Civil Engineering Department
The Government of the Hong Kong
Special Administrative Region
Agreement No. CE 15/99
Demolition of Buildings and Structures
in the Proposed Kennedy Town
Comprehensive
Development Area Site
EM&A Manual
September 2001
Atkins
China Ltd
DOCUMENT TITLE PAGE
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Client : Civil
Engineering Department
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Contract No. (if any) : -
CE
15/99
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Project Title : Environmental Impact
Assessment for Demolition of Kwai Chung Incinerator
Plant and Kennedy Town CDA
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Project No. : 2996
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Document No. : 2996-OR028-04
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Controlled Copy No. :
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Covering Letter / Transmittal Ref. No. :
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Date of Issue :
September 2001
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Revision, Review and
Approval/Authorisation Records
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04
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5th Issue
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JWS/
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2nd Issue
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1st Issue
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Various/
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JWS/
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Revision
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Description
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Prepared by / date
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Reviewed by / date
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App. or Auth. By / date
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Distribution (if insufficient space, please use separate paper)
Controlled Copy No.
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Issued to
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1-45
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Civil Engineering Department
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46-47
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ACL – ELAN
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1.
INTRODUCTION
1.1.1
The purpose of
this Environmental Monitoring & Audit (EM&A) Manual is to guide the
EM&A programme for the Demolition of Buildings and Structures within the
Proposed Kennedy Town Comprehensive Development Area (KTCDA study brief
ESB-023/98) and to ensure compliance with the Environmental Impact Assessment
(EIA) Report. This is subject to
approval of the EIA Report under the statutory procedures of the EIAO and
supporting Technical Memorandum. The EIA
recommends procedures to:
·
Ensure that any
environmental impacts resulting from the demolition of the KTCDA are minimised
or kept to acceptable levels.
·
Check that
mitigation measures have been applied and are effective, and that the
appropriate corrective actions are undertaken, if and when required.
·
Provide a means
of checking compliance with environmental objectives, recording anomalies and
documenting corrective action.
1.1.2
This Manual
contains the following:
·
Information on
the KTCDA demolition project, the project organisation and construction
programme;
·
General EM&A
principles and the EM&A team organisation;
·
Monitoring
parameters, schedules, Action/Limit Levels and action plans;
·
Complaints
procedures.
·
Reporting
procedures.
1.1.3
As a general note
the IC(E) may be part of the Engineer’s Team, or may
be totally independent, employed under a separate contract by the project
proponent. In the latter case, this
Manual makes reference to items requiring agreement between the Contractor (or
his monitoring team), the engineers representative, relevant Government
departments and the IC(E). Attention is drawn to the
possibility of requiring agreement from a third party outside the contract in
the event that the IC(E) is employed independently.
1.2.1
The Criteria for
undertaking EM&A are provided by EPD, these are summarised as follows:
(a) to
protect sensitive receivers from environmental impacts if mitigation is not
implemented;
(b) to
protect the ecosystem;
(c) to
monitor activities in areas of high conservation value;
(d) to
monitor the effectiveness of mitigation measures which involves a long period
to establish;
(e) to
monitor any unproven technology;
(f) to
validate the hypothesis in analysis and design;
(g) to
audit the changing project scheduling; and
(h) others.
1.2.2
The conclusions
from the EIA indicate that Criterion a) is relevant with respect to the
possible impact excessive dust and noise may have on the sensitive receivers in
close proximity to the KTCDA.
1.2.3
Without
mitigation for dust and noise during the demolition phase, activities could
cause nuisance to the residents or occupants of the residential and some GI/C
facilities in the immediate vicinity.
The other criteria are not relevant to this project. On the basis of this interpretation of
Criterion a) an EM&A programme is recommended.
·
Kennedy Town Incineration Plant (KTIP);
·
Kennedy Town Abattoir (KTA);
·
New World First Bus Depot (NWFB);
·
Car / lorry park
(CP);
·
FEHD Refuse
Collection Point (RCP); and
·
Cadogan Street Temporary Garden (CSTG).
1.3.2
The structures to
be demolished are summarised in Table 1.1.
1.3.3
The KTCDA was
recommended for future private housing development in the “Planning and Engineering
Study for the Redevelopment of Mount Davis Cottage Area and Kennedy Town Police
Married Quarters” (Agreement No. CE 52/97), completed in
May1999. Under that study the
Open Space and Refuse Collection Point were proposed for relocation within the
redevelopment.
1.3.4
The proposed
Kennedy Town Development and Route 7 (R7), a strategic road link between Kennedy Town and Aberdeen, are located just to the north of the KTCDA site although the exact
alignment of R7 is not yet confirmed. A
further planning and engineering study to address some major issues, including
the Kennedy Town Development and alternative road alignments of Route 7, is
currently being considered by the government.
The findings from this further study may alter the future land use of the
KTCDA recommended in May 1999.
Table
1.1 Structures to be demolished at
KTCDA
Building
|
Brief Description
|
KTIP Chimneys
|
Two reinforced concrete chimneys, 60m
high, 3.5m in diameter.
|
KTIP Building
|
Reinforced concrete structure of approximately
3,025m² on plan
Refuse Pier
|
Kennedy Town Abattoir
|
5-storey reinforced concrete structures
of approximately 9,500m² on plan, including,
Reception Pier
|
E & M Services Department Building
|
Boiler House and Carcass Incinerator Building.
One reinforced concrete chimney, 25m
high, 3m in diameter.
|
New World First Bus Depot
|
Offices and Vehicle Inspection Bays.
Overall size is approximately 600m² on plan.
Diesel storage tank and lubrication oil
store.
|
Hong Kong Electric Sub Station
|
Single Storey Transformer House (adjacent
to lairage)
|
Cadogan Street Temporary Garden
|
Open landscaped area with street lighting
and sitting areas
|
Sai See Street Refuse Collection Point
|
Prefabricated steel and concrete
structure, single storey.
|
1.3.5
It has been
assumed that the demolition for KTCDA will take place as soon as possible in
order to allow future developments on and near the site. The start date is tentatively scheduled for
2003 with demolition works lasting about one year. Soil remediation may take another six to
eight months.
1.4.1
This section
identifies the sensitive receivers (SRs) affected by
the Project as defined in the EIAO and summarises the main implications of the SRs and infrastructure on demolition methods. Sensitive receivers and other constraints are
shown in Figure 1.1.
Sensitive Receivers at KTCDA
Residential,
Government, Institutional and Community
1.4.2
Residential,
Government, Institutional and Community uses surround the KTCDA site and many
are elevated and overlook the site. The
nearest rank of sensitive receivers is discussed below.
·
Kennedy Town
Police Married Quarters currently overlooks the site. The premises are scheduled to be vacated but
parts of the buildings will potentially be occupied up to March 2002.
·
The Mount Davis
Cottage Area has already been vacated.
·
The new Housing
Society development (Cayman Rise) at Ka Wai
Man Road is scheduled for
occupation by the 3rd quarter of 2001.
·
There are
occupied residential buildings at Cadogan Street including Centenary Mansion.
1.4.3
Other premises in
the low rise blocks in Cadogan Street (north of Victoria Road) haven been demolished.
1.4.4
Manhattan Heights high rise development at
Kennedy Town New Praya and some of the residential
units will overlook the site by the time demolition of KTCDA takes place.
1.4.5
There are other
residential blocks further west along Victoria Road (e.g. Huncliffe Court) that would be shielded by
the intervening structures such as the China Merchants Wharf Godown and other industrial buildings on Victoria Road.
1.4.6
There are
Government, Institutional and Community uses at St Lukes
Church School, St Lukes Settlement, Jockey Club
Clinic, Victoria Mortuary and the Bayanihan
Centre. St Lukes
Church School on Ka Wai Man Road and both St Lukes Settlement and Jockey Club Clinic will remain in
operation at the time of demolition for KTCDA.
The Bayanihan Centre on Victoria Road is a training and support
facility for Philippine overseas workers that is open
seven days per week and it is assumed this will remain in operation at the time
of the demolition of KTCDA.
NWFB
and RCP
1.4.7
The New World
First Bus Depot and the Refuse Collection Point may require relocation prior to
the demolition. However this is not
material to the EIA as neither are defined as SRs.
Road Traffic
Other
Issues
1.4.8
The revised
alignment for Route 7 and the extent of the Kennedy Town Development are
currently under review but at present the programme of these developments is
unlikely to be advanced before year 2002 and after the target completion date
for demolition of KTCDA. At this stage
these proposals are not thought to have any impact on the Project.
1.4.9
Based on initial
site investigations and according to the building drawings for the Sites
records, some asbestos containing materials (ACM) are present at KTCDA. The
asbestos investigation and abatement plans are described in detail in the
dedicated Asbestos Study Report.
Asbestos abatement will take place in line with the requirements of the
APCO and codes of practice.
General Approach
1.5.1
This section
presents general procedures for demolition, which would be likely to apply to
KTCDA to illustrate the agreed methodology which has been used to progress the
Environmental Impact Assessment.
1.5.2
Whereas the
eventual detailed demolition plan of the selected demolition Contractor(s) may
not necessarily adopt the precise methodology proposed in WP1 and summarised
here, the consultants believe that general characteristics of the methods are
appropriate. Blasting will not be used
and other conventional methods are sufficiently effective and applicable for
the tasks. Where possible methods that
will help reduce noise and dust nuisances have been chosen. The options selected are also broadly in line
with the Draft Code of Practice for Demolition of Buildings (Buildings
Department 1998) which will also need to be observed at the detailed design stage.
1.5.3
The overriding
concerns for the demolition Project will be safety and minimisation of
environmental impacts. This will include
the safety of the operatives, safety of the other workers on the site and
safety of the general public as well as protection of adjacent facilities and
minimisation of nuisances. The
Contractor shall also, during the course of demolition, ensure and verify that
all utilities and services have been rendered safe.
Hoarding and Site Access
1.5.4
The typical site
hoarding will be modified in to a perimeter noise barrier as shown in Figure
1.2. Portable barricades will be used to
cordon off different work zones within the site. All structures are totally within the
proposed Project sites and access would be controlled by security guards. No members of the public or unauthorised
person would be allowed entry to the site.
