7. Waste Management Implication and Land Contamination Assessment

7.1 Introduction

7.1.1 This section identifies the potential waste and land contamination likely to arise during construction and operation of the Project. The potential environmental impacts concerning their handling, collection and disposal will be assessed in accordance with the criteria and guidelines given in Annexes 7 and 15 of EIAO-TM, while the potential environmental impacts of land contamination will be assessed in accordance with the criteria and guidelines given in Sections 3.1 and 3.2 of Annex 19 of EIAO-TM.

7.1.2 At this planning stage, appropriate disposal methods for each type of waste are identified, and opportunities for waste reduction, reuse and recycling are considered. Environmental mitigation measures are recommended to mitigate the environmental impacts identified.

7.1.3 On the other hand, as the Depot will be constructed on a reclaimed land with development previously, the potential for contaminated land which could cause impacts during construction phase has also been assessed.

7.1.4 In addition, the operation of the proposed Depot will involve on-site storage, delivery and usage of chemicals, lubricants and chemical wastes. The associated potential of land contamination during operation phase would also be evaluated.

7.2 Environmental Legislation and Guidelines

General Waste Management

7.2.1 The following legislations are related to the handling, treatment and disposal of waste in Hong Kong, and will be considered in the assessment of potential impacts and waste management:

· Waste Disposal Ordinance (Cap 354);

· Land (Miscellaneous Provisions) Ordinance (Cap 28); and

· Public Health and Municipal Service Ordinance (Cap 132) – Public Cleansing and Prevention of Nuisances By-laws.

7.2.2 The following subsidiary regulations of the Waste Disposal Ordinance are also related:

· Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap 354N); and

· Waste Disposal (Chemical Waste) (General) Regulation (Cap 354C).

Waste Disposal Ordinance (Cap 354)

7.2.3 The Waste Disposal Ordinance (WDO) prohibits any unauthorised disposal of wastes. Construction waste, defined under Cap. 354N of the WDO means any substance, matter or thing that is generated from construction works and abandoned, whether or not it has been processed or stockpiled before being abandoned, but does not include any sludge, screenings or matter removed in or generated from any desludging, desilting or dredging works. Under WDO, waste can be disposed of only at designated waste disposal facilities licensed by the Environmental Protection Department (EPD).

Waste Disposal (Chemical Waste) (General) Regulation

7.2.4 Chemical wastes include unwanted substances or chemicals causing pollution or impose a danger to health or risk of pollution to the environment. A person should not produce, or cause to be produced, any chemical wastes unless he/she is registered with the EPD. Chemical wastes must be treated using on-site plant as licensed by the EPD or with engaging a licensed collector to transport the wastes to a licensed facility. For each consignment of wastes, the waste producer, collector and disposer must sign all relevant parts of a computerised trip ticket so as to trace wastes from production to disposal.

7.2.5 This regulation also prescribes the storage facilities to be provided on-site including the labeling and warning signs. To minimise the risks of pollution and danger to human health and life, waste producers are required to prepare and make available written emergency procedures for any spillage, leakage or accidents arising from storage of chemical wastes. The waste producers must also provide employees with training for such procedures.

Waste Disposal (Charges for Disposal of Construction Waste) Regulation

7.2.6 Under the WDO and the Charging Regulation, wastes can only be disposed of at designated waste disposal facilities licensed by EPD. Schedule 5 of Regulation defines that inert construction waste includes rock, rubble, boulder, earth, soil, sand, concrete, brick, tile, masonry or used bentonite. According to Schedule 6 of the Regulation, construction waste delivered to a landfill for disposal must not contain more than 50% by weight of inert material while those to a sorting facility for disposal must contain more than 50% by weight of inert material. Whereas construction waste delivered to a public fill reception facility for disposal must consist entirely of inert material.

7.2.7 For construction work with a value of more than HK$1 million, the main contractor is required to establish a billing account at the EPD before transporting the construction waste to the designated waste disposal facilities (for example, landfill and public fill). The vessels for delivering construction waste to the public fill reception facilities require prior approval from the Public Fill Committee (PFC). Any breach of these regulations may lead to a fine and/or imprisonment.

