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., which
was integrated into AECOM Asia Company Limited as of 1 May 2009, 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.
The
termination of the construction phase EM&A programme
of the Project was approved by EPD on 31 December 2009.
This
Final EM&A Review Report summarizes the findings
of EM&A works conducted in the construction period from April 2008 to December 2009. The construction activities carried
out in the reporting period were:
- Test nails for pull out test;
- Permanent nails installation;
- Site clearance for soil nail setting;
- Setting out of locations of soil nail;
- Soil Nail Installation;
- Erection of scaffolded and working platform;
- Soil nail head preparatory works;
- Soil nail construction;
- Soil nail head construction;
- Rock slope stabilization works;
- Slope reinstatement works;
-
Removal of winch system;
-
Laying of corrosion mat and wire mesh to soil profile at soil nailing
area;
-
Hydroseeding; and
-
Compensatory planting to soiling nailing area.
Environmental Monitoring
Works
EM&A Programme
A summary of monitoring and audit activities conducted
in the reporting period is listed below:
|
24-hour TSP monitoring
|
108(CA1)/110(CA2)
|
sessions
|
|
1-hour TSP monitoring
|
111
|
sessions
|
|
Daytime Noise monitoring
|
92
|
sessions
|
|
Ecology monitoring
|
42
|
sessions
|
|
Landscape and Visual Audit
|
46
|
sessions
|
|
Environmental Site Inspection
|
91
|
sessions
|
|
|
|
|
Breaches of Action and Limit Levels
There
was no Action / Limit level exceedance recorded for
1-hour and 24-hour TSP monitoring throughout the construction period of the
Project.
All
noise level recorded complied with the Limit level throughout the construction
period of the Project. No noise related complaint was received in the reporting
period, hence no Action Level exceedance
was recorded.
Complaint, Notification of Summons
and Successful Prosecution
There
were two (2) environmental complaints received in the reporting period.
EPD referred two complaints from residents nearby
Po Shan Mansions, regarding construction dust emission
from the slope work at Po
Shan Road in May 2009. Through on-site investigation, construction dust could
potentially be generated from soil nail drilling works of the Project. Although
all the 1-hr and 24-hr TSP monitoring results in May 2009 did not exceed the
Action levels, the Contractor was recommended to improve mitigation measures to
prevent dust emission as far as possible. EPD had inspected the site on 22 May
2009
and had no adverse comment
on the dust control measures carried out on site. During follow-up site
inspections
by ET, enhanced
mitigation measures were taken by the Contractor and no significant
construction or fugitive
dust was observed.
There was no
notification of summons and successful prosecution received in the reporting period.
Scope
of Report
1.1
This is the Final EM&A
Review 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, and list of activities carried out by the ET for
the Project for the period from April 2008 to December 2009.
Project Organization and Contacts of Key
Management
1.2
The project organization is shown in Appendix A.
The key personnel contact names and numbers are summarised 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
|
Lawrence Shek
|
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
|
C. Y. Mak
|
3188 0538
|
3188 1710
|
|
Safety and
Environmental Officer
|
Yue Kin Fung
|
3188 0538
|
3188 1710
|
|
ET (AECOM)
|
ET Leader
|
Edith Ng
|
3105 8525
|
2891 0305
|
Summary of Construction Works
1.3
Construction works undertaken by the Contractor
during the construction period of the Project are listed below:
- Test nails for pull out test;
- Permanent nails installation;
- Site clearance for soil nail setting;
- Setting out of locations of soil nail;
- Soil Nail Installation;
- Erection of scaffolded and working platform;
- Soil nail head preparatory works;
- Soil nail construction;
- Soil nail head construction;
- Rock slope stabilization works;
- Slope reinstatement works;
-
Removal of winch system;
-
Laying of corrosion mat and wire mesh to soil profile at soil nailing
area;
-
Hydroseeding; and
-
Compensatory planting to soiling nailing area.
