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 from January 2009 to March 2009. As informed by the Contractor,
construction activities carried out in the reporting quarter were:
-
Soil
nailing works at Portion B2;
-
Soil nail head construction at
Portion A1, Portion A2, Portion B1 and Portion C; and
-
Rock slope stabilization works
at Portion B2, Portion C and Portion D.
Environmental Monitoring
Works
EM&A Programme
A summary of monitoring and audit activities
conducted in the reporting quarter is listed below:
|
24-hour TSP monitoring
|
15
|
sessions
|
|
1-hour TSP monitoring
|
45
|
sessions
|
|
Daytime Noise monitoring
|
12
|
sessions
|
|
Ecology monitoring
|
6
|
sessions
|
|
Landscape and Visual Audit
|
6
|
sessions
|
|
Environmental Site Inspection
|
12
|
sessions
|
|
|
|
|
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 quarter, 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 quarter.
.
Scope
of Report
1.1
This is the forth Quarterly Environmental
Monitoring and Audit (EM&A) Summary 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 January 2009 to March 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
|
Freddie Chan
|
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
|
Ken
Fong
|
3188
0538
|
3188
1710
|
|
ET
(ENSR)
|
ET
Leader
|
Edith
Ng
|
3105
8525
|
2891
0305
|
Summary of Construction Works
1.3
The Contactor has carried
out major activities in the reporting quarter. Details of the works undertaken
in this reporting period are listed below:
-
Soil
nailing works at Portion B2;
-
Soil nail head construction at
Portion A1, Portion A2, Portion B1 and Portion C; and
-
Rock slope stabilization works
at Portion B2, Portion C and Portion D.
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.
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.
Air Quality
3.1
Air quality monitoring,
including 1-hr and 24-hr TSP, was conducted at least 3 times every 7 days and
at least once every 7 days respectively at the 2 monitoring stations (CA1 and
CA2), in accordance with the EM&A Manual. Forty-five 1-hr TSP and fifteen
24-hr TSP monitoring events were carried out in this reporting quarter.
3.2
The weather was mostly sunny in
the reporting quarter. The trend of air quality for the reporting quarter 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.
3.3
There was no Action and Limit
Level exceedance recorded for both 1-hr and 24-hr TSP in the reporting quarter.
3.4
Table 3.1 presents the number
of exceedances recorded in each month of the reporting quarter. The number of
monitoring events included regular monitoring events and additional ones, if
any.
Table 3.1 Summary of Number of
Exceedances for 1-hr & 24-hr TSP Concentration
|
Monitoring Parameter
|
Location
|
Level of Exceedance
|
Month
|
|
Jan 09
|
Feb 09
|
Mar 09
|
|
1-hr TSP
|
CA1
|
No. of monitoring events
|
15
|
15
|
15
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
CA2
|
No. of monitoring events
|
15
|
15
|
15
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
|
24-hr TSP
|
CA1
|
No. of monitoring events
|
5
|
5
|
5
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
CA2
|
No. of monitoring events
|
5
|
5
|
5
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
Construction Noise
3.5
Noise monitoring was conducted at
the 2 monitoring stations (CN1 and CN2) for at least once per week during 0700
– 1900 of the reporting quarter. Twelve noise monitoring events were conducted
in the reporting quarter.
3.6
As no noise complaint was
received in the reporting quarter, no Action Level exceedance was recorded. All
measured noise levels were below the Limit Level and the graphical plots of
trends of the monitoring results are provided in Appendix F.
3.7
Table 3.2 presents the number
of exceedances recorded in each month of the reporting quarter. The number of
monitoring events included regular monitoring events and additional ones, if
any.
Table 3.2 Summary of Number of Exceedances for Daytime Noise
|
Monitoring Parameter
|
Location
|
Level of Exceedance
|
Month
|
|
Jan 09
|
Feb 09
|
Mar 09
|
|
Daytime Noise
|
CN1
|
No. of monitoring events
|
4
|
4
|
4
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
|
CN2
|
No. of monitoring events
|
4
|
4
|
4
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
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.
Ecology
3.9
Ecological monitoring was
carried out twice a month by a suitably qualified local ecologist to check on
the health and condition of the plant species of conservation interest. Six
ecological monitoring were conducted in the reporting quarter.
3.10
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. Most of the tagged vegetation has been fenced off and was found to be in
good condition during the monitoring visits in the reporting quarter.
3.11
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.
3.12
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.
3.13
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.
3.14
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.
3.15
Some recently dead trees were
recorded within the works area. The
Contractor advised that the report on dead trees found within works area will
be provided before February 2009.
3.16
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.
3.17
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.