Only Contractors’ personnel and Government officials would be allowed
within the Contractor’s working area.
General Demolition Principles
1.5.5
Demolition of
building and structures would generally be in the reverse order to that of
construction, progressive, storey by storey, having regard to type of
construction. Wherever possible,
external non-loading bearing cladding should be removed first. All asbestos containing
materials (ACM, particularly any ACM panels, would be removed prior to
commencement of demolition works where ever possible. Other ACM may need to be removed as access is
gained to particular areas and as the demolition progresses.
General Safety Measures
1.5.6
The Contractor
will need to carry out works in accordance with the Factories and Industrial
Undertakings Ordinance, particularly the Construction Site (Safety) Regulations
and the Code of Practice for Scaffold Safety, as well as all other statutory
requirements and guidelines covering health and safety issues.
1.5.7
The Contractor
shall arrange for a competent scaffolder to visit
site and inspect the scaffolding work, and to make any adjustments as the work
proceeds, to ensure its stability.
1.5.8
The Contractor
should ensure that every work place, approach and opening, which may pose a
danger to persons employed and others should be properly illuminated and
protected.
1.5.9
The use of all
mobile cranes must be strictly controlled to ensure that cranes of adequate
capacity will be used for lifting under different loading conditions.
General Approach
1.6.1
The area beneath
the chimneys would be cordoned off and only authorised staff involved in the
demolition of the chimneys would be allowed admission into the vicinity of the
chimney structures.
1.6.2
The concrete
weather shield and the flues will be removed manually. The principle of the demolition procedure
shall be that the chimney and flues would be cut into pieces and these pieces
lowered to ground level inside the chimney.
This method would ensure that full control the fall of the debris and
that the pieces of reinforced concrete are not left to free fall outside the
chimney.
1.6.3
The principle of
the demolition procedure for the upper portion of the chimneys (i.e. say
10metres from ground level or greater) is that the chimneys will be broken into
small pieces on the spot by operatives using hand held tools. They would work from working platforms
external to the chimney. Hydraulic
breakers would be used for the remaining lower portions of the chimneys.
1.7.1
The areas
requiring decontamination, identified based on the
Contamination Assessment Report and Remediation Action Plan are
shown in Figure 6.1.
1.8.1
The EIA recommended
a range of mitigation measures to control the demolition Project’s potential
construction environmental impacts, which include dust and noise impacts. The schedule of mitigation measures is
provided in Section 7 of this Manual.
1.9.2
The preferred
approach is for the Independent Environmental Monitoring Team (ET) to be
employed directly by the project proponent (CED). The monitoring is audited and checked by the
Environmental Monitoring Team Leader (ETL) who reports to the Engineer’s
Representative (ER).
1.9.3
Independent
Monitoring Team Leader (ETL): This person should be
professionally qualified with suitable experience in environmental management
and planning. As a general
recommendation, 7 years’ experience is desirable, although if the proposed ETL
has less, agreement should be sought from the ER. Extensive knowledge of the study area is
required. The ETL should have work
experience in Hong Kong managing and providing
specialist advice on environmental monitoring of infrastructure projects.
1.9.4
Site
Inspection Team Leader: Requires experience working
on environmental projects in Hong Kong. Extensive experience in
dealing directly with Contractors is required.
1.9.5
Noise/Air
Specialist: Requires experience in the air and
noise pollution field. Skills in the use of computer models, database design
and management of monitoring programmes are required.
1.9.6
Consultant: Experience as an environmental consultant with a broad range of
expertise both in the technical and managerial aspects of environmental
assessment. Proficient in: water quality
sampling, analysis and assessment; air and noise monitoring, modelling and
analysis; site assessment; and scoping exercises to identify key environmental
issues.
1.9.7
Assistant
Consultant: Experience in conducting on-site
monitoring, data-gathering and subsequent computer-modelling data analyses.
1.9.8
The duties to be
undertaken by the Environmental Team (ET) comprise the following:
·
sampling, analysis and statistical
evaluation of monitoring parameters with reference to the EIA Study
recommendations and requirements.
·
environmental
site surveillance;
·
audit of
compliance with environmental protection and pollution prevention and control
regulations;
·
monitor the
implementation of the environmental mitigation;
·
monitor
compliance with the environmental protection clauses/specifications in the
Contract;
·
review
construction (demolition) programme and comment as necessary;
·
review
construction (demolition) methodology and comments as necessary;
·
complaint
investigation , evaluation and identification of corrective measures;
·
liaison with
IC(E) on environmental performance matters and submission of EM&A
deliverables to IC(E) for approval; and
·
advise on environmental improvement
and enhancement.
1.9.9
Appropriate
resources shall be allocated by the ET to fulfil the duties specified in this
Manual.
1.9.10
Independent Checker (Environment). The role of the IC(E) shall be independent from the management of
construction works; but the IC(E) shall be empowered to audit the environmental
performance of construction (Appendix B).
The IC(E) shall have a similar of level of
experience as the ETL.
1.10.2
The buildings and
chimneys at KTCDA can be demolished and removed by conventional top down
demolition using hand held tools and mechanical breaking methods. Professional experience and consultation with
local contractors indicates that the estimated time for the completion of these
works of 12 months would appear to be ample time for demolition based on the
above methodology. The chimney
demolition would follow demolition of the main buildings. The EM&A programme will also cover the
soil remediation phase, which will be undertaken following the demolition of
structures which may last another six to eight months.
1.10.3
Whereas the
demolition programme has yet to be established in detail, the implementation of
acoustic mitigation measures such as use of silenced equipment and acoustic
barriers is routine in Hong Kong nowadays. Likewise there
will be statutory requirements for mitigation of fugitive dust emissions under
the APCO. Whereas these should not have
any significant impact on the, programme providing the requirements are
recognised early as will be the case through the environmental permit, the
Contractors will be expected to allow for such resources in their responses to
tender.
Table
1.1 Structures to be demolished at
KTCDA
Building
|
Brief Description
|
KTIP Chimneys
|
Two reinforced concrete chimneys, 60m
high, 3.5m in diameter.
|
KTIP Building
|
Reinforced concrete structure of approximately
3,025m² on plan
Refuse Pier
|
Kennedy Town Abattoir
|
5-storey reinforced concrete structures of
approximately 9,500m² on plan, including,
Reception Pier
|
E & M Services Department Building
|
Boiler House and Carcass Incinerator Building.
One reinforced concrete chimney, 25m high, 3m in
diameter.
|
New
World First Bus Depot
|
Offices and Vehicle Inspection Bays. Overall size is
approximately 600m² on plan.
Diesel storage tank and lubrication oil store.
|
Hong
Kong Electric Sub Station
|
Single Storey Transformer House (adjacent to lairage)
|
Cadogan Street Temporary Garden
|
Open landscaped area with street lighting and
sitting areas
|
Sai
See Street Refuse Collection Point
|
Prefabricated steel and concrete structure, single
storey. *
|
2.1.1
Monitoring and
audit of Total Suspended Particulates (TSP) levels shall be carried out by the
ET to ensure that any deteriorating air quality can be readily detected and
timely action taken to rectify the situation.
2.2.1
1-hour and
24-hour TSP levels shall be measured to indicate the impacts of construction
dust on air quality. The TSP levels
shall be measured by following the standard high volume sampling method as set
out in Title 40 of the American Code of Federal Regulations, Chapter 1 (Part
50), Appendix B.
Upon approval of the ER, 1-hour TSP levels shall alternatively be
measured by direct reading methods to indicate short event impacts which are
capable of producing comparable results as that obtained by the high volume
sampling method.
2.2.2
All relevant data
including temperature, pressure, weather conditions, elapsed-time meter reading
for the start and stop of the sampler, identification and weight of the filter
paper, and other special phenomena and work progress of the concerned site etc.
shall be recorded in detail. A sample
data sheet is shown in Table 2.4.
2.3.1
High volume
samplers (HVS) to be used for carrying out the 1-hr and 24-hr TSP monitoring
shall comply with the following specifications:
·
0.6-1.7 m3/min
(20-60 SCFM) adjustable flow range;
·
Equipped with a
timing/control device with +/- 5 minutes accuracy for 24 hours operation;
·
Installed with
elapsed-time meter with +/- 2 minutes accuracy for 24 hours operation;
·
Capable of
providing a minimum exposed area of 406 cm2 (63 in2);
·
Flow control
accuracy: +/- 2.5% deviation over 24-hr sampling period;
·
Equipped with a
shelter to protect the filter and sampler;
·
Incorporated with
an electronic mass flow rate controller or other equivalent devices;
·
Equipped with a
flow recorder for continuous monitoring;
·
Provided with a
peaked roof inlet;
·
Incorporated with
a manometer;
·
Able to hold and
seal the filter paper to the sampler housing at horizontal position;
·
Easy to change
the filter; and
·
Capable of operating
continuously for 24-hr period.
2.3.2
The ET shall
provide sufficient equipment to ensure that the monitoring commences on
schedule and is not interrupted as a result of equipment failure, damage, loss
or routine maintenance.
2.3.3
The HVSs shall be equipped with an electronic mass flow
controller and be calibrated against a traceable standard at regular intervals.
All the equipment, calibration kit, filter papers, etc. shall be clearly
labelled.
2.3.4
Initial
calibration of dust monitoring equipment shall be conducted upon installation
and thereafter at bi-monthly intervals.
The transfer standard shall be traceable to the internationally
recognised primary standard and be calibrated annually. The calibration data
shall be properly documented for future reference. All the data shall be converted into standard
temperature and pressure conditions.
2.3.5
The flow-rate of
the sampler before and after the sampling exercise with the filter in position
shall be verified to be constant and be recorded in the data sheet (Table 2.4).