1.4
The general layout plan of the Project site
showing the contract area is shown in Figure 1.1.
1.5
The construction programme
is provided in Appendix B.
1.6
The mitigation measures implementation schedule
are presented in Appendix C.
2. Environmental Monitoring And Audit Requirements
Monitoring Parameters
2.1
The
EM&A Manual designated two monitoring stations to monitor environmental
impacts on air quality and noise due to the Project. The monitoring locations are
depicted in Figure 2.1.
2.2
The
EM&A Manual also required ecology monitoring, bi-weekly landscape and
visual audits, and environmental site inspections for air quality, noise, water
quality, chemical, waste management, ecology and landscape and visual.
Environmental Quality Performance Limits (Action/Limit
Levels)
2.3
The
environmental quality performance limits (i.e. Action/Limit levels) were
derived from the baseline air quality monitoring results of Access road to Po Shan Mansions
(CA1) and Podium of Hamilton Court (CA2) and / or as defined in the EM&A Manual
(CN1 & CN2), and are given in
Appendix D.
Environmental Mitigation Measures
2.4
Relevant environmental mitigation measures were stipulated in the Particular
Specification and EP (No.: EP-235/2005/B) for the Contractor to adopt. A list
of mitigation measures and their implementation statuses are given in Appendix C.
Monitoring Requirements
3.1
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
3.2
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
3.3
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
3.4
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
3.5
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.
1-hour TSP Monitoring
Measuring Procedures
3.6
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
3.7
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 monitoring.
Monitoring Result
3.8
One hundred and eleven (111) 1-hr
TSP monitoring events were carried out in the reporting period. For 24-hour TSP
monitoring, one hundred and eight (108) monitoring events were conducted for CA1,
while one hundred and ten (110) monitoring events were carried out for CA2 in
the reporting period.
3.9
The weather during the
monitoring sessions was mostly fine and sunny. The trend of air quality for the
reporting period are given in Appendix E. Major dust source of the construction
works area included soil nail installation activities from the Project, construction
activities of another project under the same contract (concurrent project)
carried out in the vicinity and nearby traffic emissions.
3.10
There was no Action and Limit level
exceedance recorded for both 1-hr and 24-hr TSP during
the course of the construction period of the Project.
Monitoring Requirements
4.1
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
4.2
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 NC73
|
Monitoring Locations
4.3
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
4.4
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.
Monitoring Results
4.5
Ninety-two (92) noise monitoring
events were conducted in the reporting period.
4.6
No noise related complaint was
received in the reporting period, hence no Action Level
exceedance was recorded.
4.7
All measured noise levels were
below the Limit level and the graphical plots of trends of the monitoring
results are provided in Appendix F.
4.8
Major noise sources during the
noise monitoring included the construction activities from the Project, from
another project under the same contract (concurrent project) carried out in the
vicinity and nearby traffic noise.
Monitoring
Requirement
5.1
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.
5.2
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
5.3
The ecological monitoring was
carried out for plant individuals of conservation interest identified within
the proposed works area.
Monitoring
Methodology
5.4
The ecological monitoring was
conducted twice monthly by a suitably qualified local ecologist to check on the
health and condition of the plant species of conservation interest. Forty-two
(42) ecological monitoring was conducted in the reporting period.
5.5
The plants of conservation
interest, which were tagged during the baseline survey, were checked during
each monitoring.
Monitoring Results
5.6
A total of 13 plant species of
conservation interest (i.e. V001 to V013) were identified within the area
during an earlier Detailed Vegetation Survey conducted under this Project. V001 to V013 were found to be in good
condition during the monitoring visits in the reporting period, nevertheless,
plastic fencings supported by strong poles were recommended to demarcate plant
locations clearly to prevent tipping and entry of personnel in order to avoid
damage to the plants. Fencings had been set up in the area during the
monitoring visits in May 2008.
