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

 

 

 

 

 

 

Environmental Impact Assessment (Final Report)

 

 

 

 

September 2001

 

 

 

 

 

 

 

 

 

 

Atkins China Ltd


 

Client :                Civil Engineering Department

 

Contract No. (if any) : -

CE 15/99

 

 

Project Title :       Environmental Impact Assessment for Demolition of Kwai Chung Incinerator Plant and Kennedy Town CDA

 

 

Project No. :  2996

 

 

Document No. :    2996-OR025-05

 

 

 

Controlled Copy No. :

 

           

 

Document Title :  Final Environmental Impact Assessment
                           Kennedy Town CDA

 

 

 

Covering Letter / Transmittal Ref. No. :

                           2996/15.40/

 

 

Date of Issue :

    September 2001

 

Revision, Review and Approval/Authorisation Records

05

6th Issue

Various/

JWS/

DG/

04

5th Issue

Various/

JWS/

DG/

03

4th Issue

Various/

JWS/

DG/

02

3rd Issue

Various/

JWS/

 

DG/

 

01

2nd Issue

Various/

WD/

DG/

00

1st Issue

Various/

JWS/

WD/

Revision

Description

Prepared by / date

Reviewed by / date

App. or Auth. By / date

 

Distribution (if insufficient space, please use separate paper)

Controlled Copy No.

Issued to

 

1-45

Civil Engineering Department

46-47

ACL – ELAN

 

 

 

Note : App. and Auth. mean “Approved” and “Authorised” respectively.