Land (Miscellaneous Provisions) Ordinance (Cap 28)

7.2.8 The inert portion of Construction and Demolition (C&D) materials (including rocks, soil, broken concrete, building debris, etc.) may be taken to public fill reception facilities (PFRFs). PFRFs usually form part of land reclamation schemes and are operated by the Civil Engineering and Development Department (CEDD) and others. The Land (Miscellaneous Provisions) Ordinance requires individuals or companies who deliver public fill to PFRFs to obtain Dumping Licences. The licences are issued by CEDD under delegated authority from the Director of Lands.

7.2.9 Individual licences and windscreen stickers are issued for each vehicle involved. Under the licence conditions, PFRFs will only accept inert construction waste. In addition, in accordance with paragraph 12 of the Development Bureau (DevB) Technical Circular (Works) TC(W) No.6/2010, PFC will advise on the acceptance criteria. The material will, however, be free from marine mud, household refuse, plastic, metal, industrial and chemical wastes, animal and vegetable matter and any other materials considered unsuitable by the PFRF supervisor.

Public Cleansing and Prevention of Nuisances Regulation

7.2.10 This regulation provides further control on the illegal dumping of litter or waste in streets and public places (including water courses, streams, channels etc). Offence to this regulation would result in a fine and/or to imprisonment.

Other Relevant Guidelines

7.2.11 The following guidelines are also relevant to waste management in Hong Kong:

· Code of Practice on the Packaging, Labeling and Storage of Chemical Wastes (1992), EPD ;

· Works Branch Technical Circular (WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site;

· WBTC No. 2/93, Public Dumps;

· WBTC No. 2/93B, Public Filling Facilities;

· WBTC Nos. 25/99, 25/99A and 25/99C, Incorporation of Information on Construction and Demolition Material Management in Public Works Subcommittee Papers;

· WBTC No. 12/2000, Fill Management;

· WBTC Nos. 6/2002 and 6/2002A, Enhanced Specification for Site Cleanliness and Tidiness;

· WBTC No. 11/2002, Control of Site Crusher;

· WBTC No. 12/2002, Specification Facilitating the Use of Recycled Aggregates;

· Environment Transport and Works Bureau Technical Circular (Works) (ETWB TC(W)) No. 33/2002 Management of Construction and Demolition Material Including Rock;

· ETWB TC(W) No. 19/2005 Environmental Management on Construction Sites; and

· DevB TC(W) No. 6/2010, Trip Ticket System for Disposal of Construction & Demolition Materials, Development Bureau.

7.2.12 The ETWB TC(W) No. 19/2005 sets out the policy and procedures requiring contractors to prepare and implement an Environmental Management Plan (EMP) to abate environmental nuisances on construction site and reduce C&D Materials to be disposed of during construction.

Contaminated Land

7.2.13 The following legislations are related to the land contamination issues concerning handling, treatment and disposal of contaminated materials:

· Waste Disposal Ordinance (Cap 354);

· Waste Disposal (Chemical Waste) (General) Regulation (Cap 354C); and

· Dangerous Goods Ordinance (Cap 295).

7.2.14 The following EPD publications provide guidance on the land contamination assessment in this Assignment:

· Practice Guide for Investigation and Remediation of Contaminated Land;

· Guidance Note for Contaminated Land Assessment and Remediation; and

· Guidance Manual for Use of Risk-Based Remediation Goals (RBRGs) for Contaminated Land Management.

7.3 Assessment Methodology

Waste Management

7.3.1 The waste management implication will be assessed in accordance with the criteria and guidelines given in Annexes 7 and 15 of the EIAO-TM.

7.3.2 The waste management hierarchy is applied in the assessment on waste management implication and mitigation measures. It is a concept showing the priority of different waste management methods in following order:

· Avoidance;

· Minimisation;

· Recycling/reuse;

· Treatment; and

· Disposal.

7.3.3 Opportunities for reducing waste generation are identified based on the following factors:

· Avoid or minimise waste generation in design;

· Adopt segregation of waste materials;

· Reuse and recycling; and

· Divert waste to public dumps or other construction sites.

