audits in the next reporting month was tentatively
scheduled to 12 and 26 August 2008.
6.
ENVIRONMENTAL SITE INSPECTION
AND AUDIT
Site Inspection
6.1
Site Inspections were carried
out on a weekly basis to monitor the implementation of proper environmental
pollution control and mitigation measures for the Project. In the reporting
month, 5 site inspections were carried out on 2, 8, 15, 22 and 29 July 2008.
The detail findings of the landscape and visual audits in the reporting month
are presented separately in Section 5. The environmental site inspection
summaries are attached in Appendix K. Particular observations are described
below.
Air Quality
6.2
No adverse observation was identified
in the reporting month.
Noise
6.3
No adverse observation was
identified in the reporting month.
Water Quality
6.4
Debris and leaves were observed inside the
u-channel near Row R and Row S. The Contractor was reminded to clear the u-channel
more frequently.
6.5
Minor muddy water was observed running down the
u-channel near Row K and Row M. The Contractor was reminded to clear the
exposed earth at all working platforms and properly maintain the desilting tank
next to Row D.
Chemical and Waste Management
6.6
Oil drums and soil nail installation controller
were found placed on ground without drip tray at Row Q, Row R and Row S. The
Contractor was reminded to provide drip trays to the chemical containers and
all plants on site.
Ecology
6.7
Sand bags and C&D materials were observed
placed against the trees at Row C, Row D, Row E and Row R. The Contractor was
reminded to keep the C&D materials away from the trees.
6.8
Construction materials
placed near tree trunks and spillage of concrete near soil nailing areas were
observed. Some of the plants were not
properly protected during soil nailing works and serious damages to root
systems were recorded. One recently dead
tree was found within the works area.
Landscape and Visual
6.9
The Contractor was
recommended to provide more protection to existing trees which are surrounded by
drilling platforms and avoid stockpiling of any construction materials /
equipments / sand bags against or near existing trees.
5.28
The Contractor was
recommended to apply root protective sealant to the wounded roots. The Contractor was recommended to seek the
Engineer’s agreement for excavation works near existing tree roots in order to
minimize damage to the tree root system.
If root pruning is required, prior approval from Engineer is required.
5.29
The Contractor was
recommended to clean the material fines off the tree trunks and to provide tree
protection in future when carried out drilling works.
Assessment of Environmental Monitoring Results
6.10
All monitoring results were
audited against the Action / Limit levels and any exceedance would be validated
and issued when necessary.
6.11
The monitoring results in
the reporting period were comparable with the EIA predictions. Detailed discussions
are given in Section 2 and 3.
Advice on the Solid and Liquid Waste Management
Status
6.12
The Contractor is
registered as a chemical waste producer for this Project. The Chemical Waste
Storage Area located at the Contractor’s site office area was properly
maintained in the reporting month.
6.13
No waste disposal was made
in the reporting month. Most of the C&D waste generated was reused on site.
Environmental Licenses and Permits
6.14
The environmental licenses and
permits for this Project and valid in the reporting month is summarized in
Table 6.1.
Table 6.1 Summary of
Environmental Licensing and Permit Status
|
Description
|
Permit No.
|
Valid Period
|
Remarks
|
|
From
|
To
|
|
Environmental Permit
|
EP-235/2005/B
|
23/11/07
|
--
|
-
Installation of about 700
nos. of soil nails and about 60 nos. of raking drains in the natural terrain;
-
Rock slope stabilisation
works at upper portion of the natural terrain; and
-
Other associated works.
|
|
Registration as a Chemical Waste Producer
|
5213-141-C3250-02
|
13/12/06
|
--
|
Spent lubricating oil and mineral oil
|
|
Effluent Discharge License
|
EP880/W10/XX0261
|
07/11/06
|
31/12/11
|
--
|
|
Notification of Constriction Work under APCO (Construction Dust)
|
001012125
|
18/07/06
|
--
|
--
|
Implementation Status of Environmental
Mitigation Measures
6.15
In response to the site
audit findings, the Contractor carried out corrective actions.