Table of Contents

Executive Summary

1.      Introduction. 1-1

1.1        Background to the Study. 1-1

1.2        Purpose and Objectives of the Assignment 1-2

1.3        Structure of the Report 1-3

2.      Study Area, Sensitive Receivers, Constraints and General Approach to Demolition. 2-1

2.1        Study Area KTCDA.. 2-1

2.2        Sensitive Receivers. 2-2

2.3        Options for Demolition. 2-4

2.4        General Approach to Demolition of Buildings and Structures at KTCDA.. 2-7

2.5        Principles of Chimney Demolition at KTCDA.. 2-8

3.      Asbestos Control 3-1

3.1        Site Location and Description. 3-1

3.2        Asbestos Investigation Methodology. 3-2

3.3        ACM to be Removed. 3-3

3.4        Justification of Methods. 3-6

3.5        General Safety Measures. 3-8

3.6        Programme for Asbestos Removal 3-8

3.7        Regulations, Codes of Practice and Local Requirements. 3-9

4.      Land Contamination. 4-1

4.1        Requirement for Land Contamination Assessment 4-1

4.2        Land Use History. 4-1

4.3        Site Inspection. 4-2

4.4        Methodology. 4-4

4.5        Sampling Locations and Analysis of Results. 4-6

4.6        Contamination Assessment 4-14

4.7        Remediation Action Plan. 4-17

4.8        Procedures for Management of Contaminated Rubble / Ash Waste  Material 4-23

4.9        Management of Contaminated Soil Material 4-26

4.10      Protection of Site Workers During Excavation and Treatment of Soils. 4-29

5.      Noise. 5-1

5.1        Introduction. 5-1

5.2        Government Legislation and Standards. 5-1

5.3        Existing Noise Conditions. 5-2

5.4        Noise Sensitive Receivers. 5-2

5.5        Potential Sources of Impact 5-3

5.6        Assessment Methodology. 5-3

5.7        Evaluation of Impacts. 5-5

5.8        Mitigation Measures. 5-6

6.      Air Quality. 6-1

6.1        Introduction. 6-1

6.2        Government Legislation and Standards. 6-1

6.3        Dust Suppression Measures. 6-2

6.4        Vehicle Emissions. 6-3

6.5        Odour. 6-3

6.6        Conclusions. 6-3

7.      Waste Management 7-1

7.1        Introduction. 7-1

7.2        Assessment Criteria and Methodology. 7-1

7.3        Waste Disposal Ordinance. 7-1

7.4        Waste Disposal (Chemical Waste) (General) Regulation. 7-2

7.5        Dumping at Sea Ordinance. 7-2

7.6        Land (Miscellaneous Provisions) Ordinance. 7-2

7.7        Public Cleansing and Prevention of Nuisance Regulation. 7-2

7.8        Additional Guidelines. 7-3

7.9        Impacts of Wastes Generated from Demolition. 7-4

7.10      Mitigation Measures. 7-7

7.11      Waste Management Planning. 7-11

8.      Environmental Monitoring and Audit 8-1

8.1        Introduction. 8-1

8.2        Environmental Monitoring and Audit 8-1

8.3        Event Contingency Plans (ECPs). 8-2

8.4        Reporting. 8-2

9.      Conclusions and Recommendations. 9-1

9.1        Introduction. 9-1

9.2        Demolition Methodology. 9-1

9.3        Asbestos. 9-1

9.4        Land Contamination and Remediation. 9-2

9.5        Noise. 9-2

9.6        Air Quality. 9-2

9.7        Waste Management. 9-2

9.8        Environmental Monitoring and Audit. 9-3

 


 

List of Tables

Table 2.1      Structures to be demolished at KTCDA   2-2

Table 3.1      Main Locations for ACM Investigation at KTCDA   3-3

Table 3.2      Areas of ACM Identified by Functional Zone  3-4

Table 3.3      Estimate of Amount of ACM Weather Cladding  3-5

Table 4.1      Summary of Analytical Results – Soil Samples  4-7

Table 4.2      Summary of Analytical Results – Groundwater Samples  4-13

Table 4.3      Actions Required Post Demolition  4-20

Table 5.1      Noise Standards for Daytime Construction Work  5-2

Table 5.2      Representative Noise Sensitive Receivers  5-3

Table 5.3      Estimated Distances from Chimneys  5-3

Table 5.4      Base Suite of Demolition/Construction Plant 5-4

Table 5.5      Base Suite of Soil Remediation Construction Plant 5-5

Table 5.6      Predicted Unmitigated Noise Levels from Demolition  5-5

Table 5.8      Revised Suite of Demolition and Ground Remediation Plant 5-8

Table 5.9      Predicted Mitigated Noise Levels from Demolition of Buildings other than Chimneys  5-9

Table 5.10     Predicted Mitigated Noise Levels from Demolition of Chimneys Only  5-9

Table 5.11     Predicted Mitigated Noise Levels (Ground Remediation) 5-10

Table 6.1      Representative Air Sensitive Receivers  6-1

Table 6.2      Hong Kong Air Quality Objectives (mg/m3) (a) 6-2

Table 7.1      KTCDA Principal Demolition Products  7-5

Table 7.2      Summary of Waste Management Impacts  7-7

Table 8.1      Schedule of Impacts and Mitigation Measures  8-3

 

List of Figures

Figure 1.1         Kennedy Town CDA Locality Plan

Figure 2.1         Kennedy Town CDA Sensitive Receivers & Constraints

Figure 2.2         Kennedy Town CDA Outline Zoning Plan

Figure 2.3         Typical Perimeter Noise Barrier

Figure 2.4         External Working Platforms KTCDA Chimneys

Figure 4.1         Kennedy Town CDA Borehole Locations

Figure 4.2         Contaminated Locations Requiring Clean Up

 

List of Appendices

Appendix A    Preferred Demolition Methodology (Extracted From WP1 Originally Presented November 1999)

Appendix B    Criteria for Soil Contamination and Landfill Disposal of Contaminated Soil

Appendix C    Water Quality Standards

Appendix D    Hazards & Safety Requirements

Appendix E     Environmental Outcome Profile

 

 