2.3.6
If the ET uses a
direct reading dust meter to measure 1-hr TSP levels, he shall submit
sufficient information to the ER including calibration standards to demonstrate
that the instrument is suitable for the monitoring task. The instrument shall also be calibrated
regularly, and the 1-hr sampling shall be determined periodically by HVS to
check the validity and accuracy of the results measured by direct reading
method.
2.3.7
The ET shall
provide sufficient wind data monitoring equipment to ensure that the monitoring
commences on schedule and is not interrupted as a result of equipment failure,
damage, loss or routine maintenance.
2.4.1
A clean
laboratory with constant temperature and humidity control, equipped with
necessary measuring and conditioning instruments, to handle the dust samples
collected, shall be available for sample analysis, equipment calibration and
maintenance.
2.4.2
If a site
laboratory is set up or a non-HOKLAS accredited laboratory is hired for
carrying out the laboratory analysis, the laboratory equipment shall be
approved by the ER and the measurement procedures shall be witnessed by the
ER. The ET shall provide the ER with one
copy of Title 40 of the American Code of Federal Regulations, Chapter 1 (Part
50), Appendix B for his reference.
2.4.3
Filter paper of
size 8”x10” shall be labelled before sampling. It shall be a clean filter paper
with no folds or pin holes, and shall be conditioned in a humidity controlled
chamber for over 24-hr and be pre-weighed before sampling.
2.4.4
After sampling,
the filter paper loaded with dust shall be kept in a clean and tightly sealed
plastic bag. The filter paper will then
be returned to the laboratory for reconditioning in the humidity control
chamber followed by accurate weighing by an electronic balance to the nearest
0.1mg. The balance shall be regularly
calibrated against a traceable standard.
2.4.5
All the collected
samples shall be retained and kept in a good condition for 6 months before
disposal.
2.5.1
The dust
sensitive receivers are shown in Figure 1.1.
These include the following:
Existing Sensitive Receivers:
·
Serene Court
·
Regent Heights Towers
·
Huncliffe Court
·
Cheong Kat Mansion
·
Centenary Mansion
·
Sai Wan Estate
·
Bayanihan Centre
·
Jockey Club Clinic
(JCC)
·
St. Luke’s Church
and Lui Ming Choi Memorial Primary School
·
Sai Wan New Apartments
·
Kennedy Mansion and
·
Cheong Kat Building
Future Receivers:
·
Future URA
Development
·
Hong Kong Housing
Society Residential Development (Cayman Rise)
·
Proposed Residential
Development, Sai Wing Street
·
Manhattan Heights.
2.5.2
The status and locations of dust sensitive
receivers may be revised after issue. The ET shall identify the SR locations to
be adopted based on the updated construction programme and seek approval from
the ER and relevant government departments.
Monitoring Locations
2.5.3
The monitoring
locations should meet the following criteria:
·
A horizontal
platform with appropriate support to secure the samplers against gusty wind
shall be provided;
·
No two samplers
shall be placed less than 2 metres apart;
·
The distance
between the sampler and an obstacle, such as buildings, must be at least twice
the height that the obstacle protrudes above the sampler;
·
A minimum of 2
metres of separation from walls, parapets and penthouses is required for
rooftop samplers;
·
A minimum of 2
metre separation, measured horizontally, from any supporting structure, is
required;
·
No furnace or
incinerator flues shall be nearby;
·
Airflow around
the sampler shall be unrestricted;
·
The sampler shall
be more than 20 metres from the dripline;
·
Any wire fence
and gate, to protect the sampler, shall not cause any obstruction during
monitoring;
·
Permission must
be obtained to set up the samplers and to obtain access to the monitoring
stations; and
·
A secured supply
of electricity will be needed to operate the samplers.
2.5.4
In general,
monitoring should be undertaken at sensitive receivers. However, as it cannot be guaranteed that
permission to monitor at privately owned locations will be forthcoming (and
hence to avoid delays in organising the monitoring programme and contractual
difficulties), monitoring may be undertaken at alternative locations such as
the site boundary, where necessary.
Suggested locations are shown on Figure 2.1.
2.5.5
The criteria for
locating samplers shall be as follows, as far as practicable:
·
take into
consideration the prevailing meteorological conditions;
·
at the site
boundary or such locations close to the major dust emission source; and
·
as close to the sensitive receivers
as possible to reflect conditions at the sensitive receivers.
2.6.1
The ET shall
carry out baseline monitoring as close as is practical to sensitive receivers
as recommended above. It is recommended
that 2 locations are selected for baseline monitoring around the site
areas. The suggested initial locations
are given in Figure 2.1.
2.6.2
The exact
locations shall be agreed with the ER and relevant government departments prior
to commencement of the monitoring programme.
2.6.3
Monitoring shall
be for 14 consecutive days at two locations prior to the commissioning of the
construction works to obtain daily 24-hr TSP samples (total of 28, 24-hour
average measurements). 1-hr per day
sampling shall also be completed for 14 days at each location (total of 84,
1-hour average measurements).
2.6.4
During the
baseline monitoring programme, there shall be no construction activity or dust
generation activities in the vicinity of the monitoring stations which may
affect the monitoring results.
2.6.5
In exceptional
cases, when insufficient baseline monitoring data or questionable results are
obtained, the ETL shall liaise with the ER to agree on an appropriate set of
data to be used as a baseline reference and submit to ER and relevant
government departments for approval.
2.6.6
Ambient conditions
may vary seasonally and shall be reviewed at three monthly intervals. If the ETL considers that the ambient
conditions have changed and a repeat of the baseline monitoring is required for
obtaining the updated baseline levels, the monitoring shall be, at times when
the Contractor’s activities are not generating dust, at least in the proximity
of the monitoring stations. Should a
change in ambient conditions be determined, the baseline levels and, in turn,
the air quality criteria, shall be revised.
The revised baseline levels and air quality criteria shall be agreed
with ER and relevant government departments.
Construction Dust
2.7.1
The ET shall
carry out regular impact monitoring during the course of the Works. Monitoring
shall be undertaken at 2 stations for 24-hr TSP monitoring. A sampling frequency of one 24 hour
measurement every six-days at 2 stations shall be adopted. For 1-hour TSP monitoring, a sampling frequency
of at least three times in every six days shall be undertaken.
2.7.2
In case of
non-compliance with the air quality criteria, more frequent monitoring shall be
conducted within 24 hours of the non-compliance. This is specified in the Event Action Plan
(see below). Further monitoring shall be
continued until the excessive dust emission or the deterioration in air quality
is rectified.
Airborne Fibre Monitoring
2.7.3
The ET shall also
ensure that airborne fibre monitoring is carried out by a HOKLAS accredited
Registered Asbestos Laboratory in line with the Requirements of the AAP. In addition regular airborne fibre monitoring
shall be carried out daily at the boundary of the site during the course of the
Asbestos Works as required by EPD.
Airborne Fibre Monitoring shall be undertaken at a minimum of 3 stations
daily at locations to be confirmed with EPD.
Suggested locations for the Airborne Fibre Monitoring are presented in
Figure 2.2.
2.8.1
The baseline monitoring results form the basis for determining the
air quality criteria for the impact monitoring. The ETL shall compare the impact monitoring
results with air quality criteria set up for 24-hour TSP and 1-hr TSP. Table 2.1 shows the air quality criteria,
namely Action and Limit levels to be used.
Should non-compliance with the air quality criteria occur, the ET, the
ER and the Contractor shall undertake the relevant action in accordance with
the Event Action Plan in Table 2.2.
Table 2.1 Action
and Limit Levels for Air Quality
Parameters
|
Action
|
Limit*
|
24 Hour TSP
Level in mg/m3
|
For baseline
level < 200 mg/m Action level =
(Baseline level * 1.3 + Limit level)/2;
For baseline level > 200 mg/m Action level = Limit level
|
260
|
1 Hour TSP Level
in mg/m3
|
For baseline
level < 384 mg/m Action Level = (Baseline level * 1.3 +
Limit level)/2;
For baseline level > 384 mg/m Action level = Limit level
|
500
|
Airborne fiblre level in fibres/ml
|
0.006 f/ml
|
0.01
|
Table 2.2 Event/Action
Plan for Air Quality
|
|
|
ACTION
|
EVENT
|
ET
|
IC(E)
|
ER
|
CONTRACTOR
|
ACTION LEVEL
|
1. Exceedance for one
sample
|
1. Identify source
2. Inform (C(E) and ER
3. Repeat measurement to confirm finding
4. Increase monitoring frequency to daily
|
1. Check
monitoring data submitted by ET
2. Check
Contractor’s working method
|
1. Notify Contractor
2. Check monitoring data and Contractor's
working methods
|
1. Rectify
any unacceptable practice
2. Amend
working methods if appropriate
|
2. Exceedance for two
or more consecutive samples
|
1. Identify source
2. Inform IC(E) and ER
3. Repeat measurements to confirm findings
4. Increase monitoring frequency to daily
5. Discuss with Contractor , IC(E) and ER for
remedial actions required
6. If exceedance
continues, arrange meeting with IC(E) and ER
7. If exceedance
stops, cease additional monitoring
|
1. Checking
monitoring data submitted by ET
2. Check
Contractor’s working method
3. Discuss
with ET and Contractor on possible remedial measures
4. Advise
the ER on the effectiveness of the proposed remedial measures
5. Supervise
implementation of remedial measures
|
1. Confirm receipt of notification of failure in
writing
2. Notify Contractor
3. Check monitoring data and Contractor's
working methods
4. Discuss with IC(E) and Contractor on
potential remedial actions
5. Ensure remedial actions properly implemented
|
1. Submit
proposals for remedial actions to ER within 3 working days of notification
2. Implement
the agreed proposals
3. Amend
proposal if appropriate
|
LIMIT LEVEL
|
1. Exceedance for one
sample
|
1. Identify
source
2. Inform
ER and EPD
3. Repeat
measurement to confirm finding
4. Increase
monitoring frequency to daily
5. Assess
effectiveness of Contractor's remedial actions and keep IC(E), EPD and ER
informed of the results
|
1. Checking
monitoring data submitted by ET
2. Check
Contractor’s working method
3. Discuss
with ET and Contractor on possible remedial measures
4. Advise
the ER on the effectiveness of the proposed remedial measures
5. Supervisor
implementation of remedial measures
|
1. Confirm receipt of notification of failure in
writing
2. Notify Contractor
3. Check monitoring data and Contractor's
working methods
4. Discuss with ET Leader and Contractor
potential remedial actions
5. Ensure remedial actions properly implemented
|
1. Take
immediate action to avoid further exceedance
2. Submit
proposals for remedial actions to ER within 3 working days of notification
3. Implement
the agreed proposals
4. Amend
proposal if appropriate
|
2. Exceedance for two
or more consecutive samples
|
1. Identify
source
2. Inform
IC(E), ER and EPD the causes & actions taken for the exceedances
3. Repeat
measurement to confirm findings
4. Increase
monitoring frequency to daily
5. Investigate
the causes of exceedance, Contractor’s working
procedures to identify possible mitigation
6. Arrange
meeting with IC(E) and ER to discuss the remedial actions to be taken
7. Assess
effectiveness of Contractor's remedial actions and keep IC(E), EPD and ER
informed of the results
8. If
exceedance stops, cease additional monitoring
|
1. Discuss
amongst ER, ET and Contractor as the potential remedial actions
2. Review
Contractor’s remedial actions whenever necessary to ensure their
effectiveness and advise the ER accordingly
3 Supervise
the implementation of remedial measures
|
1. Confirm receipt of notification of failure in
writing
2. Notify Contractor
3. Carry out analysis of Contractor's working
procedures with IC(E) to determine possible mitigation to be implemented
4. Discuss amongst Environmental Team Leader and
the Contractor potential remedial actions
5. Review Contractor's remedial actions whenever
necessary to assure their effectiveness
6. If exceedance
continues, consider what portion of the work is responsible and instruct the
Contractor to stop that portion of work until the exceedance
is abated
|
1. Take
immediate action to avoid further exceedance
2. Submit
proposals for remedial actions to ER within 3 working days of notification
3. Implement
the agreed proposals
4. Resubmit
proposals if problem still not under control
5. Stop
the relevant portion of works as determined by the ER until the exceedance is abated
|
2.9.1
The EIA has
discussed in general terms the appropriate dust control and mitigation
measures, these are provided in more detail below. The Contractor shall adopt all measures as
required under the Air Pollution Control (Construction Dust) Regulations and
implement dust suppression measures which shall include, but not be limited to,
the following:-
·
Stockpiles of
dusty waste materials greater than 20m3 shall be enclosed on three
sides, with walls extending above the pile and 2 metres beyond the front of the
pile.