Landscape
and Visual
3.18
Bi-weekly landscape and visual
audit was conducted by a Registered Landscape Architect (RLA) to monitor the
implementation of landscape and visual mitigation measures. Six landscape and
visual audits were conducted in the reporting quarter.
3.19
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.
3.20
It was still observed that
rectification of many of the tree identification numbers for the existing
retained trees were outstanding. The
Contractor was reminded to re-instate the tree numbers on existing trees for
ease of reference as soon as possible.
3.21
It was noted that compensatory
planting proposal for the replacement of dead tree T611 was outstanding. The Contractor was recommended to seek
Engineer’s agreement on the replacement planting as soon as possible.
3.22
It was noted that the
Contractor’s clarification of the status of existing trees T516, T517, T666,
and T698 located immediately outside of the works boundary was
outstanding. The Contractor was reminded
to provide necessary information as soon as possible.
3.23
It was still observed that
cleansing of fine dust deposited on trees was still outstanding. The Contractor was reminded to hose down the
trees on a regular basis to prevent adverse affects on tree growth in future.
3.24
It was observed that the
Contractor had stockpiled subsoil drain pipes, bags of excavated soil and small
boulder at base of existing trees. The
Contractor was requested to clear them away from the trees as soon as possible.
3.25
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.
3.26
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.
Environmental Site
Inspection
3.27
There were 12 site inspections
conducted in the reporting quarter 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
described below.
Air Quality
3.28
No adverse observation was
identified in the reporting quarter.
Noise
3.29
No adverse observation was
identified in the reporting quarter.
Water Quality
3.30
Muddy water was observed
running down the slope at BA11. The Contractor was advised to provide sand bag
bundings as primary desilting facility at the slope.
3.31
Exposed sediment was observed
accumulated on the slope of Row Y and on the platform of Row AJ. The Contractor
was reminded to clear the exposed sediment regularly.
3.32
Deposited silt was observed
accumulated inside the u-channel at Row R. The Contractor was reminded to clear
the u-channel regularly.
3.33
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.
3.34
Leaves were observed accumulated
inside the u-channel at Row C and Row R. The Contractor was reminded to clear
the u-channel regularly.
Chemical and Waste Management
3.35
A chemical container at Row AQ
and soil nail installation controllers at Row
AR and Row K were observed placed
on ground without drip tray. The Contractor was reminded to provide drip tray
to all chemical containers and plants on site.
3.36
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.
Ecology
3.37
Four individuals tagged
vegetation of conservation interest (V015, V016, V017 and V018) were lost. To
protect the tagged vegetation of conservation interest, the Contractor was
advised to fence off the tagged individual plants properly and strictly
restrict the unauthorized access of the site workers to the area.
3.38
Muddy runoff was observed
running down a slope along the bank of a dried-up hill stream near BA11. The
Contractor was advised to add sand bag bundings for desilting, and direct the
runoff towards silt trap facilities.
3.39
Four individuals tagged vegetation
of conservation interest (V015, V016, V017 and V018) were still missing.
3.40
A large number of plant species
of conservation interested were affected by construction activities. Muddy runoff and grout leakage were observed
within works areas.
3.41
The leaves of vegetation near
soil nailing areas were covered heavily with soil / dust.
3.42
Some recently dead trees were
recorded within works areas.
3.43
A tagged vegetation of
conservation interest (V059) was pressed downed by scaffolding materials. The
Contractor was advised to fenced off the vegetation properly with a clear sign
notable to all the construction workers and restrict any unauthorized access to
the area.
3.44
Electric cable wires were found
hanging on tress or being tied to small branches of vegetation/tree. The Contractor was recommended to take
necessary measures to prevent mechanical damage to all vegetation as far as
practical within the construction site.
Landscape and Visual
3.45
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.
3.46
It was still observed that
rectification of many of the tree identification numbers for the existing
retained trees were outstanding. The
Contractor was reminded to re-instate the tree numbers on existing trees for
ease of reference as soon as possible.
3.47
It was noted that compensatory
planting proposal for the replacement of dead tree T611 was outstanding. The Contractor was recommended to seek
Engineer’s agreement on the replacement planting as soon as possible.
3.48
It was noted that the
Contractor’s clarification of the status of existing trees T516, T517, T666,
and T698 located immediately outside of the works boundary was
outstanding. The Contractor was reminded
to provide necessary information as soon as possible.
3.49
It was observed that rocks from
broken-up boulders were placed against an existing tree on slope. The Contractor was requested to urgently
remove the rocks away from the tree to prevent permanent damage.
3.50
It was observed fine dust from
the soil nail drillings works had been deposited on trees. The Contractor was reminded to hose down the
trees on a regular basis to prevent adverse affects on tree growth in future.
3.51
It was observed that the
Contractor had stockpiled subsoil drain pipes and bags of excavated soil
against existing trees. The Contractor
was requested to clear the drain pipes and soil bags away from the trees as
soon as possible.