List of Abbreviations

AAP

Asbestos Abatement Plan

ACE

Advisory Council on Environment

ACM

Asbestos Containing Material

AIR

Asbestos Investigation Report

AP

Authorised Person

APCO

Air Pollution Control Ordinance

AQO

Air Quality Objective

ASR

Air Sensitive Receivers

ASTM

American Society for Testing Materials

BTEX

Benzene, Toluene, Ethylbenzene and Xylene

BOO

Building Ordinance Office

CAP

Contamination Assessment Plan

CAR

Contamination Assessment Report

CED

Civil Engineering Department

CP

Car Park

CPLD

Committee on Planning & Land Development

CSTG

Cadogan Street Temporary Garden

CSL

Registered Asbestos Consultant

DCDB

Draft Code of Practice for Demolition of Buildings

DSD

Drainage Services Department

EIA

Environmental Impact Assessment

EIAO

Environmental Impact Assessment Ordinance

EM&A

Environmental Monitoring & Audit

EMSD

Electrical & Mechanical Services Department

EPD

Environmental Protection Department

FEHD

Food and Environmental Hygiene Department

G I/C

Government, Institutional/Community

GDBL

Gin Drinker’s Bay Landfill

HEC

Hong Kong Electric

HOKLAS

Hong Kong Laboratory Accreditation Scheme

IAR

Initial Assessment Report

KTA

Kennedy Town Abattoir

KTCDA

Kennedy Town Comprehensive Development Area

KTIP

Kennedy Town Incineration Plant

MTIA

Marine Traffic Impact Assessment

NCO

Noise Control Ordinance

NSR

Noise Sensititve Receiver

NWFB

New World First Bus

PCDD / PCDF

Dioxins and Furans

PCWA

Public Cargo Working Area

PFBP

Public Fill Barging Point

PAC / PAH

Poly Aromatic Hydrocarbons

PME

Powered Mechanical Equipment

PPFS

Preliminary Project Feasibility Study

PQA

Preliminary Quantitative Assessment

RAC

Registered Asbestos Contractor

RAP

Remediation Action Plan

R7

Route 7

RCP

Refuse Collection Point

RSE

Resident Site Engineer

SB

Study Brief

SR

Sensitive Receiver

TMEIA

Technical Memorandum on the EIA Ordinance

TM

Technical Memorandum

TPH

Total Petroleum Hydrocarbons

URA

Urban Renewal Authority

WDO

Waste Disposal Ordinance

WP1

Working Paper 1


1.                  Introduction

1.1              Background to the Study

1.1.1          The Civil Engineering Department (CED) of the Government of the Hong Kong Special Administrative Region (CED) presented to EPD a project profile for the Demolition of Buildings and Structures within the Proposed Kennedy Town Comprehensive Development Area (KTCDA).  A study brief (ESB-023/98) for the EIA of the demolition was issued by EPD under the EIAO in December 1998.  CED subsequently compiled a Study Brief (SB) for the consultants and appointed Atkins China Ltd to provide professional consulting services for the Environmental Impact Assessment for the Demolition of the Kennedy Town Comprehensive Development Area (under Agreement No. CE 15/99).  The detailed technical requirements of the EIAO SB (ESB-023/98) require assessment of specific impacts associated with air quality, noise, waste management, land contamination, hazard to life, environmental monitoring and audit.  Air quality and hazard assessments are required only in the event that a blasting methodology was adopted for the demolition.  Impacts on landscape, ecology, water quality, historical and cultural heritage, land use, agriculture and fisheries are not identified to be of concern in the SB for Agreement No. CE 15/99 which includes the requirements of the study brief issued under the EIAO (ESB-024/98).

1.1.2          The demolition of a municipal incinerator constitutes a designated project under the provisions of the Environmental Impact Assessment Ordinance (EIAO).  The Kennedy Town Incineration Plant (KTIP) site has been decommissioned and requires demolition.  There is an animal carcass incinerator at Kennedy Town Abattoir (KTA) that remains temporarily in operation although this will also require decommissioning.  If the project were not to proceed, the premises will progressively dilapidate and fall into disrepair, potentially causing hazard to the surrounding environment and general public and therefore demolition is required in due course.  Public concerns can be summed up as being that the decommissioned plant is removed safely with the minimum of necessary disturbance to the daily routine of the local environs.