6.16
A summary of the Implementation
Schedule of Mitigation Measures (EMIS) is presented in Appendix C. Most of the
necessary mitigation measures were implemented properly.
Summary of Exceedances of the Environmental
Quality Performance Limit
6.17
All 1-hour TSP, 24-hour TSP
and noise monitoring results complied with the Action / Limit levels.
6.18
No exceedance was recorded
in the reporting month.
Summary of Complaints, Notification of Summons
and Successful Prosecutions
6.19
The Environmental Complaint
Handling Procedure is annexed in Figure 6.1.
6.20
No environmental complaint, notification of summons
and successful prosecutions was received in the reporting month.
7.
FUTURE
KEY ISSUES
Construction Programme for the Coming Months
7.1
The construction programme for
the Project is provided in Appendix B.
7.2
The major construction work
in August 2008 will be:
-
Soil Nail installaton at Portion A1,
Portion A2 and Portion B1.
Key Issues for Coming Month
7.3
Key issues to be considered
in the coming month included:
-
Properly store and label
oils and chemicals on site;
-
Collection of construction
waste should be carried out regularly;
-
Site runoff should be
properly collected and treated prior to discharge;
-
Construction activities
should avoid causing damage to the trees and to plants species of conservation
interest;
-
Quieter powered mechanical
equipment should be used.
7.4
The following mitigation
measures are required:
Air Quality Impact
-
Regular watering should be
used during soil nailing;
-
Dusty material stockpiled should
be completely covered;
-
Dusty activities should be
re-scheduled if high-wind conditions encountered;
-
Open burning should be
strictly prohibited;
-
All dusty vehicle loads
transporting to, from and between site locations should be covered with
tarpaulin;
-
Vehicle wheel and body
washing facilities should be used at all exit points of the site;
-
Wind shield, dust
extraction units or water spraying should be used at the loading points.
Construction Noise Impact
-
Quieter powered mechanical equipment
should be used;
-
Insulating fabric should be
used for drill rigs during drilling process;
-
Noise generating
construction works should be carried out during daytime only;
-
Noise barriers or other
measures should be used to minimize disturbance to the bat roost;
-
Plant on site should be
properly maintained and serviced regularly;
-
Mobile plants should be
sited as far from NSRs as possible;
-
Machines and plant in
intermittent use should be throttled down;
-
Strong noise emitting
plants, wherever possible, should be oriented so that noise is directed away
from the nearby NSRs;
-
Material stockpiles,
wherever possible, should be effectively utilized to screen noise from
construction activities;
-
Movable noise barrier with
surface mass in excess of 7kg/m2 should be used for PME wherever
possible;
-
Noise insulating fabric
should be adopted for drill rig operating in Works Area E.
Water Quality Impact
-
Prevent runoff water from
entering the nearby water-bodies;
-
Silt traps and oil / grease
separators should be regularly cleaned and maintained;
-
Outlet pipe extending above
the slope surface should be installed;
-
Air should be used as the
flushing medium of the drilling equipment;
-
Earth bunds or sand bag barriers
should be provided on-site to direct storm water to silt removal facilities;
-
Exposed slope / soil
surface and opened stockpile of more than 50m3 should be covered
with tarpaulin;
-
Oils and fuels should be
used and stored in designated area.
Chemical and Waste
Management
-
Debris and rubbish on-site
should be collected, handled and disposed of properly;
-
Waste skips should be
provided to collect general refuse and construction wastes;
-
Soil contamination with
fuel leaked from construction plants should be removed off-site;
-
Sufficient waste disposal
points with regular collection should be provided;
-
Appropriate measures should
be provided to minimize windblown litter and dust during transportation of
waste;
-
Different containers should
be used to segregate and store different types of waste;
-
Encourage collection of
aluminum cans, PET bottles and paper by providing separate bins;
-
Unused chemicals should be
recycles wherever possible;
-
Proper storage and site
practices should be adopted to minimize the potential for damage and
contamination of construction materials;
-
Oils and fuels should be
stored in designated area;
-
Plan and stock construction
materials carefully to minimize waste generation.