7.3.4 The nature and likely quantities as well as the environmental implications of handling, collection, transportation and disposal of each waste material type generated from the Project during construction and operation phases are evaluated. Preventive and mitigation measures are also proposed if applicable. This assessment covers potential hazard, air and odour emissions, noise, wastewater discharge and public transport.

7.4 Identification of Potential Waste Management Implication

Construction Phase

Details of Work Activities

7.4.1 A number of construction activities will generate different type of wastes. As described in Section 3 of this EIA report, the key construction activities of the Project mainly comprises foundation works by piling and superstructure construction. Based on the nature and disposal options, the wastes generated would be broadly classified into the following categories:

· Construction and Demolition Materials (C&D Materials) suitable for public fill;

· Construction and Demolition Waste (C&D Waste) not suitable for public fill;

· Chemical waste; and

· General refuse.

Construction and Demolition Materials/ Waste

7.4.2 It is noted that the CEDD site offices recently occupied the Site have been just being returned to Lands Department. The existing structures are being cleared and the Site will be vacant before handed over to FEHD for the development of the Depot. Therefore no demolition works would be involved for this Project. In addition, as the Site is relatively flat and uniform, the major site formation works would not be required for this Project, whilst main preparation works would include removal of paved ground for installation of underground utilities and re-pavement. The amount of C&D Materials/ Waste generation during the site clearance is hence expected to be limited.

C&D Materials

7.4.3 C&D Materials generated during construction will comprise materials that are suitable for reuse on-site or off-site as public fill. As driven H-pile would be adopted, it is expected the waste from piling would be insignificant. The major source of C&D Materials will be excavated fill materials from near-ground sub-surface, mainly from the construction of substructure members like pile caps, ground beams and underground utilities and tanks.

7.4.4 Moreover, the site specific ground investigation carried out for this project in May to July 2012 revealed that out of the ten drillholes and two trial pits, only one drillhole (BH6) encountered marine sediment/deposit at a depth 19 to 21mbgl. The drillhole record of BH6 is provided in Appendix 7-1. As anticipated excavation associated with this project will be isolated and is likely at shallow depth of less than a few meters, it would not encounter any marine deposit that was present at a much greater depth.

7.4.5 Since detailed design of the foundation works and building construction is yet not available at this stage, it is only possible to preliminarily estimate the amount of excavated soil and other C&D Materials.

7.4.6 A summary of the C&D Materials anticipated to arise from the Project is provided in the following Table 7-1.

Table 7-1 Summary of C&D Materials Arising from the Project

Material Type	Estimated Quantity	Potential Sources of Materials
Used asphalt and concrete	2,500m³	Removal of paved ground with depth of 0.3m during site formation
Excavated soil (e.g. sand, gravel)	35,500m³	Pre-boring works and excavation works for pile foundation works and for the construction of substructure members
Others (e.g. concrete debris, aggregate, metal)	2,800m³ *	Building construction works (e.g. concrete footing, metal formwork and falsework for the beam and slab structure)
TOTAL	40,800m³

Remark: * Based on the proposed GFA of the building and an assumed C&D generation rate of 0.1m³m^-2 (Reference: “Reduction of Construction Waste Final Report”, Hong Kong Polytechnic, 1983)

C&D Waste

7.4.7 C&D Waste is not suitable for reuse and requires disposal to licensed landfill facilities. This kind of waste generated from construction activities include:

· Cleared vegetation;

· Wood from formwork;

· Damaged or contaminated construction materials;

· Equipment and vehicle maintenance parts; and

· Materials and equipment wrappings etc.

7.4.8 The volume of C&D Waste, such as maintenance and packaging waste being generated by the Project will be subject to specific construction procedures and site practices. The estimated amount of C&D wastes generated during site clearance and construction of superstructure works would be small and expected to be 300m³ with careful design, planning, good site management and control of ordering procedures etc.

Chemical Waste

7.4.9 Chemical waste includes any scrap materials or unwanted substances specified under Schedule 1 of Waste Disposal (Chemical Waste) (General) Regulation if such a substance or chemical occurs in such a form, quantity or concentration that causes pollution or constitutes a danger to health or risk of pollution to the environment.