1.1.3          This EIA Report has been structured to present the key issues and available data in a form that reflects the topics requiring study as required under the SB.  The preferred demolition methods have been agreed and noise and waste management assessments have been completed.  Based on professional judgement air quality assessment is not required because of the nature, scale and location of the project and the elected demolition method will not include blasting techniques.  The requirements of the Air Pollution Control (Construction Dust) Regulation, under the APCO will apply, ensuring that air quality is in compliance with established standards and criteria.  Dedicated reports on land contamination and asbestos assessments have been completed after Site Investigation and the investigations and asbestos and land contamination assessments are therefore presented in summary in this EIA.

1.1.4          In order to satisfy the requirements of the EIA it is necessary to define clearly the nature of the works involved in the demolition process.  At an early stage of the study a Working Paper (WP1 on Preferred Demolition Methodology) was presented and endorsed by the First Steering Group Meeting (1st December 1999).  The development of a conceptual scheme for the demolition process reviewed in WP1 is presented at Appendix A to describe the project.  The conceptual scheme for demolition of the facilities has been developed based on practical experience and current demolition practice in Hong Kong and internationally.  Blasting will not be used in the demolition process.

1.1.5          The KTCDA is surrounded by residential development and other sensitive uses (Figure 1.1).  The risks, hidden costs and knock on effects of implementing any proposal which would include blasting techniques for the felling of the chimneys or the main building structures make such options unattractive.  Consequently a conceptual demolition method has been developed which avoids most of the complications associated with blasting and provides flexibility for the implementation stages of the works.  The conclusion is that non-blasting demolition methods should be used for the demolition of Kennedy Town Comprehensive Development Area.

1.2              Purpose and Objectives of the Assignment

1.2.1          The purpose of this study is to provide information on the nature and extent of environmental impacts, and potential safety and health hazards, arising from the demolition and clearance of all buildings, structures and chimneys, and remediation of contaminated ground, within the proposed Kennedy Town Comprehensive Development Area (KTCDA) Site (the proposed “Project”) and related activities taking place concurrently.  This information will contribute to decisions on :-

a)      the overall acceptability of any adverse environmental consequences that are likely to arise as a result of the proposed Project;

b)      the conditions and requirements for the detailed design and/or demolition of the proposed project to mitigate against adverse environmental consequences and potential safety and health hazards wherever practicable;

c)      the acceptability of residual impacts after the proposed mitigation measures are implemented.

1.2.2          The objectives of the Environmental Impact Assessment (EIA) study are as follows :

a)      to describe the proposed project and associated works together with the requirements for carrying out the proposed project;

b)      to identify and describe the elements of the community and environment likely to be affected by the proposed project and/or likely to cause adverse impacts to the proposed project, including both the natural and man-made environment;

c)      to identify and qualify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses;

d)      to propose the provision of infrastructure or mitigation measures so as to minimise pollution, environmental disturbance and nuisance during demolition;

e)      to identify, predict and evaluate the residual (i.e. after practicable mitigation) environmental impacts and the cumulative effects expected to arise during the demolition of the facilities in relation to the sensitive receivers and potential affected uses;

f)       to identify, assesses and specify methods, measures and standards, to be included in the detailed design and demolition of the project which are necessary to mitigate these environmental impacts and reducing them to acceptable levels;

g)      to investigate the extent of side-effects of proposed mitigation measures that may lead to other forms of impacts;

h)      to identify constraints associated with the mitigation measures recommended in the EIA study; and

i)        to design and specify the environmental monitoring and audit requirements, if required, to ensure the implementation and the effectiveness of the environmental protection and pollution control measures adopted.

1.3              Structure of the Report

1.3.1          A description of the elements of the community and environment, likely to be affected by the proposed demolition activities is provided in Section 2.  This is presented to confirm potential constraints on the demolition works, due to the need to protect sensitive receivers, surrounding infrastructure or facilities.  The summary establishes requirements that have been identified and which constrain the way the proposed Project is executed including the choice of demolition methods.

1.3.2          In addition to this introduction the EIA includes sections covering the following:

·               Section 2  Study Area, Sensitive Receivers, Constraints and General Approach to Demolition.