5.7
The bark of two individuals of
vegetation located adjacent to the temporary conveyor belt was found to be
slightly damaged. It was recommended that hessian sacking should be wrapped
around the trunk of vegetation to prevent damage during the transportation of
construction materials. The concerned
trunks were found to be wrapped during the second visit in May 2008.
5.8
Construction materials such as
planks, sand bags and metal rods were found to be placed over or near the lower
trunks of some trees. It was recommended
that these materials should be kept in proper place to avoid damage to
vegetation within works area.
5.9
Concrete was found 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.
5.10
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.
5.11
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.
5.12
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.
5.13
The trunk of a tree (tree tag
number T344) located next to a soil nailing area in Row O was covered with
concrete.
5.14
The lower
trunk of Tree No. T5955 adjacent to soil nailing
position on Row AF was covered with grout.
5.15
One of the main branches of a
plant (Glochidion wrightii)
on Soil Nailing Row X was cut to give way to machinery. The Contractor was advised that trimming of
plant within works area is not allowed.
5.16
A proper handrail for site
access to the south of Row AF should be set up instead of tying ropes on trees
as support.
5.17
Tree No. T611 (Schefflera heptaphylla) on Row R
was found to be in very poor condition. A
recently dead tree on Row AF was tipped to one side.
5.18
Vegetation located between Row
AO to AU was excessively removed during site clearance. The plant debris was dumped in the adjacent woodland habitat outside the works area.
5.19
The unpaved area adjacent to
the footpath at Row R was utilized as a main site access, soil on this area was
found to be heavily eroded to expose the root system of nearby vegetation. The unpaved area was subsequently covered
with sand bags.
5.20
A large number of metal rods
were placed outside the soil nailing area.
Some of them were merely supported by shrubs.
5.21
The leaves of vegetation
located near the operation of soil nailing were covered with dust.
5.22
A heavy cable of the soil
nailing machine was found hanging on tree trunk and branch T6788 and T9795.
5.23
Trunks of trees located above Row AR
were not covered with warping for protection while site clearance and
scaffolding works were underway.
5.24
Signs of grout leakage on a
natural drainage path were recorded. The
hardened grout covered the drainage path between Row AB to
Row AQ, and a large amount of the tagged vegetation of conservation interest (Cibotium barometz) was
affected. As most of the tags of the
affected individuals were disappeared and leaves were also seriously damaged,
it was therefore not able to identify the exact number of affected individuals
on site. However, judging from the
extent of the grout leakage, it is believed that vegetation tagged as V022,
V023, V024, V025, V026, V027, V028, V029, V030, V031, V032, V033, V034, V035,
V036, V037 and V038 were affected. At
the time of monitoring visit, the Contractor was recommended to remove all
hardened grout from the vegetation as well as the soil surface
immediately. To prevent further damage
to the tagged vegetation, the Contractor was advised to fenced off the
vegetation properly and restrict any unauthorized access of site workers to the
area.
5.25
The leaves of vegetation
located near the operation area of soil nailing works were covered heavily with
dust and were subsequently washed by soil nail contractor upon request. Some of the fabric shields next to the soil
nailing machine were found to be worn out.
5.26
A major site access near Row AF
was not clearly demarcated and vegetation was removed to give way to the
access.
5.27
Most of the harden grout from
the previous leakage incident in December 2008 covering on the vegetation and
soil surface had been removed by the Contractor. Four individuals vegetation of
conservation interest tagged as V015, V016, V017 and V018 were missing. It was
believed that they were covered by the leaked grout and removed during the
cleaning process. To prevent further damage to the tagged vegetation, the
Contractor was advised to fenced off the vegetation properly and restrict any
unauthorized access of site workers to the area.
5.28
The leaves of vegetation
located near the operation area of soil nailing works were covered heavily with
dust and were subsequently washed by the Contractor upon request.
5.29
A large area of leaked grout
and muddy run-off was found in most soil nailing works areas. The plant species of conservation interest
(such as V022 to V035) located within these areas were
almost wiped out and cannot be located on site during the monitoring visits.