7.4.10 Chemical waste likely to arise from the construction activities for the Project includes:

· Scrap batteries or acid/alkali from construction plant maintenance activities;

· Used paints, engine oils, hydraulic fluids and waste fuel;

· Spent mineral oils/cleansing fluids from machineries; and

· Spent solvents/solutions, some of which may be halogenated, from equipment cleansing activities.

7.4.11 The amount of chemical waste that will be generated from the construction work will depend on the Contractor’s on-site maintenance practices and the number of mechanical plant and vehicles used on-site. Regarding the nature of the construction activities involved, chemical waste such as lubricating oil or solvent generated are not expected to be in large quantity. It is expected that less than 50L/ month and hence approximately 1.3m³ of chemical waste will be generated.

General Refuse

7.4.12 The workers in the construction site and the site office will generate a variety of general refuse which requires disposal. It consists mainly of food waste, aluminum cans, waste paper etc.

7.4.13 Since no information in regard to the number of workers on-site is available at this preliminary stage, a maximum of 100 workers working simultaneously at and a waste generation rate of about 0.65kg per person are assumed. It is estimated that the daily amount of general refuse that would be generated is in the order of 65kg.

Operational Phase

7.4.14 The operational phase of the Project is not expected to generate any significant quantities of general or other waste. The key concern of waste type for waste management during the operational phase would be chemical waste.

Chemical Waste

7.4.15 The chemical waste likely to arise in the operation of the Depot would mainly be from repairing and maintenance activities of vehicles, which includes scrap batteries, used engine oils, lubricating and hydraulic fluids and spent mineral oils/ cleaning fluids from mechanical machinery.

7.4.16 A summary of the chemical waste anticipated to arise from the Project is provided in Table 7-2 below.

Table 7-2 Summary of Chemical Waste Arising from the Project

Chemical Type	Estimated Quantity
Waste batteries	160 nos. per year
Used oil/lubricant	3,000 litres per year

General Refuse

7.4.17 The quantities of general refuse arising from the Project at the operation stage will be low and mainly arise from office activities.

Timing of Waste Generation

7.4.18 Based on the preliminary programme, the first 3 months would be for site mobilisation, whilst the following 7 and 6 months for foundation works and superstructure respectively. In addition, the finishes would spend the remaining 9 months, which are shown in Appendix 3-1. A tentative estimated timing of waste arising is shown in Table 7-3.

Table 7-3 Tentative Estimated Timing of Waste Arising

Type of Waste	Months
Construction Phase
C&D Material	M1 to M10
C&D Waste	M1 to M16
Chemical Waste	Entire construction phase
General Refuse	Entire construction phase
Operation Phase
Chemical Waste	Entire operation phase
General Refuse	Entire operation phase

7.5 Waste Management Implication

7.5.1 The evaluation of the potential environmental impacts associated with each type of waste arising is described below:

Construction Phase

C&D Materials

7.5.2 C&D Materials generated by the Project has been explored for reuse on-site or off-site. All scrap metals will be collected for recycling, while a portion of sand and aggregate would also be reused on-site. The possibility of maximising the reuse of excavated soil would be explored during the detailed design. One-third of the excavated soil (approximately 12,000m³) would be reused as backfill upon the completion of excavation works for substructure.

7.5.3 The surplus of excavated soil and construction debris is proposed to be delivered to off-site public filling areas or other reclamation areas. Based on the preliminary construction programme, duration for substructure works will be last for 6 months. Assuming 24 working days monthly and a peak factor of 2, the daily quantity of excavation materials to be transported is estimated to be 400m³/day. Hence, approximately 5 truck load per hour is required to handle daily quantity of excavated material for delivery to off-site public filling areas or other sites for reuse. The impacts from transportation off-site would be limited, in view of the said limited traffic induced.

7.5.4 The key secondary environmental concern associated with the handling of the excavated material is expected to be potential fugitive dust emission and noise impact. With the implementation of the recommended dust and noise control/ mitigation measures presented in the air quality and noise sections in Sections 4 and 5, such as covering and stockpiling materials to avoid dust and other nuisance impacts, these secondary environmental factors are not expected to be a concern.