·               Section 3  Asbestos Control.

·               Section 4  Land Contamination.

·               Section 5  Noise.

·               Section 6  Air Quality.

·               Section 7  Waste Management.

·               Section 8  Environmental Monitoring and Audit.

·               Section 9  Conclusions and Recommendations.


2.                  Study Area, Sensitive Receivers, Constraints and General Approach to Demolition

2.1              Study Area KTCDA

2.1.1          The proposed Kennedy Town Comprehensive Development Area (KTCDA) is situated next to Victoria Road and Cadogan Street, Kennedy Town, and adjacent to Victoria Harbour, with a Site area of about 34,000 square metres (Figure 2.1).

2.1.2          The KTCDA comprises several elements as well as the Kennedy Town Incineration Plant (KTIP).  The main operations at the Kennedy Town Abattoir (KTA) ceased and relocated to new facilities at Sheung Shui in the autumn of 1999.  The KTA includes an incinerator for disposal of animal carcasses and waste that is managed by EPD.

2.1.3          Part of the former EMSD Depot that forms part of the KTCDA has been leased to New World First Bus (NWFB) for bus maintenance and refuelling, under a short-term tenancy.  The remainder is leased as a car / lorry park (CP).  These facilities will remain in operation until Site possession is required for the project.

2.1.4          The former Kennedy Town Wholesale Market has been relocated and this area has been recently remodelled as a park and sitting out area adjacent to Victoria Road.  This is known as the Cadogan Street Temporary Garden (CSTG).

2.1.5          Urban Services DepartmentFood and Environmental Hygiene Department (FEHD) have a refuse collection point (RCP) between the park and the abattoir at Sai See Street.

2.1.6          At this stage the KTCDA includes:

·               Kennedy Town Incineration Plant (KTIP);

·               Kennedy Town Abattoir (KTA);

·               New World First Bus Depot (NWFB);

·               Car / lorry park (CP);

·               USD FEHD Refuse Collection Point (RCP); and

·               Cadogan Street Temporary Garden (CSTG).

2.1.7          The structures to be demolished are summarised in Table 2.1.

2.1.8          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.

2.1.9          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 extent of the Kennedy Town Development and 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 for R7, is currently being considered by Government.  This further study may alter the future land use of the KTCDA.

2.1.10      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 late 2003.  Experience of other demolition sites and consultation with local contractors suggests that a twelve month programme for the demolition would be sufficient.  The soil remediation programme would follow the demolition and would last an additional six to eight months based on the current findings of the ground contamination investigation.

Table 2.1         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 stores.

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. *

                *See Section 2.2

2.2              Sensitive Receivers

2.2.1          This section identifies the sensitive receives (SRs) affected by the Project as defined in the EIAO and summarises the main implications of the SRs and infrastructure on demolition methods.  The implications for sensitive locations of explosive demolition are noted and these have been fully discussed in Appendix A.  Sensitive receivers and other constraints are shown in Figure 2.1.  The Outline Zoning Plan for the area is presented in Figure 2.2.

Sensitive Receivers at KTCDA

Residential, Government, Institutional and Community

2.2.2          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 been vacated.

·               The Housing Society development at Ka Wai Man Roadmid.

·               There are occupied residential buildings at Cadogan Street including Centenary Mansion.

2.2.3          Other premises in the low-rise blocks in Cadogan Street have been demolished.

2.2.4          Premises in the low rise blocks in Cadogan Street (south of Victoria Road) and two high rise blocks (Sai Wan New Mansion and Cheung Kat Mansion) near the URA development, will remain in operation by the time demolition of KTCDA takes place.

2.2.5          Manhattan Heights high rise development at Kennedy Town New Praya overlooks the Site and is now occupied.  As such it is considered as a sensitive receiver.

2.2.6          There are other residential blocks further west along Victoria Road (e.g. Huncliff Court) that would be shielded by the intervening structures such as the China Merchants Wharf Godown and other industrial buildings on Victoria Road.