5.30
The leaves of vegetation
located near the operation area of soil nailing works were covered heavily with
dust and were subsequently washed by the Contractor upon request.
5.31
Fencing of a vegetation of
conservation interest (V059) was worn out. A lower branch of the tagged vegetation was
carelessly pressed down by scaffolding materials near an assess
road. Damage of the tagged vegetation
was sighted. The Contractor was advised
to fenced off the vegetation properly with a clear signage notable to all the
construction workers and restrict any unauthorized access to the area.
5.32
Electric cable wires were found
hanging on tress or being tied to small branches of vegetation/tree within the
construction site. The Contractor was
recommended to hang the cable wires on or along the engineering scaffold instead
of on the body part vegetation/tree to prevent mechanical damage to the
vegetation/tree.
5.33
Three individuals of vegetation
of conservation interest in Group V015, V016 and V017 had been identified and tags
tied back during the 28 April 2009 visit.
The Contractor agreed to fence off two of the individuals which were
located outside the existing fence-off area.
The Contractor was also advise to erect a clear
sign notable to all the construction workers and restrict any unauthorized entry
to the area.
5.34
Another two vegetation of
conservation V018 and V035 could not be located during the monitoring visits, The
Contractor advised the concerned vegetation were probably covered up under the
temporary storage platform and scaffolding, the Contractor agreed to identify
the missing individual once the platform has been removed from the site.
5.35
Hardened grout was found in the
natural habitat near the Project area.
To prevent the plant from being affected by grout leakage and muddy site
run-off, the Contractor was reminded to remove any grout from the natural
habitat as soon as possible and add sand bags around the hardened grout.
5.36
Sign of oil / lubricant
spillage was observed from soil nailing machine on the nearby vegetation. The Contractor was recommended to remove any
soil nailing machine from the vegetation.
5.37
Part of the plant species of
conservation interest were not properly fenced off or tagged, particularly in
works area above Row AD. The Contractor
was advised to fence off and label the vegetation properly with a clear sign
notable to all the construction workers and restrict any unauthorized access to
the area.
5.38
During monitoring visit on 2 June 2009, a number of vegetation of
conservation interest were missing from site, including V057, V058, V063, V056,
V054, V055, V052, and V042. And some
others were not fenced off, including V065, V051, V053, V048, V049, V050, V043,
V044, V045, V046, and V047. The missing
vegetation were subsequently found and tagged in 23 June 2009 visit apart from
V054. The eleven unprotected were also
fenced off.
5.39
A vegetation of conservation
V018 was found to be in very poor condition.
5.40
Soil of natural terrain along
an access road (near Row AH) was not well covered.
5.41
During monitoring visit on 7
July 2009, the previously missing vegetation of conservation interest V054 were located and tagged. However, another two individuals V086 and V088 were not properly fenced off.
5.42
A vegetation of conservation
V018 located during the May 2009 monitoring visit was still in very poor
condition.
5.43
Soil of natural terrain along
an access road (near Row AH) was not well covered.
5.44
General refuse was accumulated
within demarcated area with vegetation of conservation interest. The Contractor
was reminded to remove the general refuse.
5.45
Sandbags and stones were
observed piled against a few trees. The Contractor was requested to keep the
sandbags and stones away from the trees.
5.46
During the inspections in
December 2009, it was observed that shrubs had been planted within the within
the impacted areas under this Project to compensate for the loss of understorey vegetation of the woodland habitat due to the
construction of landslide preventive works.
6.
Landscape and Visual Audit Results
Monitoring
Requirement
6.1
During the construction phase
of the Project, landscape and visual monitoring was 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.
6.2
Bi-weekly landscape and visual
audit was conducted by a Registered Landscape Architect (RLA) to monitor the
implementation of landscape and visual mitigation measures. Forty-six (46)
landscape and visual audits were conducted in the reporting period.
Monitoring Results
6.3
The bark of existing tree T254
was damaged by the works as no tree protection was provided. The Contractor was requested to carry out
tree protection works for the tree as soon as possible.
