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 from October 2008 to December 2008. As informed by the Contractor,
construction activities carried out in the reporting quarter were:
-
Soil nail head preparatory
works at Portion A1;
-
Soil nail construction at
Portion A2, Portion B1 and Portion C;
-
Soil nail installation at
Portion B1 and Portion C;
-
Soil nail head construction at
Portion A1; and
-
Rock slope stabilization works
at Portion C and Portion B2.
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
|
16
|
sessions
|
|
1-hour TSP monitoring
|
48
|
sessions
|
|
Daytime Noise monitoring
|
14
|
sessions
|
|
Ecology monitoring
|
6
|
sessions
|
|
Landscape and Visual Audit
|
7
|
sessions
|
|
Environmental Site Inspection
|
13
|
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 third 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 October 2008 to December 2008.
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 nail head preparatory
works at Portion A1;
-
Soil nail construction at
Portion A2, Portion B1 and Portion C;
-
Soil nail installation at
Portion B1 and Portion C;
-
Soil nail head construction at
Portion A1; and
-
Rock slope stabilization works
at Portion C and Portion B2.
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-eight 1-hr TSP and sixteen
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
|
|
Oct 08
|
Nov 08
|
Dec 08
|
|
1-hr TSP
|
CA1
|
No. of monitoring events
|
15
|
15
|
18
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
CA2
|
No. of monitoring events
|
15
|
15
|
18
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
|
24-hr TSP
|
CA1
|
No. of monitoring events
|
6
|
5
|
5
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
CA2
|
No. of monitoring events
|
6
|
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. Fourteen 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
|
|
Oct 08
|
Nov 08
|
Dec 08
|
|
Daytime Noise
|
CN1
|
No. of monitoring events
|
5
|
4
|
5
|
|
Action
|
0
|
0
|
0
|
|
Limit
|
0
|
0
|
0
|
|
|
Total
|
0
|
0
|
0
|
|
CN2
|
No. of monitoring events
|
5
|
4
|
5
|
|
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
The lower trunk of Tree No.
T5955 adjacent to soil nailing position on Row AF was covered with grout. The grout had only been partly removed from
the lower trunk.
3.12
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.
3.13
The leaves of vegetation
located near Row AA were covered with dust.
3.14
A large number of metal rods
were placed outside the soil nailing area.
Some of them were merely supported by shrubs.
3.15
The leaves of vegetation
located near the operation of soil nailing were covered heavily with dust.
3.16
A heavy cable of the soil
nailing machine was found hanging on tree trunk and branch T6788 and T9795.
3.17
Trunks of trees located above Row AR
were not covered with warping for protection while site clearance and
scaffolding works were underway.
3.18
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.
3.19
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.
3.20
A major site access near Row AF
was not clearly demarcated and vegetation was removed to give way to the
access.
Landscape
and Visual
3.21
Bi-weekly landscape and visual
audit was conducted by a Registered Landscape Architect (RLA) to monitor the
implementation of landscape and visual mitigation measures. Seven landscape and
visual audits were conducted in the reporting quarter.
3.22
It was observed that existing
tree T611 was dead. The Contractor was
recommended to seek Engineer’s agreement on the replacement planting.
3.23
The Contractor had not removed
a couple of 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.
3.24
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.
3.25
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.
3.26
Construction waste was found piled deep around
existing tree T614. The Contractor was
requested to remove the construction waste around the tree as soon as possible.
3.27
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.
3.28
Several undersized existing trees were
broken. The Contractor was reminded to
be more careful in order to minimize damage on trees in future.
3.29
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.
3.30
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.
3.31
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.
3.32
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.
3.33
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.
3.34
10 pipe sleeves were stockpiled against an
existing tree. The Contractor was
requested to remove immediately the stockpile away from the tree.
Environmental Site
Inspection
3.35
There were 13 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
3.36
No adverse observation was
identified in the reporting quarter.
Noise
3.37
No adverse observation was
identified in the reporting quarter.
Water Quality
3.38
Exposed earth was observed on
the slope at Row Y, Row Z, Row R and Row T. The Contractor was reminded to
clear the exposed earth.
3.39
Muddy water was observed
running down the u-channel along the site due to water-spraying to a soil nail
installation operation at Row T. The Contractor was reminded not to spray water
directly on exposed earth and make sure the effluent would be treated before
discharged to public drain.
3.40
Deposited silt was observed
accumulated inside the u-channel at Row T. The Contractor was requested to
clear the deposited silt more frequently.
Chemical and Waste Management
3.41
Oil drums at Row AA, Row AF and
Row AF10, and the soil nail installation controllers at Row AB, Row
AF10 and Row PD19 were found placed on ground without drip tray. The Contractor
was reminded to provide drip tray to all chemical containers and plants on
site.
3.42
Chemical containers were found
placed on ground without drip tray at Row AM, Row AN, Row AS, Row AT, Row AO,
Row AF, Row AP and Row AW. The Contractor was reminded to provide drip trays to
all chemical containers and dispose of the empty chemical containers as
chemical waste.