2.2.7          There are Government, Institutional and Community uses at St Luke’s Church School, St Luke’s Settlement, Jockey Club Clinic, Victoria Mortuary and the Bayanihan Centre.

2.2.8          St Luke’s Church School on Ka Wai Man Road and both St Luke’s Settlement and Jockey Club Clinic will remain in operation at the time of demolition for KTCDA.

2.2.9          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.

Other Sensitivities near KTCDA

NWFB

2.2.10      The New World First Bus Depot may require relocation  prior to the demolition.  However this is not material to the EIA as it is not defined as an SR.  Nevertheless the project proponent may need to liase with NWFB so that they may make provisions for these facilities at a later stage.  Diesel fuel storage tanks and other lubrication oil storage at NWFB are dealt with as part of the land contamination assessment and remediation action plan.

RCP

2.2.11      It has been suggested by the Food and Environmental Hygiene Department that the RCP at Sai See Street should be maintained throughout the demolition process.  The area of Sai See Street leading up to the RCP and the RCP itself would need to be excluded from the demolition in the usual way by means of a perimeter noise barrier running around Sai See Street and the RCP.  Such exclusion would make manoeuvring more difficult as the excluded area would effectively bisect much of the southern part of the Site and restrict transit from east to west.  Whereas it is not possible to establish, in detail, the possible impact of this on the demolition programme, common sense suggests that whereas reasonable areas would remain for manoeuvre in most other parts of the Site, the overall impact would not necessarily make major impacts on the programme.  However in order to simplify the demolition works the preference (on demolition grounds alone) would be to relocate the RCP and include the RCP site in the demolition site, unless an alternative location cannot be found.

2.2.12      The RCP adjacent to the CSTG in Cadogan Street is a lightweight prefabricated structure that could be relocated if necessary.  However LCSD have commented that the CSTG should remain open if at all possible to avoid the expense of reprovisioning.  The retention of the RCP at its present location may not necessarily be the most convenient arrangement for the demolition (as it would mean retaining the access along Sai See Street).  However, the access road and RCP area should be able to be excised from the demolition site without major inconvenience to the demolition process.  As there are no buildings immediately adjacent to the RCP routine procedures and precautionary measures carried out in line with the Draft Code of Practice for Demolition of Buildings (DCDB, Buildings Department 1998) will avoid impacts on the operation of the RCP.  This can take place within the routine for good overall project management of a demolition under the Hong Kong guidelines.

Road Traffic

2.2.13      Road traffic access must be maintained for residential and commercial uses at Kennedy Town.  There are potential concerns about the potential impact of traffic to and from the demolition site on the local network.

2.2.14      Access must be maintained for commercial uses at China Merchants Wharf and Godown, the Kennedy Town public transport terminus, Victoria Public Mortuary, industrial buildings, residences on Victoria Road, the petrol station on Victoria Road and the Island West Refuse Transfer Station.

2.2.15      Whereas the exact volume of waste to be disposed of has not yet been determined, estimates indicate that up to about forty lorries per day would be required.  Therefore it is estimated that during the peak of demolition process fewer than ten heavy vehicles per hour would be required to remove waste from the Site.  It is considered that this level of additional traffic could be absorbed into the surrounding network without significant impact (Section 6.4.1 refers).

Marine Traffic

2.2.16      An alternative method would be to use barges to remove waste in order to reduce overall road traffic impacts.  However in such a case, access would need to be Access must be maintained for vessels accessing the pier at China Merchants Wharf and Cadogan Street wharves and interference to the Victoria Harbour marine traffic must be minimised. Marine Department indicated that it would be preferable to avoid impacts in this busy marine area.  As  Although local aassessments indicate that additional waste disposal road vehicles could be absorbed into the surrounding road network without undue inconvenience, marine access is not required., it has been suggested that barges could be used to remove waste in order to reduce overall road traffic impacts.  Such a proposal would require a Marine Traffic Impact Assessments (MTIA) and is outwith the SB

Other Issues

2.2.17      The revised alignment for Route 7 and the extent of the Kennedy Town Developments are currently under review but at present the programme of these developments is unlikely to be advanced before the target completion date for demolition of KTCDA.  At this stage these proposals are not thought to have any impact on the Project.