6.4
The tree bark of one existing
was damaged by the erection of the temporary conveyor / pulley system on the
slope just immediately outside of the site boundary of Landslide Preventive
Works. The Engineer was requested to
clarify if it is considered part of the soil nail works.
6.5
An existing dead tree was
partially uprooted and fallen over. The
Contractor was requested to clear the dead tree for safety consideration.
6.6
One of the temporary shelter
areas was installed against some branches of an existing tree. The Contractor was requested to re-adjust the
temporary shelter to clear of the tree branches so as not to cause damage to the
tree.
6.7
The wrapping of hessian for the
tree protection of some of the trees had been wrapped with two tree trunks
together. The Contractor was reminded to
individually wrap the trees and not to force the tree trunks together.
6.8
Overhead plastic sheets for
rain shelter were tied to existing tree branches. The Contractor was reminded that the trees
should not be used for temporary anchoring of works and to untie from tree
branches as soon as possible.
6.9
The construction of some of the
soil nail drilling platforms surrounds existing trees, which was protected with
only hessian clothes. The Contractor was
requested to provide more protection to these trees by the use of wooden slats
strapping around the trunks to prevent accidental damage to tree barks by heavy
equipment / tools during the drilling works.
6.10
Minor damage to the tree bark
at the base of one tree on slope was observed.
The Contractor was reminded to be more carefully when carry out works
near existing trees.
6.11
Construction equipments, metal
pipes / steel bars were observed stockpiled against the tree trunks of existing
trees at several locations on site. The
Contractor was requested to clear the equipment and construction materials and
not to place them against trees in future in order to prevent damage to the
trees.
6.12
Soil bags, construction waste
and materials were observed placed on slopes and rested at the base of the tree
trunks. The Contractor was requested to
clear the soil bags away from the base of the tree as soon as possible.
6.13
Sealing of the root wounds for
tree T247 was still outstanding. The
Contractor was reminded to apply protective sealant to prevent the roots from
rotting as soon as possible.
6.14
A number of minor tree branches
were observed damaged by typhoon. The Contractor was requested to prune the
broken tree branches back to living tissues as soon as possible.
6.15
A couple of dead trees,
including a tree with rotten trunk at the base were observed near existing tree
T534. The Contractor was recommended to remove all the dead and dying trees
away from the footpath area for the safety of workers.
6.16
Many of the trees numbers were
obscured by recently wrapped hessian tree protection. The Contractor was requested to re-instate
the tree numbers on existing trees for ease of identification.
6.17
The leaves of existing tree
T611 were wilted due to dry soil condition.
The Contractor was recommended to water the tree on a daily basis and to
monitor the condition of the tree.
6.18
It was still observed that the
Contractor had not removed the dead trees, including a tree with rotten trunk
at the base located near existing tree T534.
The Contractor was recommended to remove all the dead and rotten trees
away from the footpath area for safety.
6.19
The leaves of previously wilted
tree T611 had dried out and was dead eventually. The Contractor was recommended
to seek Engineer’s agreement on the replacement planting.
6.20
It was observed that the
Contractor had tied the toe board onto the existing tree trunk. The Contractor was requested to remove it as
soon as possible.
6.21
Rectification of many of the
tree identification numbers for the existing retained trees was
outstanding. The Contractor was reminded
to re-instate the tree numbers on existing trees for ease of reference as soon
as possible.
6.22
Existing trees T516, T517, T666, and T698 immediate outside of
works area boundary were missing and clarification of the status of existing
trees T516, T517, T666, and T698 was outstanding. The Contractor was requested to clarify the
status of the missing trees for information and record.
6.23
Several undersized existing trees were broken. The Contractor was reminded to be more
careful in order to minimize damage on trees in future.
6.24
The Contractor had pruned some of the existing tree
branches to facilitate soil nailing works.