·
Any vehicle with
an open load carrying area used for moving potentially dusty material shall
have properly fitting side and tail-boards.
Materials having the potential to create dust shall not be loaded to a
level higher than the side and tail boards and shall be covered by a clean
tarpaulin in good condition. The
tarpaulin shall be properly secured and shall extend at least 300mm over the
edges of the side and tail-boards.
·
Effective water
sprays shall be used during the collection and loading of dusty wastes and
other similar materials, when dust is likely to be created and to dampen all
stored materials during dry and windy weather.
·
Areas within the
Site where there is a regular movement of vehicles, shall have an approved hard
surface and be kept clean of loose surface material.
·
Conveyor belts
shall be fitted with wind-boards, and conveyor transfer points and hopper
discharge areas shall be enclosed to minimise dust emission. All conveyors carrying materials which have
the potential to create dust shall be totally enclosed and fitted with belt
cleaners.
·
Adequate dust
suppression plant including water bowsers with spray
bars shall be provided.
·
Unless otherwise
approved by the ER the Contractor shall restrict all motorised vehicles on the
Site to a maximum speed of 15 km per hour and confine haulage and waste
collection vehicles to designated roadways inside the Site.
2.9.2
If the above
measures are not sufficient to restore the air quality to acceptable levels
upon the advice of ETL, the Contractor shall liaise with the ETL on some other
mitigation measures, propose to ER for approval, and implement the mitigation
measures.
2.9.3
Using the
above-mentioned measures and requirements in the Air Pollution Control
(Construction Dust) Regulation, the dust nuisance to the surroundings shall be
minimised. In addition, the
Environmental Monitoring and Audit (EM&A) for dust generated during the
demolition is also recommended at the site boundary at the west to ensure that
the dust criteria will not be exceeded.
2.9.4
The Contractor
shall implement dust suppression measures as identified in the Schedule given
in Section 8.
Table
2.3 Data Sheet for TSP Monitoring
Monitoring
Location
|
Details
of Location
|
Sampler
Identification
|
Date
& Time of Sampling
|
Elapsed-time
|
Start
(min.)
|
Meter
Reading
|
Stop
(min.)
|
Total
Sampling Time (min.)
|
Weather
Conditions
|
Site
Conditions
|
|
Pi (mmHg)
|
Initial Flow
Rate, Qsi
|
Ti (oC)
|
|
Hi (in.)
|
|
Qsi (Std. m3)
|
|
Pf (mmHg)
|
Final Flow
Rate, Qsf
|
Tf (oC)
|
|
Hf (in.)
|
|
Qsf (Std. m3)
|
Average Flow
Rate (Std. M3)
|
Total Volume (Std. m3)
|
Filter Identification
No.
|
Initial Wt.
Of Filter (g)
|
Final Wt. Of
Filter (g)
|
Measured TSP
Level (µg/m3)
|
|
|
Name & Designation
|
|
Signature
|
|
Date
|
Field
Operator
|
:
|
|
|
|
|
|
Laboratory Staff
|
:
|
|
|
|
|
|
Checked by
|
:
|
|
|
|
|
|
3.
Noise
3.1.1
EM&A
procedures for noise are recommended to ensure that the necessary controls are
implemented effectively and that the noise criteria are not exceeded.
3.2.1
The construction
(demolition) noise level shall be measured in terms of the A-weighted
equivalent continuous sound pressure level (Leq). Leq (30
min) shall be used as the monitoring
parameter for the time period between 0700-1900 hours on normal weekdays. For all other time periods, Leq (5 min) shall be employed for comparison with the Noise
Control Ordinance (NCO) criteria.
3.2.2
As supplementary
information for data auditing, statistical results such as L10 and L90
shall also be obtained for reference. A
sample data record sheet is shown in Table 3.4 is included for reference.
3.3.1
As referred to in
the Technical Memorandum (TM) issued under the Noise Control Ordinance (NCO),
sound level meters in compliance with the International Electrotechnical
Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1)
specifications shall be used for carrying out the noise monitoring. Immediately
prior to and following each noise measurement the accuracy of the sound level
meter shall be checked using an acoustic calibrator generating a known sound
pressure level at a known frequency. Measurements shall be accepted as valid
only if the calibration level from before and after the noise
measurement agree to within 1.0dB.
3.3.2
Noise
measurements shall be made in accordance with standard acoustical principles
and practices in relation to the prevailing conditions. Noise measurements shall not be made the
presence of fog, rain, wind with a steady speed exceeding 5 ms-1 or
wind with gusts exceeding 10 ms-1.
The wind speed shall be checked with a portable wind speed meter capable
of measuring the wind speed in ms-1.
3.3.3
The ET is
responsible for the provision of the monitoring equipment. He shall ensure that
sufficient noise measuring equipment and associated instrumentation are
available for carrying out the baseline monitoring, regular impact monitoring
and ad hoc monitoring. All the equipment and associated instrumentation shall
be clearly labelled.
3.4.1
The noise sensitive receivers are shown in Figure 1.1. The monitoring locations are shown in Figure 3.1.
3.4.2
The status and locations of noise sensitive
receivers may require review after issuing this manual. It is proposed that the ET shall revise the
monitoring locations to be adopted based on prevailing conditions. These shall be agreed with the ER, IC(E) and relevant government departments.
3.4.3
Monitoring
locations shall be based on the following criteria:
·
at locations
close to the major site activities which are likely to have noise impacts; and
·
close to the noise sensitive
receivers.
3.4.4
Monitoring
locations located in the vicinity of the sensitive receivers must be operated
with care to ensure minimal disturbance to the occupants during
monitoring. Monitoring at SRs premises also introduces a complication for the
implementation of the baseline monitoring of permission and access at the SRs cannot be confirmed in time. Therefore in this case it
is recommended that monitoring be undertaken at the site boundary, just inside
the site hoarding, in an area under the control of the project proponent. This will ensure a conservative
approach.
3.4.5
The following
locations are identified as suitable monitoring locations Figure 2.1):
·
Site Boundary
opposite Jockey Club Clinic/St. Luke’s Church and Lui Ming Choi Memorial Primary School *
·
Site boundary east of KTIP
·
Site boundary
opposite future UPA Development in Cadogan Street, Sai Wan New Apartments, Kennedy Mansion and Cheong Kat Building
3.4.6
The sensitive
receivers are sufficiently close by and for purposes of baseline monitoring
purposes, three locations should be monitored.
3.4.7
Preliminary
proposed monitoring locations are shown in Figure 3.1. Each monitoring station shall normally be at
a position 1.2m above the ground, just inside the site hoarding. If there is a problem with access to the
normal monitoring position, an alternative position may be chosen, and a
correction to the measurements shall be made.
For reference, a correction of +3dB(A) shall be
made to the free field measurements.
3.4.8
The ETL shall
agree with the ER, the monitoring position and the corrections to be
adopted. Once the positions for the
monitoring stations are chosen, the baseline monitoring and the impact
monitoring shall be carried out at the same positions.
3.5.1
The ETL shall
carry out baseline noise monitoring prior to the commencement of the
construction works. The baseline
monitoring shall be carried out for 14 days at locations to the proposed
positions to the east, south and west of the site.
3.5.2
During
non-restricted hours (07:00 to 19;00) the measured parameter will be Leq 30 minutes and the baseline
monitoring shall be carried out for three half hour periods per day at each of
the three identified locations for a period of 14 days. A schedule on the baseline monitoring shall
be submitted to the ER for approval before the monitoring starts. Total numbers of required Leq
30 minutes samples shall be 42.