2.3              Options for Demolition

Demolition Methods

2.3.1          The draft Code of Practice for Demolition of Buildings (DCDB, Buildings Department 1998) identifies several main methods of techniques for demolition including:

·         Top down methods by jack hammer, percussive or hydraulic breakers;

·         Wrecking Ball;

·         Implosion;

·         Saw Cutting and Drilling;

·         Non explosive demolition agents (NEDA);

·         Thermal lance; and

·        Water jet.

Implosive Methods (blasting)

2.3.2          Implosion does not offer any potential reduction in polluting impacts in the form of noise, vibration and dust (DCDB) and is not efficient for slabs and walls that will require demolition at KTCDA.   Site investigations have shown asbestos containing materials (ACM) are present at KTCDA (Section 3).  Therefore the preferred method of demolition should adopt non-blasting approach and implosive demolition using a blasting approach has been ruled out as an option for demolition.  The asbestos investigation and abatement plans are described in detail in the dedicated Asbestos Study Report.

Top-Down Methods

2.3.3          Top-down methods are applicable and efficient for all types of structure.  Typical jack-hammers can reduce vibration and hydraulic breakers can reduce noise (ref. DCDB).  However, machine mounted percussive breakers and toppling or breaking away structures by large machinery do not offer any potential reduction in dust, noise or vibration emissions (DCDB).  Whereas these methods may not be used exclusively, in order to assume a worst case scenario, a variety of these typical methods can be assumed to be used at KTCDA.

Wrecking Ball

2.3.4          This method is generally suitable for dilapidated buildings but would not be applicable in this case where the clear space to the edge of the Site is limited in places and structures have substantial steel reinforcement.

Other Methods

2.3.5          Potential polluting impacts in the form of noise, vibration and dust can be reduced by using methods such as circular saw cutting, wire saw cutting, and stitch drilling which are effective for all structures and can reduce vibration, noise and dust.  Non explosive demolition agent (NEDA) can also reduce vibration, noise and dust but is not applicable to slabs and walls.  The use of thermal lance and or high-pressure water jets would not generally be recommended unless there are no other viable alternatives.  Whereas a selection of the above processes may be used by the demolition contractor for specific locations, these methods would generally result in lesser impacts (DCDB) and their use should not be precluded by limiting plant to be used on Site to that used in the assessments.  However for the purpose of the environmental assessment these techniques are not assumed to be adopted in order that a worst possible case scenario is assessed.

Reception Piers

2.3.6          The recommended choice of demolition methods for the marine reception platforms and piers is top down method using saw cutting and lifting, in line with the DCDB, which will avoid the disturbance of any marine mud.

Preferred Methodology

2.3.7          The preferred demolition methodology is discussed in full in Appendix A.  A variety of top-down methods are assumed to be used and various articles from a suite of powered mechanical equipment has been assumed to be in use at various locations across the Site throughout the demolition.  The use of jack-hammers and hydraulic breakers is efficient and noise and dust impacts can potentially be controlled by a range of practical mitigation measures (e.g. noise barriers, dust control) familiar to the construction industry in Hong Kong.  In addition, the statutory provisions under the Noise Control Ordinance and Air Pollution Control Ordinance control noise and dust from such operations.  Due to the presence of ACM the preferred method of demolition must adopt non-explosive approach.  The asbestos investigation and abatement plans are described in detail in the dedicated Asbestos Study Report that has been reviewed by EPD.

Removal of Waste

2.3.8          The options for removal of waste relevant to this Site include use of marine barges and conventional lorries.

Marine Barges

2.3.9          The use of barges could reduce overall road traffic impacts, however loading at the waterfront would introduce the possibility of dust and waste being dropped into the sea.  Whereas there are reception piers at the waterfront which could be used as barging points the potential for loss of waste and consequent water pollution from these sources can be eradicated by the use of other means to transport waste.  Such access would also be complicated by the need to avoid v