However, as required under the contract Particular Specification, the
Contractor shall seek the Engineer’s agreement prior to carry out any tree
pruning works. Therefore, the Contractor
was reminded to seek Engineer’s agreement for pruning of existing trees in
future.
6.25
Some excavated rocks for soil nail heads were piled
against the based of an existing tree. The Contractor
was reminded to clear the rocks away from the tree as soon as possible.
6.26
A tree was observed with its branch hacked off and
left with scars. The Contractor was
reminded that pruning of tree branch requires permission from the Engineer and
that pruning of tree branch shall be carried out by approved landscape
contractor.
6.27
The Contractor had used an existing tree as support to
tie the large hose. The Contractor was
requested to remove the hose from the tree as soon as possible.
6.28
The tree bark of an existing tree with protective
hessian wrappings was damaged by scrapings from the moving of pipe sleeves for
stock piling nearby. The Contractor was requested to provide better tree
protection and to ensure moving of equipments and materials do not damage
existing trees.
6.29
It was observed that some
excavation for soil nail heads concreting area was larger than necessary,
causing unnecessary damage to the existing tree roots. The Contractor was reminded that the
excavation of soil nail areas should be kept to the minimum to minimize damage
to the existing trees.
6.30
It was found that a termite tube
had infected the dead tree T511 at the corner of footpath stair. The Contractor was request to urgently remove
the infected dead tree for consideration of safety of the workers and the
public in future.
6.31
It was observed that electrical
cables were strung overhead and hanged from tree branches. The Contractor was requested to remove the
electrical cables away from the trees as soon as possible.
6.32
It was observed that the
Contractor had tied safety ropes around the base of several existing trees for
the works. The Contractor was reminded
that the practice was not acceptable and was requested to remove the ropes as
soon as possible.
6.33
It was observed that soil was
compacted against the base of a small existing tree on the upper slope side and
used as passage area. The Contractor was
reminded the practice was unacceptable and the compacted soil is to be removed
and constructed with proper passage without affecting the existing tree if
required.
6.34
It was observed that the
Contractor had tied ropes to the base of existing tree T668 for support of the
large air hose. The Contractor was
requested to remove the rope from the base of the tree.
6.35
It was observed that an
existing tree on the slope which had partially grown above an existing boulder was undermined by the recent removal of the boulder due to
engineering safety considerations. The
tree root system was partially undermined and exposed, which would lead to
dry-out and possible collapse during strong winds and typhoons. The Contractor was recommended to back-filled
the pit and compact the slope surface area to stabilize the tree.
6.36
It was observed that the
make-shift materials conveyor system had its edge board encircled an existing
tree, with the tree trunk being easily damaged by the conveyor ‘boat’. The Contractor was requested to rectify the
edge board to ensure that conveying of materials would not damage the tree
trunk.
6.37
It was found that a couple of
rubber air hoses had been rubbed against a tree trunk leaving black marks. The Contractor was requested to relocate the
hoses away from the tree.
6.38
It was observed a side branch
of tree T608 overhanging the footpath was structurally cracked. The Contractor was requested to prune and
remove the damaged tree branch for safety and healthy growth of the tree.
6.39
It was noted several trees were
broken by recent strong winds and Typhoon Molave. The Contractor was reminded to report
damaged trees to the Engineer for record
6.40
Nearing completion of the
construction of the Project, for safety consideration when to area is to be
re-open for the general public use, it is recommend that the side branch of
existing tree T678 overhanging the footpath with its low headroom be pruned
back to prevent any possible accidents in future. Also, the dead tree T612 with half broken
branch along the footpath is also recommended to be removed.
7.1
Ninety-one (91) site
inspections were conducted in the reporting period to monitor the
implementation of proper environmental pollution control and mitigation
measures for the Project. The major concerns for the Project are air quality,
noise, water quality, waste management, ecology and landscape and visual. Observations
recorded are summarized below. All
the observations were rectified by the Contractor within the agreed time frame.