3.5.3
There shall not
be any abnormal activities in the vicinity of the monitoring stations during
the baseline monitoring which would cause the monitoring results to be elevated
above normal background conditions.
3.5.4
In exceptional
cases, when insufficient baseline monitoring data or questionable results are
obtained, the ETL shall liaise with EPD to agree on an appropriate set of data
to be used as a baseline reference for approval.
3.6.1
Noise monitoring
shall be carried out at 3 locations per week.
The monitoring frequency shall depend on the scale of the construction
activities. The following defines the
regular monitoring frequency for 3 stations on a per week basis when noise
generating activities are underway:
a) One set of measurements between 0700-1900 hours on normal weekdays
b) One set of measurements between 1900-2300 hours (if evening
activities are undertaken)
c) One set of measurements between 2300-0700 hours next day (if there
are night activities).
d) One set of measurements between 0700-1900 hours on holidays (if work
is undertaken)
3.6.2
For measurements
b), c) and d) above, one set of measurements shall at least include 3
consecutive Leq (5 min) results.
3.6.3
As demolition
activity is likely to take place near one primary school, noise monitoring
shall be carried out at a monitoring station near the school during examination
periods. The ETL shall liaise with the
school staff and the Examination Authority to ascertain the exact dates and
times of all examination periods during the course of the contract.
3.6.4
In case of
non-compliance with the construction noise criteria, more frequent monitoring
may be required in line with the Event Action Plan. This additional monitoring shall be continued
until the recorded noise levels are rectified or proved to be unrelated to the
demolition activities.
3.7.1
The Action and
Limit levels for construction noise are defined in Table 3.1. Should
non-compliance of the criteria occur, action in accordance with the Action Plan
in Table 3.2, shall be carried out.
Table 3.1 Action
and Limit Levels for Construction Noise
Time Period
|
Action
|
Limit
|
0700-1900
hrs on normal weekdays
|
|
75*dB(A)
|
0700-2300
hrs on holidays; and 1900-2300 hrs on all other days
|
When one
documented complaint is received
|
60/65/70**dB(A)
|
2300-0700
hrs of next day
|
|
45/50/55**dB(A)
|
* reduce to 70dB(A) for schools
and 65 dB (A) during school examination periods.
** to be selected based on Area
Sensitivity Rating as defined under the Noise Control Ordinance.
3.8.1
The EIA has
discussed the noise mitigation measures in general terms. These are given in more detail below. Noise mitigation measures are identified in
Section 10.
3.8.2
The Contractor
shall consider noise as an environmental constraint in his planning and execution
of the Works.
3.8.3
The Contractor
shall take all necessary measures to ensure that the operation of all
mechanical equipment and construction processes on or off the Site shall not
cause any unnecessary and excessive noise which may disturb any occupant of any
nearby dwellings, schools, clinic, or premises with sensitivity to noise. Prior to commencement of demolition
activities, the Contractor shall submit to the ER for his approval details of
all Construction Plant, including methods of use and construction operations,
together with proposed measures for limiting noise. These shall include, but not be limited to,
the likely location of noise-emitting plant, the use of silencers, mufflers,
acoustic sheds, shields, or screens and shall be based upon the best reasonable
practice. Information on the types and
models of silenced equipment and acoustic treatment for unsilenced
equipment shall be included. The
Contractor shall use all such measures and shall maintain all plant and
silencing equipment in good condition so as to minimise the noise emission
during construction works.
3.8.4
The Contractor’s
attention is drawn to all Regulations made under the Noise Control Ordinance.
Those currently in force are :-
·
Noise Control
(Hand Held Percussive Breakers) Regulations
·
Noise Control
(Air Compressors) Regulations
·
Noise Control
(Hearing Protection) Regulations
·
The Factories and
Industrial Undertakings (Noise at Work) Regulations are also applicable.
3.8.5
The Contractor shall
be responsible for obtaining Construction Noise Permits (CNPs)
from EPD as required for his operations.
The locations of Noise Sensitive Receivers (NSRs)
are indicated in Clause 3.3 of this manual, but the Contractor for obtaining
and complying with EPD’s requirements regarding
identification of any additional NSRs and conditions
attached to CNPs.
All correspondence with EPD and each issued CNP shall be copied to the
ER and IC(E).
3.8.6
The Contractor’s
attention shall be drawn to the fact that other construction work in the
vicinity of the Site will be taken into account by EPD in assessing
applications for CNP.
3.8.7
The Contractor
shall arrange methods of working to minimise noise impacts, and shall provide
experienced personnel to ensure that these methods are implemented.
3.8.8
If after
commencement of the Works the Construction Plant, equipment, or methods of
working are believed by the ER to be causing serious noise pollution impacts,
they shall be inspected and remedial proposals drawn up by the Contractor, consented to by the ER and implemented. In
developing these remedial measures, the Contractor will be expected to review
all construction noise sources that may be contributing to the pollution
impacts in order to achieve an overall reduction of cumulative noise
impacts. The Contractor will propose
changes to plant locations and scheduling of activities, installation of plant
soundproofing, provision of alternative plant, erection of sound barriers
around part of the Site or the location of construction noise sources, or any
other measures that may be effective in reducing noise. Where such remedial measures include the use
of additional or alternative Constructional Plant or equipment, such
Constructional Plant or equipment shall not be used on the Works until the ER’s
consent has been given. Where remedial measures include maintenance or
modification of previously approved Constructional Plant or equipment such
Constructional Plant or equipment shall not be used on the Works until such
maintenance or modification is completed and the adequacy of the maintenance or
modification is demonstrated to the satisfaction of the ER.
3.8.9
If the above
measures are not sufficient to restore the construction noise quality to an
acceptable level upon the advice of ETL, the Contractor shall liaise with the
ETL on alternative mitigation measures, propose to ER for Approval, and carry
out the mitigation measures.
Table
3.3 Noise Monitoring Field Record
Sheet
Monitoring
Location
|
Description
of Location
|
Date of Monitoring
|
Measurement
Start Time (hh:mm)
|
Measurement
Time Length (min.)
|
Noise Meter
Model/Identification
|
Calibrator
Model/Identification
|
|
L90 (dB(A))
|
Measurement
Results
|
L10 (dB(A))
|
|
Leq (dB(A))
|
Major Construction Noise Source(s) During Monitoring
|
Other Noise Source(s) During Monitoring
|
Remarks
|
|
|
Name & Designation
|
|
Signature
|
|
Date
|
Recorded By
|
:
|
|
|
|
|
|
Checked by
|
:
|
|
|
|
|
|
4.
Water Quality
4.1.1
Surplus water may
arise on site from three main sources.
During the demolition works when it rains site run-off and surface water
drainage have the potential to contain elevated levels of suspended
solids. During the soil remediation
phase site run-off and surface water drainage will remain as a potential impact
but it may also be the case that soil decontamination procedures (including
dewatering) result in the generation of surplus water for disposal. Sewage effluents generated from the workforce
may also occur in both phases.
4.1.2
Site run-off and
drainage should be prevented or minimised in accordance with the guidelines
stipulated in the EPD Practice Note for Professional Persons, Construction Site
Drainage (ProPECC PN 1/94). Reuse of water on site is to be encouraged
wherever possible. Good housekeeping and
storm-water best management practices, detailed below, shall be implemented to
ensure that WPCO standards are met and that no unacceptable impacts on the WSR
arise due to the demolition of KTCDA.
All discharges from the site shall be controlled in order to comply with
the standards for effluents discharged into the Victoria Harbour WCZ under the
TM.
4.2.1
Sewage discharges
from the demolition workforce on site shall be connected to the existing sewer
and diverted to sewage treatment facilities.
If it emerges that that no sewer connection is available during certain stages
of the demolition works the installation of adequate portable chemical toilets
will need to be provided by a licensed contractor who will be responsible for
the proper maintenance of these facilities.
Assuming that either the foul sewer or portable toilets are utilised
throughout the demolition works no adverse water quality impacts should arise
from the demolition workforce sewage.
4.3.1
Whereas the majority
of the site has a hard concrete covering the area of potentially exposed soil
will be minimal. Such areas and the
accumulation of dust and fine waste material shall be kept to a minimum to
reduce the potential for siltation, contamination of
run-off, and erosion.
Mitigation Measures
4.3.2
Run-off related
impacts associated with demolition work and other general activities can all be
readily controlled through the use of appropriate mitigation measures which
include:
·
The use of
sediment traps, where appropriate; and
·
The adequate
maintenance of drainage systems to prevent flooding and overflow.
4.3.3
Critical areas
within the Site shall be clearly marked and provided with protective measures
to control site run-off. Temporary
channels shall be provided to facilitate run-off discharge into the appropriate
watercourses, via a silt retention pond.
Permanent drainage channels shall incorporate sediment basins or traps
and baffles to enhance deposition rates.
4.3.4
Temporary and
permanent drainage pipes and culverts which are provided to facilitate run-off
discharge shall be adequately designed for the controlled release of storm
flows. All sediment traps shall be
regularly cleaned and maintained.
Temporarily diverted drainage shall be reinstated to its original
condition when the demolition work has finished or the temporary diversion is
no longer required.
4.3.5
Wheel washing
facilities will be installed to ensure no earth, mud and debris is deposited on
roads. Sand and silt in the wash water
from such facilities shall be settled out and removed before (in line with
effluent discharge standards, Appendix C) discharging the used water into storm
drains. A section of the road between
the wheel washing bay and the public road shall be paved with backfall to prevent wash water or other site run-off from
entering public road drains.
4.3.6
Oil interception
facilities should be provided in appropriate areas in the drainage system,
where oil spills may occur, and regularly emptied to prevent the release of oil
and grease into the storm water drainage system after accidental spillage.
4.3.7
Provided the
surface run-off and drainage are effectively managed and controlled over the
site, adverse water quality impacts can be avoided.