Ecological Impact
-
Soil nail installation should
avoid / minimize damage of root system to the existing plants;
-
Fences should be erected
along the boundary of the works area
-
Disturbance to the natural
woodland and shrubland habitats should be minimized by preventing tipping,
vehicle movements and encroachment of personnel onto the adjacent area;
-
Permanent casing should be
provided to the drillhole of soil nail;
-
Placement of equipment or
stockpile should be located in designated areas to minimize disturbance to
natural or moderate-high ecological value habitats;
-
Construction activities
should be restricted to works areas;
-
Disturbance to existing
vegetation should be minimized wherever possible.
Landscape and Visual Impact
-
Designation of
“no-intrusion zones” and record any trespass and damage to existing vegetation;
-
Soil nails on site should
avoid tree trunks and tree roots;
-
Dust and erosion control
should be provided for exposed soil;
-
For tree planting
operations, method statement should be checked against specification
requirements;
-
All retained trees within
the working boundary should be checked regularly;
-
Control over appearance of
hoarding, construction plants / machines;
-
Security floodlights should
be carefully selected to avoid light pollution.
Monitoring Schedule for the Coming Months
7.5
The tentative schedule for
environmental monitoring in August 2008 is provided in Appendix L.
8.
CONCLUSIONS
AND RECOMMENDATIONS
Conclusions
8.1
The construction phase of
the project commenced in April 2008.
8.2
1-hour TSP and 24-hour TSP monitoring
was carried out in the reporting month. All monitoring results complied with
the action / limit level. No exceedance was recorded.
8.3
All impact daytime noise
monitoring results complied with the limit level in the reporting month.
8.4
Environmental site inspections were carried out 5
times in July 2008. Recommendations on remedial actions were given to the
Contractor for the deficiencies identified during the site audit.
8.5
Three landscape and visual audits
were carried out in the reporting month. The Contractor was recommended to provide more
adequate protection to existing trees in the work areas and keep all C&D
materials / equipments / sand bags away from the
trees. The Contractor was also recommended to apply root protective sealant to
the wounded root and the Engineer’s agreement should be sought for excavation
works near existing tree roots in order to minimize damage to the tree root
system. If root pruning is required,
prior approval from Engineer is required.
8.6
Construction materials
placed near tree trunks and spillage of concrete near soil nailing areas were
observed. Some of the plants were not
properly protected during soil nailing works and serious damages to root systems
were recorded. One recently dead tree
was found within the works area.
8.7
No environmental complaint,
notification of summons and prosecution was received in the reporting month.
Recommendations
8.8
According to the environmental
site inspections performed in the reporting month, the following
recommendations were provided:
Air Quality Impact
-
Soil nail workstations on
site should be fully enclosed; and
-
Exposed earth surface at all
working platforms should be covered with tarpaulin sheets.
Construction Noise Impact
-
Nil
Water Quality Impact
-
U-channels should be kept
clear of mud, debris, construction waste and leaves;
-
Soil and earth at all working
platforms should be cleared; and
-
The desilting tank near Row
D should be maintained properly.
Chemical and Waste
Management
-
Drip trays should be
provided to all plants and chemical containers on site;
-
Oils and fuels should be
stored in designated area;
-
Sand bags and C&D
materials should be kept away from the trees;
-
C&D waste, debris and
general refuse on-site should be collected, handled and disposed of properly;
and
-
Waste skips should be
provided to collect general refuse and construction wastes.
Ecological Impact
-
Hessian sacking should be
wrapped around the trunk of vegetation to prevent damage during the
transportation of construction materials.
Landscape and Visual Impact
-
Soil nails on site should
avoid tree trunks and tree roots;
-
More adequate protection
should be provided to existing trees in the work areas and during drilling
works; and
-
Stockpiling of any
construction materials / equipments / sand bags against or near existing tree
should be avoided.