Air
Quality
7.2
The soil nail workstation at Row
O was not fully enclosed. Although immediate action had been taken to provide
tarpaulin sheet for covering the soil nail extraction outlet, the Contractor
was still reminded to fully enclose the workstation.
Noise
7.3
No adverse observation was
identified during the course of the construction period of the Project.
Water
Quality
7.4
Construction waste, deposited
silt, debris, leaves were accumulated inside the u-channels. The Contractor was
reminded to remove the waste, silt, debris and leaves regularly and properly
maintain the drainage system.
7.5
Exposed earth surface was
observed on the slope above Row H. The Contractor was reminded to cover the
slope and provide bunding along the edge of the
u-channel under the slope to prevent muddy runoff prior to clearing the mud.
7.6
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. The Contractor was also
reminded not to spray water directly on exposed earth and make sure the
effluent would be treated before discharged to public drain.
7.7
Exposed earth was observed
around the area of soil nail installation and on the slope of the site area.
The Contractor was advised to clean up the earth as soon as the soil nail operation
was completed.
7.8
Some sand bags were found
damaged. The Contractor was advised to replace the sand bags.
7.9
Exposed slope was observed
below Row R. The Contractor was advised to compact the loose sediment on the
slope and/or to cover the slope with tarpaulin sheets.
7.10
Loose sediment was observed
accumulated on the slope above Row AI, and on the platform at Row X, Row AF and
Row AH. The Contractor was reminded to clear the sediment regularly and as soon
as the soil nailing operation finishes.
7.11
Sediment was observed
accumulated in the sand trap at Row C. The Contractor was advised to clear the
sediment more frequently especially during rainy seasons.
7.12
Stagnant water was observed
accumulated in a soil nail head at Row AA. The Contractor was reminded to clear
the stagnant water.
Chemical
and Waste Management
7.13
Oil stain was found on ground under
drill rig. The Contractor was reminded to clear the oil stain, provide a drip
tray, and properly maintain the plants on site to prevent leakage
7.14
Chemical containers and oil
containers were placed on ground without drip tray. The Contractor was reminded
to provide drip tray to all chemicals on site.
7.15
Stockpile of C&D waste and
C&D materials were found at working platforms and scattered on the slope.
The Contractor was reminded to clear the C&D waste off-site regularly and
to collect and recycle the useful materials.
7.16
Soil nail installation controllers were found
without drip trays. The Contractor was reminded to provide drip trays to the
plants on site.
7.17
Small amount of cement slurry
was found run off into the u-channel at Row R. The Contractor was reminded to
clean up the slurry inside the u-channel and prevent further runoff.
7.18
Some cement slurry was observed
on the platform of Pullout 16 and observed dripping to the slope below. The
Contractor was requested to properly clean up the slurry.
7.19
Stagnant water was observed
inside uncovered chemical containers. The Contractor was advised to pour off
the stagnant water and dispose of as chemical waste, and properly cover all
chemical containers on site.
7.20
Cement powder was observed
scattered on working platform. While immediate action by Contractor to clear
the cement powder into sand bags, the Contractor was still reminded to properly
handle all chemicals on site.
7.21
A hole was found on a drip tray
and oily water was running out. The Contractor was requested to fix the drip
tray as soon as possible.
7.22
A drip tray of a soil nailing
controller was observed accumulated with oily water. The Contractor was
reminded to remove the oily water frequently and treat it as chemical waste.
Ecology
7.23
Refer to Section 5.
Landscape and Visual
7.24
Refer to Section 6.
8.1
The Contractor was 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 period.
8.2
As advised by the Contractor, 40.5 ton and 400.82 ton
of inert C&D waste were disposed offsite to Public Filling Barging Point at
Quarry Bay and Chai Wan respectively, while 197.98
ton of non-inert C&D waste was disposed offsite to SENT landfill in the
reporting period. Also 20kg of chemical waste was collected by licenced waste collector. C&D waste generated was
reused on site as much as possible.