4.3.8
All demolition
works will be land based and the EIA concludes that no insurmountable water
quality impacts will result from the demolition work of KTCDA provided that:
·
All the
recommended mitigation measures including appropriate drainage and silty run-off collection facilities are incorporated in
accordance with the recommendations of ProPEC PN
1/94;
·
All demolition
workforce sewage is discharged either to foul sewer or to temporary portable
toilets, as appropriate according to the demolition programme and methodology;
·
All temporary
drainage diversions will be reinstated to the original condition after the
demolition works are completed and implemented properly, in accordance with the
recommendations of ProPECC PN 1/94; and
·
All demolition
works area discharges must comply with the TM standards of the WPCO in respect
of all applicable WQ parameters. Any
practical options for the diversion and re-alignment of drainage should comply
with both engineering and environmental requirements. General Demolition
Activities
4.3.9
Debris and
rubbish on site should be collected, handled and disposed of properly to
prevent such material from entering the water column and causing water quality
impacts. The solid waste management
requirements are presented later in this report.
4.3.10
If required, fuel
storage areas should be provided with locks and be sited on sealed areas,
within bunds of a capacity equal to 110% of the storage capacity of the largest
container (to provide a safety margin) and control spilt fuel oils.
4.3.11
The effects on
water quality from these demolition activities are likely to be minimal
provided that site boundaries are well maintained and good site practice is
observed to ensure that litter and fuels are managed, stored and handled
properly
4.3.12
It is considered
that controls on discharges from land based demolition activities and proper
site management procedures, as referenced above, will minimise residual water
quality impacts to the acceptable levels stipulated in the WPCO criteria.
Site Run -
off
4.4.1
The above
mitigation shall also apply generally to all excavated and/or stockpiled
materials during the soil remediation process.
In practice the consultants experience suggests that runoff from the
site can be controlled even though the hard concrete covering is removed in
places and the area of potentially exposed soil in greater than during the
demolition. Surplus water arising from
dewatering is to be collected on site for re-use where possible (see below).
4.4.2
The exposed areas
and the accumulation of dust and fine waste material shall be kept to a minimum
to reduce the potential for siltation, contamination
of run-off, and erosion. It is
recommended that the mixing of concrete with contaminated soil be carried out
on an area with cover and concrete paved floor with bunding
to control run-off, especially if heavy rain were to occur during the period
while the cement sets. Bunding or sand-bagging around the excavated pits is also
recommended to minimise ingress of water.
However, impacts associated with this work
and other general activities can be all readily controlled through the use of
appropriate mitigation measures mentioned above.
Dewatering
4.4.3
In addition, the
Contractor is strongly advised to operate any necessary ground remediation
works such that discharge of groundwater should be kept to minimum. This could be achieved by:
·
minimising the
ingress of surface water, which would mix with groundwater extracted during
ground excavation if any; and
·
reusing water on-site in ground
remediation processes (mixing with cement).
4.4.5
Surplus water
arising from dewatering is to be collected on site for re-use where
possible. Groundwater and leachate shall be reused and mixed with cement in the
immobilisation process for contaminated soils.
Surplus groundwater shall be collected and tested for metals and other
pollutants for compliance with standards for effluents discharged into the
Victoria Harbour WCZ under the TM and other parameters to be agreed with EPD
prior to any consent being given to discharge.
If the concentrations of contaminants exceed the standards the surplus
water shall be treated.
Treatment
of Surplus Groundwater Prior to Discharge
4.4.6
Treatment methods
for any surplus contaminated groundwater, such as the addition of chemicals
have been covered in the EIA. These
industry standard methods will precipitate out contaminants and floating free
products can be removed using an interceptor tank by flotation. The contractor shall therefore make
provisions to include for treatment of surplus groundwater to reduce chemical
concentrations in order to comply with the standards for effluents discharged
into the inshore waters of Victoria Harbour WCZ under the TM.
4.4.7
The EIA has
indicated that it is not possible to rule out the requirement to discharge leachate. If the
volumes are low it is possible that limited quantities could be discharged to
the foul sewer. In this case the
necessary permissions and discharge licences would need to be obtained from the
authorities under the relevant legislation.
However the contractor shall not discharge directly or indirectly into
any public sewer stormwater drain any effluent or
contaminated water without the prior written consent of the site engineer in
consultation with the Director of Environmental Protection (DEP). In granting this permission the DEP may
require the contractor to maintain suitable works for the treatment and
disposal of such effluent or contaminated water (surplus groundwater or leachate). The
contractor shall therefore make provisions to include for treatment of surplus
groundwater or leachate to reduce chemical
concentrations in order to comply with the standards for effluents discharged
into the inshore waters of Victoria Harbour WCZ. These facilities should be in place before
the need arises to make any discharge of such effluent.
4.5.1
The EIA report
has recommended water quality control and mitigation measures. The Contractor shall be responsible for the
design and implementation of these measures.
Monitoring of effluents for compliance with the Marine Water Quality
will not be necessary and no insurmountable water quality impacts will result
from the demolition work of KTCDA provided that the above mitigation measures
are implemented.
5.1.1
The Contractor
shall be responsible for waste control within the construction site, removal of
the waste material produced from the site and implementation of any mitigation
measures to minimise waste or redress problems arising from the waste from the
site. The waste material will include
5.1.2
The variety of
wastes generated from demolition activities can be divided into certain
categories based on the constituent elements and include:
·
Construction and
Demolition (C&D) materials;;
·
Chemical waste;
and
·
General refuse.
5.1.3
The environmental
impacts from the various waste types are summarised in Table 5.1.
Table
5.1 Summary of Waste Management
Impacts
Waste Type
|
General
Evaluation
|
C&D material
|
The
total quantities of C&D materials which will be generated will be about
250te day-1, in
comparison with the disposal capacity available at public filling areas, it
is small. Due to the inert nature of most C&D material and the
availability of public filling areas, disposal is not likely to raise long
term environmental concerns.
|
Chemical Waste
|
A
small volume of chemical waste, as well as asbestos containing roofing
materials and weather cladding (estimate., up to
8,000m2) will be
produced. Temporary storage on site,
handling, transport and disposal must be in accordance with the Code of Practice
on the Handling, Transportation and disposal of Asbestos Waste. Provided that
this occurs, and chemical wastes are disposed of at a licensed facility, and
there will be little environmental impact.
|
General Refuse
|
If
good practice is adhered to and all feasible avoidance, reuse and recycling
opportunities are taken, including minimising over ordering, there should be
minimal impact.
|
Introduction
5.2.1
This section sets
out recycling, storage, transportation and disposal measures which are
recommended to avoid or minimise potential adverse impacts associated with
waste arisings from the demolition of the KTCDA,
under the headings of each waste type. The Contractor should incorporate these
recommendations into a comprehensive on-site waste management plan. Such a
waste management plan should incorporate site specific factors, such as the
designation of areas for the segregation and temporary storage of reusable and
recyclable materials.
Waste Management Hierarchy
5.2.2
The various waste
management options can be categorised in terms of preference from an
environmental viewpoint. The options considered to be more preferable have the
least impacts and are more sustainable in a long term context. Hence, the
hierarchy is as follows:
·
Avoidance and
minimisation by not generating waste through changing or improving practices
and design;
·
Reusing materials
and therefore avoiding disposal (generally with only limited reprocessing);
·
Recovery and
recycling, avoiding disposal (although reprocessing may be required); and
·
treatment and disposal, according to
relevant laws, guidelines and good practice.
5.2.3
The Waste
Disposal Authority should be consulted by the Contractor on the final disposal
of wastes.
5.2.4
This hierarchy
should be used to evaluate waste management options, thus allowing maximum
waste reduction and often reducing costs. For example, by reducing or
eliminating over-ordering of materials required to undertake the demolition,
waste is avoided and costs are reduced both in terms of purchasing and in
disposing of wastes.
C&D material
5.2.5
At this stage a
broad estimate up to 2500m3 of C&D materials will arise at the
KTCDA demolition site each month, however this may change subject to the
Contractor’s programme. Generation of
C&D waste requiring disposal at landfill(s) is estimated to be a relatively
low proportion of this total. In order to minimise waste and maintain
environmental impacts within acceptable levels, the mitigation measures
described below should be adopted. It can also be expected that some small
quantities of oil stained concrete will be generated and these will need to be
treated as chemical waste for disposal purposes and appropriate measures are
described.
5.2.6
In accordance
with the New Disposal Arrangement for Construction Waste, Environmental
Protection Department, 1992, disposal of C&D material can either be at a
specified landfill, or as public fill with the latter being the preferred
option. However C&D materials currently comprise a high proportion of
C&D waste inputs to landfills and in order to maximise landfill life,
Government policy prohibits the disposal of C&D material to landfill if it
contains more than 20% inert material by volume. Such inert wastes are directed
to reclamation areas, where they have the added benefit of offsetting the need
for removal of materials from terrestrial borrow areas for reclamation
purposes. In the same way that materials which may be recycled should be
segregated from other wastes, clean inert waste, suitable for disposal at
public filling areas, should be segregated from any ‘contaminated’ wastes which
will require landfill disposal.
5.2.7
The Contractor
should recycle C&D material on-site as far as possible. Planning, careful
design and good site management of the demolition process can minimise over
ordering and avoidable waste. Areas within the Site areas can be segregated for
the separation and storage. Proper segregation of wastes on site will increase
the feasibility of utilising recycling Contractors to recycle certain
components of the waste stream. Concrete and masonry can be crushed and used as
fill to level the site after demolition. However there will be little or no
excavation of any underground structures therefore the majority of inert waste
will need to be delivered to public filling areas. Steel reinforcing bars can
be re-used by scrap steel mills.
5.2.8
If landfill
disposal has to be used, the C&D wastes will most likely be delivered to
the WENT Landfill or SENT Landfill. Government is currently studying the
possibilities of introducing a pilot C&D waste recycling facility that
would offer another alternative if it were in operation by the time demolition
for KTCDA takes place.
5.2.9
The provisions of
WBTC No. 5/98 (On Site Sorting of Construction Waste on Demolition Sites) shall
be followed. At present, Government is
developing a charging policy for the disposal of C&D waste to landfill.