3.43
Oil stains were observed on
ground and over a drill rig at Row
AS. The Contractor was reminded
to clear the oil stains, dispose of as chemical waste and properly maintain the
plants on site to prevent leakage.
Ecology
3.44
A large number of metal rods
were randomly placed outside the soil nailing area. Some of them were merely supported by shrubs.
3.45
A heavy cable of the soil
nailing machine was found hanging on tree trunk and branch T6788 and T9795.
3.46
Trunks of trees located above Row AR
were not covered with warping for protection while site clearance and
scaffolding works were underway.
3.47
The fabric shield for soil
nailing works was found to be worn out and did not function properly to prevent
the dust generated during soil nailing works from affecting the vegetation
nearby.
3.48
Serious grout leakage was
recorded from Row AB to AQ and a large amount of tagged
vegetation of conservation interest was affected.
3.49
The boundary of a major site
access near Row AF was not clearly demarcated.
Landscape and Visual
3.50
Existing tree T611 could not be
saved by the Contractor and was dead.
The Contractor was recommended to seek Engineer’s agreement on the
replacement planting.
3.51
A couple of the dead trees,
including a tree with rotten trunk at the base located near existing tree T534,
had not been removed. The Contractor was recommended to remove all the dead and
rotten trees away from the footpath area for safety.
3.52
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.
3.53
Existing trees T516, T517,
T666, and T698 immediately outside the works area boundary were missing. The Contractor was requested to clarify the
status of the missing trees for information and record.
3.54
Construction waste was found
piled deep around existing tree T614.
The Contractor was requested to remove the construction waste around the
tree as soon as possible.
3.55
Several undersized existing
trees had been unnecessarily broken. The
Contractor was reminded to be more careful in order to minimize damage on trees
in future.
3.56
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.
3.57
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.
3.58
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.
3.59
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.
3.60
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.
3.61
10 pipe sleeves were stockpiled
against an existing tree. The Contractor
was requested to remove immediately the stockpile away from the tree.
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, 8.42 ton of inert
C&D waste was disposed offsite to Public Filling Barging Point at Quarry Bay
and 36.55 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
|
|
October 2008
|
November 2008
|
December 2008
|
Total
|
|
Complaint Logged
|
0
|
0
|
0
|
0
|
|
Summons
Served
|
0
|
0
|
0
|
0
|
|
Successful Prosecution
|
0
|
0
|
0
|
0
|
|
Total
|
0
|
0
|
0
|
0
|
Comments
on Mitigation Measures
7.1
According to the environmental
site inspections performed in the reporting quarter, the following recommendations
are provided:
Air Quality
-
N/A
Noise
-
N/A
Water Quality
-
Debris, leaves and deposited
silt inside the u-channel should be cleared more frequently.
-
Exposed earth at all working platforms
and slope should be cleared as soon as the soil nailing operation was
completed.
-
The
desilting tank next to Row D should be properly maintained.
-
Damaged sand bags on site
should be replaced.
-
Water for dust suppression
should avoid spraying directly on exposed earth and sediment.
Chemical and Waste Management
-
All plants and chemical
containers on site should be provided with drip tray.
-
Empty chemical containers
should be properly disposed of as chemical waste.
-
Water for dust suppression
should avoid spraying directly on exposed earth and sediment.
-
Cement
leakage should be avoided and cement slurry during
grouting works should be prevented from running off into u-channel.
Ecology
-
Construction material
including metal rods should be well supported by fixed storage devices but
not on trees within the works area.
-
The rubbish and plant
debris from site clearance should be removed from works area in a timely manner.
-
The spilt grout should be
removed from the tree trunk / root immediately.
-
All plant species of conservation
interest should be fenced off properly especially for those located near major
access road and areas likely to be impacted by construction activities.
-
Sand bag should be placed
over unpaved access road to avoid soil erosion and root damage.
-
Regular
watering should be carried out to wash dust covered on leaves of vegetation.
-
The Contractor was reminded
to take all necessary actions to prevent grout leakage to the surrounding
natural environment.
-
The fabric shields for soil
nailing works should be replaced regularly to ensure they function properly.
-
All site access should be
clearly demarcated and no excessive removal of vegetation in natural areas
adjacent to the site access should be allowed.
Landscape and Visual
-
All ineligible tree
identification numbers for all existing trees should be rectified.
-
The status of missing trees
should be clarified as soon as possible.
-
The Contractor was
recommended to seek Engineer’s agreement on the replacement planting for dead
tree.
-
All construction waste,
excavated materials and equipments should be kept away from existing tree and should
not be placed against trees.
-
Dead / rotten trees 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.
-
Unnecessary damage on
existing trees, especially the undersized trees, should be minimized.
-
Engineer’s agreement prior
to carry out tree pruning works should be sought and tree pruning works should only
be carried out by approved landscape contractor in future.
-
Damage to tree barks should
be avoided and better tree protections should be provided while carried out
works near vicinity of existing trees.
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 October 2008 to December 2008, 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.