7.5.5 The Project Proponent should timely notify the estimated volumes of excavated materials to be generated and notify and make agreement with the Public Fill Committee (PFC) on the disposal of surplus inert C&D Materials. C&D Materials should be segregated from other wastes to avoid contamination and to ensure acceptability at public filling areas or reclamation sites. The surplus C&D Materials would be reused within the site as much as possible and the Project Proponent should obtain confirmation from PFC on the proposed disposal arrangement before the commencement of the construction works.

7.5.6 No construction work is allowed to proceed until all issues on management of C&D Materials have been resolved and all relevant arrangements have been agreed endorsed by the relevant authorities including PFC and EPD.

C&D Waste

7.5.7 In view of the small quantities of C&D Waste due to reuse of C&D Material, with proper waste management and measures implemented to minimise the generation of waste, e.g. control of ordering procedures, prohibition of on-site burning of wooden waste, significant impacts associated with its handling, storage or disposal would not be expected.

Chemical Waste

7.5.8 Chemical waste may pose environmental, health and safety hazards if not stored and disposed appropriately in strict accordance with the Waste Disposal (Chemical Waste) (General) Regulation and the “Code of Practice on the Packing, Labeling and Storage of Chemical Waste”. These hazards may include:

· Toxic effects to workers;

· Adverse effects on air quality, water quality and land contamination due to spillage;

· Hazards of fire; and

· Disruption of downstream sewage treatment works if the chemical waste enters the sewerage system.

7.5.9 Regarding the nature of the construction activities involved, it is anticipated that the quantity of chemical waste arising during the construction of this Project would be small. Provided that the handling, storage and disposal of chemical wastes are in accordance with the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes, significant impacts would not be anticipated.

7.5.10 Nevertheless, the Contractor should register to the EPD as a Chemical Waste Producer in strict accordance with the Waste Disposal (Chemical Waste) (General) Regulation. Chemical waste has to be stored on-site with suitable containers so that leakage or spillage is prevented during the handling, storage, and subsequent transportation. The chemical waste should be collected by licensed collectors for subsequent disposal at licensed chemical waste disposal facilities, for example the Tsing Yi Chemical Waste Treatment Centre.

General Refuse

7.5.11 The storage of general refuse has the potential to cause adverse environmental impacts, e.g. odour nuisance if the waste is not collected frequently, windblown litter, water quality impacts if the waste enters water bodies, visual impacts, etc.

7.5.12 Waste storage areas in construction site without proper management may also attract pests, vermin and other disease vectors. Disposal of waste at areas other than approved refuse transfer stations and landfills can also lead to similar adverse impacts.

7.5.13 It is recommended that the Contractor should employ a reliable waste collector to collect general refuse from the construction site on a daily basis where appropriate to minimise the potential odour, pest and litter impacts. Moreover, the segregation of aluminum cans or other recyclable material for recycling should be considered as far as practicable.

7.5.14 With the small quantity of general refuse and the appropriate practice to handle the waste, potential environmental impacts caused by the storage, handling, transport and disposal of general refuse would be expected to be insignificant.

Overall Waste Management

7.5.15 Referring to the waste management hierarchy presented in Section 7.3.2, the generation of C&D Materials/ Waste should be minimised by avoiding its generation and reusing within the Project wherever practicable. The following methods are adopted in this Project:

(1) Minimising Generation of C&D Materials/ Waste:

· Section 2 of this EIA Report presented that steel-H driven piling instead of bored piling is to be adopted for the foundation works, which leads to less generation of excavation materials and waste.

· Reduce the use of tropical hardwood by using metal hoarding, standardisation of the structural elements for encouraging the use of system formwork and metal formwork.

(2) Maximising Reuse of C&D Materials/ Waste:

· Inert C&D Materials from pile foundation, metal formwork, falsework, etc will be reused both on-site and off-site as far as practicable, e.g. scrapped steel bars to be recycled or earth materials, concrete debris and aggregates for backfilling.

· Recycled aggregates will be used, subject to availability, for hardcores, sub-base, on-grade slabs and planters.

· Crushed rock fines instead of natural sand should be used to produce ordinary concrete.