When it is implemented, this will provided additional incentive to reduce the
volume of waste generated and hence encourage the appropriate sorting and
segregation of different types of C&D material.
Chemical Waste
5.2.10 For those processes that generate chemical waste, it may be possible
to find alternatives which generate reduced quantities or even no chemical
waste, or less dangerous types of chemical waste.
5.2.11 Chemical waste that is produced, as defined under section 3 of the
Waste Disposal (Chemical Waste) (General) Regulation, should be handled in
accordance with the Code of Practice on the Packaging, Labelling and Storage of
Chemical Wastes as follows.
5.2.12 Containers used for the storage of chemical wastes should:
·
Be suitable for
the substance they are holding, resistant to corrosion, maintained in a good
condition, and securely closed;
·
Have a capacity
of less than 450l unless the specifications have been approved by the EPD; and
·
Display a label
in English and Chinese in accordance with instructions prescribed in Schedule 2
of the Regulations.
5.2.13 The storage area for chemical wastes should:
·
Be clearly
labelled and used solely for the storage of chemical waste;
·
Be enclosed on at
least 3 sides;
·
Have an
impermeable floor and bunding, of capacity to
accommodate 110% of the volume of the largest container or 20% by volume of the
chemical waste stored in that area, whichever is the greatest;
·
Have adequate
ventilation;
·
Be covered to
prevent rainfall entering (water collected within the bund must be tested and
disposed as chemical waste if necessary); and
·
Be arranged so
that incompatible materials are adequately separated.
5.2.14 Disposal of chemical waste should:
·
Be via a licensed
waste collector; and
·
Be to a facility
licensed to receive chemical waste, such as the Chemical Waste Treatment
Facility which also offers a chemical waste collection service and can supply
the necessary storage containers; or
·
Be to a recycling
or reprocessing facility licensed by EPD.
5.2.15 The Centre for Environmental Technology operates a Waste Exchange
Scheme which can assist in finding receivers or buyers.
5.2.16 Asbestos waste that is produced should be handled in accordance with
the Code of Practice on the Handling, Transportation and Disposal of Asbestos
Wastes. The detailed requirements will be presented in the Asbestos Study
Report.
Disposal of Residual Rubble / Ash Waste (Between
KTIP Chimneys)
5.2.17 EPD indicated that the PCDD/PCDF contaminated rubble / ash waste
(300m3 approx.) could be disposed of at CWTC. Remedial action has been recommended and
action will be required to clean up these materials prior to the
demolition. Treatment on-site prior to
disposal at a landfill is the preferred method.
This material must be immobilised on site,
tested to ensure compliance with TCLP testing requirements (Appendix D) and
removed by an appropriately qualified specialist contractor and must be
collected, deposited at landfill in accordance with criteria and conditions as
specified in agreement with EPD.
5.2.18 The proposed method of disposal is for the ash waste to be collected
up and stabilised to meet landfill disposal criteria of EPD. In this case it is envisaged that the process
would involve collection and mixing the ash material
with cement. Pilot mixing and TCLP tests
should establish the ratio of cement to ash to the satisfaction of EPD. The materials for disposal would then be
treated and the extracted material placed into polythene lined steel
drums. Transparent plastic sheeting of
0.15mm thickness low-density polythene or PVC should be employed. The drums should be 16 gauge
steel or thicker and fitted with double bung fixed ends adequately sealed and
well labelled in new or good condition.
Prior agreement of the disposal criteria from EPD and agreement to
disposal from the landfill operator must be obtained.
5.2.19 The SENT Landfill has been identified as the appropriate location
for disposal. However, disposal at the
CWTC should be considered as a fall back option (as a last resort) if the
landfill disposal criteria cannot be met.
Protection of Site Workers
5.2.20 The release of contaminants from disturbed ash should be minimised
prior to gathering up the ash materials and amended water containing a wetting
agent should be sprayed on the ash. The
wetting agent will assist in water penetration to thoroughly soak the ash and
ensure dust levels are reduced without use of excessive water. (Spray shall comprise 50% polyoxyethylene
ester and 50% polyoxyethylene ether, or equivalent,
diluted to specific concentration in accordance with the manufacturer’s
instructions). The use of amended water
for dust suppression will minimise the use of excessive water that would result
in surface runoff in the removal process.
Dust suppression can therefore be carried out in a controlled manner and
no insurmountable environmental problem would result.
5.2.21 Given the nature of the work and the contaminants involved consideration
should be given to the use of decontamination facilities (showers) that should
be provided for the work force to remove contamination after work.
5.2.22 Preliminary provisions for the protection of workers during the
management of the ash removal are presented in Appendix E.
5.2.23 Handling, transportation and disposal of the ash waste shall be
carried out according to the relevant regulations.
5.2.24 As a fall back option the materials can be transported to the CWTC
for disposal if the landfill criteria cannot be met. No PCDD/PCDF were
detected above the USEPA criterion at any other locations in soil samples. Remedial action will be required to clean up
these materials prior to the demolition.
The material that is contaminated is deposited on the walls. As such, there is no opportunity for in-situ
containment or treatment of this material in the context of the ultimate
redevelopment of the site. Therefore,
there is no alternative but to dispose of this material offsite. This should be undertaken prior to the demolition
of any structures.
General Refuse
5.2.25 General refuse should be stored in enclosed bins or compaction units
separate from demolition and chemical wastes. A reputable waste collector
should be employed by the Contractor to remove general refuse, separately from
C&D material and chemical wastes, daily to minimise odour, pest and litter
impacts. The burning of refuse on construction sites is prohibited by law.
5.2.26 General refuse is generated largely by food service activities on
site, so reusable rather than disposable dishware should be used if feasible.
Aluminium cans are often recovered from the waste stream by individual
collectors if they are segregated or easily accessible, so separate, labelled
bins for their deposit should be provided if feasible.
5.2.27 Office wastes can be reduced through recycling of paper if volumes
are large enough to warrant collection. Participation in a local collection
scheme should be considered if one is available.
Storage areas for different waste types
5.2.28 Different types of waste should be segregated and stored in
different containers, skips or stockpiles to enhance reuse or recycling of
materials and their proper disposal.
5.2.29 An on-site temporary storage area should also be provided.
5.2.30
In order to
monitor the disposal of C&D and solid wastes at public filling facilities
and landfills, and control fly-tipping, a trip-ticket system (Works Bureau
Technical Circular No. 5/99, Trip-ticket System for Disposal of Construction
and Demolition Material) should be included as one of the contractual
requirements and implemented under the supervision of the Environmental
Team. The system should be subject to
independent auditing by the IC(E).
Training and Records of wastes
5.2.31
A waste
management plan will be requited under Works Bureau Technical Circular No.
29/2000. This should include a
description of the training proposed to educate the workforce on the
requirements of the Waste Disposal Ordinance, subsidiary legislation and
guidelines listed above. The training
should include, as a minimum, arrangements for waste management, On Site
Sorting of Construction Waste on Demolition Sites (WBTC No. 5/98), Trip-ticket
System for Disposal of Construction and Demolition Material (WBTC No. 5/99).
5.2.32
A recording
system for the amount of wastes generated, recycled and disposed (including the
disposal sites) should be proposed.
5.3.1
This section
describes waste management requirements and provides practical actions which
can be taken to minimise the impacts arising as a result of the generation,
storage, handling, transport and disposal of wastes. A Waste Management Plan will be required for
all stages of the demolition and soil remediation works in line with Works
Bureau Technical Circular No. 29/2000.
5.3.2
Waste reduction
is best achieved at the planning and design stage, as well as by ensuring that
processes are run in the most efficient way.
Good management and control can prevent the generation of significant
amounts of waste. For unavoidable wastes, reuse, recycling and optimal disposal
are most practical when segregation occurs on the demolition site, as follows:
·
Public fill
(inert) for disposal at public filling areas;
·
C&D waste
(non-inert) for landfill;
·
Chemical waste
for treatment at licensed facilities; and
·
General refuse
for disposal at landfill.
5.3.3
The criteria for
sorting solid waste is described in New Disposal Arrangements for Construction
Waste, Environmental Protection Department and Civil Engineering Department,
1992 and Works Bureau Technical Circular No. 5/98, On Site Sorting of
Construction Waste on Demolition Sites. C&D material containing in excess
of 20% by volume of inert materials should be segregated from C&D waste
with a larger proportion of putrescible
material. In preference the inert
materials shall be directed to the proposed Pilot C&D Waste Recycling
Facility at Kai Tak and after early 2005 excess
materials could be directed to the adjacent proposed public filling barging
point on Area 30D.
5.3.4
Proper storage
and site practices will minimise the damage to, or contamination of, demolition
C&D materials that may reduce their recyclability
and suitability for disposal in public filling areas. On site measures may be implemented which
promote the proper disposal of wastes once off-site. For example having separate
skips for inert (rubble, sand, stone, etc) and non-inert (wood, organics, etc)
materials would help to ensure that the former are taken to public filling
areas, while the latter are properly disposed of at controlled landfills. Since
public fill brought to public filling areas will not attract a charge, while
C&D waste taken to landfill may attract some charge in the future,
separating C&D material may also help to reduce waste disposal costs,
should landfill charging be introduced.
5.3.5
Specifically, it
is recommended that:
·
Wastes should be
handled and stored in a manner which ensures that they are held securely
without loss or leakage thereby minimising the potential for pollution;
·
Only reputable
waste collectors authorised to collect the specific category of waste concerned
should be employed;
·
Appropriate
measures should be employed to minimise windblown litter and dust during
transportation by either covering trucks or transporting wastes in enclosed containers;
·
The necessary
waste disposal permits should be obtained from the appropriate authorities, if
they are required, in accordance with the Waste Disposal Ordinance (Cap 354),
Waste Disposal (Chemical Waste) (General) Regulation and the Government Land
Ordinance (Cap 28);
·
Collection of
general refuse should be carried out frequently, preferably daily;
·
Waste should only
be disposed of at licensed sites and site staff and the civil engineering
Contractor should develop procedures to ensure that illegal disposal of wastes
does not occur;
·
Waste storage
areas should be well maintained and cleaned regularly; and
·
Records should be
maintained of the quantities of wastes generated, recycled and disposed,
determined by weighing each load.