9. Summary of Non-Compliance
(Exceedances) of Environmental Quality
9.1
There was no 1-hr TSP, 24-hr
TSP and noise monitoring exceedance recorded during
the course of the construction period of the Project.
9.2
No noise related complaint was
received in the reporting period, hence no Action
Level exceedance of noise was recorded.
10.1
EPD referred two (2)
complaints, one on 15 May 2009 and one on 19 May 2009, from residents nearby Po
Shan Mansions, regarding construction dust emission from the slope work at Po
Shan Road. Through on-site investigation on 19 May 2008, construction dust
could potentially be generated from soil nail drilling works of the Project.
Although all the 1-hr and 24-hr TSP monitoring results in May 2009 did not
exceed the Action levels, the Contractor was recommended to improve mitigation
measures to prevent dust emission as far as possible, such as enhancement of
tarpaulin enclosures and watering facilities, during soil nail drilling works.
EPD had inspected the site on 22 May 2009 and had no adverse comment on the
dust control measures carried out on site. During follow-up site inspections by
ET on 26 May 2009, enhanced mitigation measures were taken by the Contractor
and no significant construction or fugitive dust was observed.
10.2
No notification of summons and
prosecution was received during the course of the construction period of the
Project.
10.3
A summary record of the
complaints, notification of summons and successful prosecutions is annexed in
Appendix G
11.1
The environmental monitoring data
collected during the construction period were generally well below the Action and
Limit levels, so the monitoring results were within acceptable levels which is consistent
with the EIA prediction.
12.1
The environmental monitoring
results indicated that the construction activities were in compliance with the
relevant environmental requirements and were environmentally acceptable. The
effectiveness and efficiency of the monitoring methodology and mitigation
measures were considered high as evidenced by a small number of complaints and no
monitoring exceedances.
13.1
The impact air quality and
noise monitoring programme ensured that any environmental impact to the
receivers would be readily detected and timely actions could be taken to
rectify any non-compliance. The
ecological monitoring, bi-weekly landscape and visual audit and weekly site
inspection ensured that all the environmental mitigation measures recommended
in the EIA report were effectively implemented.
13.2
The EM&A programme
effectively monitored the environmental impacts from the construction
activities and no particular recommendation was advised for the improvement of
the programme.
14.1
The construction of the Project
and the EM&A programme commenced on 1 April 2008. The termination of the
construction phase EM&A programme of the Project was approved by EPD on 31
December 2009.
14.2
Air quality and noise monitoring,
ecological monitoring, bi-weekly landscape and visual audit and weekly site
inspection were carried out from April 2008 to December 2009, in accordance
with the EM&A Manual.
14.3
No Action and Limit level exceedance or non-compliance was recorded for the
monitoring works during the course of the construction period of the Project.
14.4
Two (2) environmental complaints,
but no summons or prosecution were made against the Project during the course
of the construction stage.
14.5
Weekly site inspections and
monthly site audits were carried out by ET and Independent Environmental
Checker (IEC), respectively, to ensure proper implementation of environmental mitigation
measures specified in the EM&A Manual and compliance with environmental legislation.
The ecological monitoring and bi-weekly landscape and visual audit ensured that
all the environmental mitigation measures recommended in the EIA report were
effectively implemented.
14.6
Mitigation measures were
implemented by the Contractor to minimize the environmental impacts due to
construction activities. Site inspections carried out by ET showed that the Contractor
rectified the problems observed and no major environmental deficiency was induced.
The environmental performance of the Contractor during the construction period
was considered satisfactory.
14.7
The monitoring results and
statistics of non-compliance indicated that the EIA process with its recommended
mitigation and EM&A programme were effective for minimizing the environmental
impacts posed by the Project.
14.8
While the environmental impact
of the construction work was minimal as shown through the monitoring and audit
programme, the environmental conditions of the Project area had returned to
ambient conditions as compared to the baseline conditions, upon the completion
of construction of the Project.