7.5.16 This hierarchy should be strictly followed and applied in evaluating the waste management options in order to maximise the waste reduction and often reduce costs, for example, by controlling, reducing or eliminating over-ordering of construction materials. Records of quantities of wastes generated, recycled and disposal (locations) should be properly documented.

7.5.17 The requirements as stipulated in the ETWB TC(W) No.19/2005 “Environmental Management on Construction Sites” and the other relevant guidelines should be included in the Particular Specification for the Contractor as appropriate.

7.5.18 To ensure appropriate handling of different C&D waste types, the Contractor should be required to implement the recommended waste management measures through establishing a Waste Management Plan (WMP) in accordance with the ETWB TC(W) No.19/2005 so as to provide an overall framework of waste management and reduction. The WMP should be submitted to the Project/ Site Engineer prior to the construction commencement of the Project for approval and include the followings:

(i) Waste management policy;

(ii) Record of generated waste;

(iii) Waste reduction target;

(iv) Waste reduction programme;

(v) Role and responsibility of waste management team;

(vi) Benefit of waste management;

(vii) Analysis of waste materials;

(viii) Reuse, recycling and disposal plans;

(ix) Transportation process of waste products; and

(x) Monitoring and action plan.

7.5.19 A trip-ticket system should be established to comply with DevB TC(W) No. 6/2010 and Waste Disposal (Charges for Disposal of Construction Waste) Regulation in order to monitor the disposal of inert C&D Materials at public fill and the remaining C&D Waste to landfills, and control fly-tipping. A trip-ticket system should be included as one of the contractual requirements and implemented by the Contractor. The Project/ Site Engineer should regularly audit the effectiveness of the system.

7.5.20 A recording system for the amount of waste generated, recycled and disposed (including the disposal sites) should be established.

7.5.21 The Contractor should also provide proper training to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling.

7.5.22 No waste should be burnt on-site. Disposal of waste at unlicensed location e.g. natural habitat should be prohibited. The Contractor should propose the final disposal sites in the EMP and WMP for approval before implementation.

Operational Phase

Chemical Waste

7.5.23 Provided that chemical waste generated during operation phase is managed in accordance with the requirements under the “Code of Practice on the Packaging, Labelling and Storage of Chemical Waste” published by EPD, unacceptable impacts should not be caused.

7.5.24 Oily substances accumulated inside oil/petrol interceptors in the vehicle washing and repairing areas should be regularly removed and transported away by licensed collectors for proper disposal.

General Refuse

7.5.25 As the amount of general refuse which is mainly arising from office or maintenance activities is expected to be small, potential environmental impacts caused by the storage, handling, transportation and disposal of general refuse is expected to be insignificant.

7.6 Mitigation Measures

Construction and Operation Phases

7.6.1 To avoid or minimise potential adverse environmental impacts associated with the handling, collection, transportation and disposal of waste arising from the construction and operation of the Project, the following mitigation measures are recommended:-

(1) Good Site Practices

· Purchase of construction materials should be carefully planned in order to avoid over-ordering and wastage;

· Appropriate measures to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;

· Stockpiled materials should be covered by tarpaulin and /or watered as appropriate to prevent windblown dust and surface run off;

· The Site and surroundings should be kept tidy and litter free;

· Different areas of the sites should be considered for such segregation and storage;

· Carry out regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors; and

· Proper storage and site practices to minimise the potential for damage or contamination of construction materials.

(2) C&D Materials/ Waste

· On-site sorting and reuse excavated fill material should be carried out for backfilling and reinstatement;

· Provisions in contract documents should be made to allow and promote the use of recycled aggregates where appropriate;

· Standard formwork or pre-fabrication should be used as far as practicable so as to minimise the C&D Materials arising;

· Concrete and masonry should be crushed and used as fill materials where practicable;

· Steel reinforcement bar should be collected for use by scrap steel mills;

· Metal fencing or building panels, which are more durable than wooden panels, are recommended to be used for any construction site hoarding erected;

· Any wooden boards used in site fencing on-site or off-site should be reused;

· C&D Materials should be recycled as much as possible on-site;

· Public fill and C&D Waste should be segregated and stored in different containers or skips to enhance reuse or recycling of materials and their proper disposal; and

· Excavated material in trucks should be covered by tarpaulins to reduce the potential for spillage and dust generation.