3.52
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.
3.53
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.
3.54
It was observed that wood
formworks and construction materials were piled at the base of existing tree
T638. The Contractor was requested to
clear the construction materials away from the tree as soon as possible.
3.55
It was observed that discarded
lump of concrete fill material was placed against existing tree trunk. The Contractor was requested to clear the
construction waste away from the tree as soon as possible.
3.56
It was observed that the
Contractor had hung electrical cords on the dead and leaning trees near
existing tree T534 which was previously recommended to remove. The Contractor was requested to remove the
electrical cords to prevent accidental pulling of the leaning tree.
4.
Advice on Solid and liquid
Waste Mangement Status
4.1
The Contractor has 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 quarter.
4.2
As advised by the Contractor, 34.08 ton of inert
C&D waste was disposed offsite to Chai Wan and 15.92 ton of non-inert
C&D waste was disposed offsite to SENT landfill in the reporting period.
C&D waste generated was reused on site as much as possible.
Summary
of Exceedances and Review of the Reasons for non-compliance
5.1
There was no 1-hr TSP, 24-hr
TSP and noise exceedance recorded in the reporting quarter.
6.1
No environmental complaints,
notification of summons and prosecution was received in the reporting quarter.
Table 6.1 summarized the complaint, summons and successful prosecution received
in the reporting period.
Table 6.1 Summary of Environmental
Complaints and Prosecutions
|
|
January 2009
|
February 2009
|
March 2009
|
Total
|
|
Complaint Logged
|
0
|
0
|
0
|
0
|
|
Summons
Served
|
0
|
0
|
0
|
0
|
|
Successful Prosecution
|
0
|
0
|
0
|
0
|
|
Total
|
0
|
0
|
0
|
0
|
7.
Comments, Recommendations
and Conclusions
Comments
on Mitigation Measures
7.1
According to the environmental
site inspections performed in the reporting quarter, the following recommendations
are provided:
Air Quality
-
Soil nail workstations on
site should be properly enclosed.
Noise
-
N/A
Water Quality
-
Sedimentation tanks on site
should be properly maintained;
-
Site effluent must be
collected and treated prior to discharge to public drain;
-
U-channels should be kept
clear of mud, debris, leaves, construction waste and materials; and
-
Soil and exposed earth at
all working platforms and slopes should be cleaned up.
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;
-
Empty chemical containers
should be disposed of as chemical waste;
-
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.
Ecology
-
Regular watering should be
carried out to wash dust covered on leaves of vegetation;
-
All plant species of
conservation interest should be fenced off properly with clear sign, especially
for those located near major access road and areas likely to be impacted by
construction activities;
-
Site runoff should be directed towards regularly
cleaned and maintained silt trap facilities to prevent sedimentation impact.
-
The Contractor was reminded
to take all necessary actions to prevent grout leakage and muddy run-off to the
surrounding natural environment;
-
All recently dead trees
found within works areas should be reported to relevant government department(s)
for record purpose;
-
The Contractor was reminded
to take all necessary actions to preserve the identified vegetation of
conservation interest;
-
All site access should be
clearly demarcated and no excessive removal of vegetation in natural areas
adjacent to the site access should be allowed; and
-
The Contractor was recommended to take necessary
measures to prevent damage to all vegetation within the construction site.
Landscape and Visual
-
Dead / rotten trees, especially
T511 which was now found infected by termite, should be removed from site for
safety. The Contractor was also reminded to record and report all dead trees as
found on site to the Engineer for record;
-
All ineligible tree
identification numbers should be rectified for all existing trees;
-
The status of missing trees
should be clarified as soon as possible;
-
Engineer’s agreement on the
replacement planting for dead tree should be sought;
-
Fine dust deposited on
trees due to soil nailing works should be hosed down from trees as soon as
possible;
-
Construction materials,
soil bags, excavated rocks, boulders and pipe stockpile should be kept clear
from existing tree and should not be placed against trees in future; and
-
The Contractor was
recommended to minimize the excavation of soil nail head areas for concreting
as far as practicable in order to minimize damage to existing tree roots.
Recommendations
on EM&A Programme
7.2
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. Assessment and analysis
of monitoring results collected demonstrated the environmental acceptability of
the Project. 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.
7.3
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.
Conclusions
7.4
Air quality and noise
monitoring, ecological monitoring, bi-weekly landscape and visual audit and
weekly site inspection were carried out from January 2009 to March 2009, in
accordance with the EM&A Manual.
7.5
No Action and Limit Level
exceedance or non-compliance was recorded for the monitoring works in the
reporting quarter.
7.6
No environmental complaint,
summons or prosecution was made against the Project in the reporting quarter.