EM&A Requirements
5.3.6
It is recommended
that auditing of each waste stream, including any waste arising from the
decontamination of soils and the remediation procedures should be carried out
periodically by the EM&A Team to determine if wastes are being managed in
accordance with approved procedures. The
audits should look at all aspects of waste management including waste
generation, storage, recycling, treatment, transport, and disposal. An appropriate audit programme would be to
undertake a first audit at the commencement of the demolition works, and then
to audit quarterly thereafter.
5.3.7
It is likely that
relatively small quantities of C&D materials will require disposal at
landfill. The bulk of the C&D materials will be disposed at public filling
areas and some, in particular reinforcement bar, will be recycled. Limited quantities of chemical wastes (mainly
asbestos) and general wastes will be generated. Mitigation measures relating to
good practice have been recommended to ensure that adverse environmental
impacts are prevented and that opportunities for waste minimisation and
recycling are followed.
5.3.8
Provided that the
recommendations are thoroughly implemented the storage, handling, collection,
transport, and disposal of wastes arising from the demolition of KTCDA will be
in full compliance with the regulatory requirements.
6.1.1
During the
demolition phase, the monitoring and audit requirements recommended include a
proactive approach to air quality and noise monitoring. The demolition will only be for above ground
structures but the approach should continue throughout the soil remediation
phase.
6.1.2
During the
subsequent soil remediation, requirements for clean-up and procedures are in
line with the Guidance Notes for Investigation and Remediation of Contaminated
Site documented in the EIA Report.
Actions required post demolition are presented in Table 6.1, which
indicates where remedial action will be required, where reassurance/confirmatory
sampling is warranted and summarises the locations requiring clean up based on
the available information. In order to
make sure that all contaminated material is excavated a margin of about
0.5metre is allowed above and below the shallowest and deepest contamination
detected. In addition reassurance /
confirmatory sampling is required at the boundaries of
the excavations to make sure that all contaminated material is excavated. If residual contamination is still detected
by the reassurance sampling at the periphery of the excavation, the pit shall
be extended one metre in the direction of the residual contamination. The extracted soil shall be treated as with
the materials already extracted in that location and reassurance / confirmatory
sampling carried out again.
6.1.3
The ETL will be
required to audit the working methods to ensure that the remediation is carried
out according to the specification and the recommendations of the EIA. The above recommendations for air, waste and
water quality monitoring will apply.
Reassurance sampling will be required to ascertain that the remedial
action plan has been carried out effectively and a summary report shall be
issued to EPD at the completion of the remedial works programme. Interim reports should also be submitted to
allow EPD to monitor the progress of the remedial works.
Management
of Contaminated Soil Material
6.2.1
Although ground
conditions on the site are contaminated with metals and some organic compounds,
at this stage the only opportunity for human exposure to any of the contamination
on site will be if the materials are excavated.
Contaminated rubble / ash waste (300m3 approx.) will be cleaned up prior to the demolition and treatment
on-site prior to disposal at a landfill is the preferred method. This material must be treated on site (see
section 5) and removed by an appropriately qualified specialist contractor and
must be collected, deposited at landfill in accordance with criteria and
conditions as specified in agreement with EPD.
6.2.2
For this site and
any potential redevelopment, the preferred approach with least environmental
impact, is to cause minimal disturbance to the ground conditions, immobilise
the contaminated soils where necessary and make provisions for the protection
of workers. Where this is not
appropriate the disposal of some small amount of material to landfill may be a
more suitable remedial option.
Volume of Soil for Immobilisation
6.2.3
The volume of
soil to be treated on site has been estimated by making a broad brush estimate
based on depths to which materials >Dutch B are
identified by sampling. The estimated
total of about 6055m3 is preliminary and assumes that all material
within 5m (10m x 10m square hole) at the contaminated depths would be
treated. This includes the 1420m3 for
disposal at landfill. The material is
not disposed of off site and therefore off site effects are minimised. However it is possible that reassurance
sampling at the periphery and base of the excavations will identify further
contaminated materials at a later stage, however it is not possible to predict
the extent of this contamination based on current information.
Volume of Soil to Landfill
6.2.4
A volume of about
1220m3 contaminated with hydrocarbons would be directed to
landfill. Again this estimate is
preliminary and assumes that all material within 5m (10m x 10m square hole) at
the contaminated depths would be treated.
In this case the material is disposed off-site, however the quantities
are small perhaps resulting in a few tens of lorry loads and therefore off-site
effects are not expected to cause any in-surmountable environmental
problems. The precise volume of
hydrocarbon contaminated waste is also difficult to determine. However, the hydrocarbon contaminated soil
appears to be confined to the lower depths at one end of the site. Whereas it is possible that reassurance
sampling at the periphery and base of the excavations will identify further
contaminated materials at a later stage, it is not possible to predict the
extent of any additional contamination based on current information.
6.3.1
General site
safety provisions incorporate some basic practices such as the provision of
safety boots, hard hat, overalls, gloves and eye protection. In addition, dust masks shall be made
available and sufficient first aid facilities and procedures and appropriate
washing amenities. It is important to
avoid skin contact, ingestion and inhalation of contaminated materials, however
this would not normally be a significant risk provided basic personal
protective equipment is provided. In
addition to statutory occupational safety requirements site staff shall be
given adequate training and instruction specific to the potential hazards in
the work place, their health and safety responsibilities and safe working
practice including basic personal hygiene, which is important on contaminated
sites.
6.3.2
Given the
potential for hydrocarbons (TPH) in the soil and groundwater, skin contact
shall be avoided. Prolonged exposure
(i.e. skin contact) can potentially result in dry skin, irritation and allergic
dermatitis although these effects would not normally cause acute reactions at
the concentrations encountered so far encountered at this site. Exposure to dusty material shall be
avoided. Dust shall be controlled at
source by damping techniques and operatives shall be protected by the use of
dust masks.
6.3.3
To ensure that
the health and safety measures outlined above are actually implemented on-site,
specific clauses can be incorporated into the contract documents, and the
proponent shall provide and EM&A team with experienced staff on similar
sites in Hong Kong to supervise/audit the demolition. This supervision will ensure that the
specific contractual clauses are followed and that health and safety on the
site is given a high priority.
Table
6.1 Actions
Required Post Demolition
Borehole
|
Action
Required
|
Remove
concrete surface and clear uncontaminated surface material and stockpile
|
Proposed
depth of Material for Removal or Treatment
|
Remedial
Action
|
Estimate
quantity of contaminated material for Treatment
(m3, #)
|
Reassurance
/ Confirmatory Sampling
|
Sampling
Strategy
|
TB1
|
Yes
|
Concrete down to
0.3m depth
|
Immediately
below concrete 0.3m to 4.0m
|
Immobilisation
for 0.3m to 2.0m and 3.0m to 4.0m*
TCLP test
followed by removal of 2.0m to 3.0m to landfill. Immobilisation if TCLP tests exceed
criteria **.
|
100 to be removed to landfill
+
270 @
|
Yes, determine
extent of HM (Cd, Cu, Pb,
Zn and Hg) and TPH contamination at edge and base of excavated hole.*
|
5 samples 5m N,
S, E ,W and base of borehole.
|
TB2
|
Yes
|
Concrete down to
0.5m depth
|
Immediately
below concrete 0.5m to 1.5m
|
Immobilisation*
|
100
|
Yes, determine
extent of HM (As, Cu, Pb and Zn) contamination at
edge and base of excavated hole.*
|
5 samples 5m N,
S, E ,W and base of borehole.
|
TB3
|
Yes
|
Concrete down to
2.5m depth
|
2.5m to 3.5m
|
Immobilisation *
|
100
|
Yes, determine
extent of HM (Cu, Pb, Zn and Hg) contamination at
edge and base of excavated hole.*
|
5 samples 5m N,
S, E & W and base of borehole.
|
TB4
|
Yes
|
Down to 2.2m
depth
|
2.2m to 4.2m
|
Immobilisation *
|
200
|
Yes, determine
extent of HM (As, Cu, Pb and Zn) contamination at
edge and base of excavated hole.*
|
4 samples 5 m N,
S, E & W of borehole plus one at base of hole layer
|
TB5
|
Yes
|
Concrete down to
1.8m. Down to 2.5m depth
|
2.5m to 4.0m
|
Immobilisation*
|
200
|
Yes, determine
extent of HM (Pb) contamination at edge and base of
excavated hole.*
|
4 samples 5 m N,
S, E & W of borehole plus one at base of hole layer
|
TB6
|
No
|
N/A
|
N/A
|
N/A
|
0
|
N/A
|
N/A
|
TB7
|
No
|
N/A
|
N/A
|
N/A
|
0
|
N/A
|
N/A
|
TB8
|
Yes
|
Concrete down to 1m. Down to 2.5m
|
2.5m to 3.5m
|
TCLP test followed by removal of 2.5m to 3.5m to
landfill. Immobilisation if TCLP tests
exceed criteria **.
|
100 to be removed to landfill @
|
Yes, determine
extent of PAH contamination at edge and base of excavated hole.*
|
5 samples 5m N,
S, E ,W and base of borehole.
|
TB9
|
Yes
|
Concrete down to
1.0m depth
|
1.0m to 2.0m
|
Immobilisation*
|
100
|
Yes, determine
extent of HM (Pb) contamination at edge and base of
excavated hole.*
|
4 samples 5m N,
S, E & W and base of borehole.
|
TB10
|
Yes
|
Surface
rubble/ash and brick material (not soil) about 1.5m depth.
|
1.5 m
|
Clear Waste to landfill. Waste to be treated and tested to meet EPD
disposal criteria.
|
Up to, say, 300m3 (surface material, not for
in-situ treatment) @
|
Yes, determine
extent of HM (As, Cd, Cu, Pb,
Zn) TPH and PCDD/PCDF contamination under surface contaminated materials.*
|
|