(3) Chemical Waste

· Chemical waste producers should be registered with the EPD;

· Chemical waste should be handled in accordance with the “Code of Practice on the Packaging, Handling and Storage of Chemical Wastes” including but not limited to the followings:

- Good quality containers compatible with the chemical wastes should be used and maintained in good conditions and securely closed, with incompatible chemicals be stored separately.

- Appropriate labels should be securely attached on each chemical waste container in English and Chinese according to the instructions prescribed in Schedule 2 of the Regulations.

- A licensed collector to transport and dispose of the chemical wastes should be employed by the Contractor, to either the Chemical Waste Treatment Centre at Tsing Yi, or another licensed facility.

· Adequate numbers of portable toilets should be provided for on-site workers during construction and maintained in reasonable states, which will not deter the workers from utilising them; and

· Waste oils, chemicals or solvents should not be discharged to drain; and

· Routine cleaning and maintenance programme for drainage systems, sumps and oil interceptors during operation.

(4) General Refuse

· Sufficient dustbins should be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws;

· Sufficient enclosed bins should be provided for general refuse, food and beverage waste to reduce odour, pest and litter impacts;

· General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes;

· A reliable waste collector should be employed to clear general refuse from the construction site on a daily basis and disposed of to the licensed landfill or refuse transfer station;

· Office wastes can be reduced by recycling of paper if such volume is sufficiently large to warrant collection. Participation in a local collection scheme by the Contractor should be advocated;

· Waste separation facilities for paper, aluminum cans, plastic bottles, etc should be provided on-site and collected by individual collectors should be encouraged; and

· Separate labelled bins should be provided to help segregate this waste from other general refuse.

7.7 Land Contamination Assessment

Assessment Methodology

7.7.1 The land contamination assessment was conducted with reference to the “Practice Guide for Investigation and Remediation of Contaminated Land” issued by EPD. The general procedures of the assessment include, if consider necessary during each investigation stage:-

1. Conduct Site Appraisal to collect information

If require,

2. Prepare a Contamination Assessment Plan for EPD approval

3. Conduct Site Investigation including sampling and laboratory tests

4. Prepare Contamination Assessment Report/Remediation Action Plan for EPD approval

5. Conduct remediation works

6. Prepare a Remediation Report for EPD endorsement

Site Appraisal

7.7.2 In order to identify the potential contamination sources, if any, within the Site and its surroundings due to past and current uses, a site appraisal was conducted to review the existing and historical land uses that may impact the Site.

7.7.3 Information on site history and other available information related to the Site including aerial photographs were reviewed to ascertain the potential historical and current on-site and off-site activities that can result in contamination of the Site.

Review of Aerial Photographs and Historical Land Uses

7.7.4 The history of the Site was reviewed with the use of aerial photographs from Year 1991 to 2010, provided by Lands Department. In order to further understand the historical land uses, information request letter had been sent to Lands Department on 13 June 2012 and response was received on 5 July 2012. The result indicated that the Site is on a reclaimed land. It was occupied as carpark and container storage area in the past while recently served as site offices and associated storage for Civil Engineering and Development Department (CEDD) (just returned). The key findings of the review were summarised in Table 7-4.

Table 7-4 Summary of Historical and Current Land Uses

Years	Land Uses / Status
Before 1991	Sea
1991 to 1992	Reclamation
1993 to 2004	Cargo handling and vehicle storage
2005 to 2009	Public car-park for licensed container vehicles
2010 to recent	Site offices for public projects

7.7.5 The historical photographs and the correspondence on information request on past land uses are shown in Appendix 7-2.

Acquisition of Relevant Information from Government Departments and Power Company

7.7.6 In addition to information available from Lands Department, information request was also sent to EPD and Fire Services Department (FSD) to identify any records of chemical spillage/ leakage accident as well as dangerous goods and incidents records respectively on 13 June 2012. Further request to CLP Power Hong Kong (CLP) was also sent on 17 July 2013 for Dangerous Goods and Chemical Wastes record at CLP Tai Kok Tsui Substation next to the Site.

7.7.7 The reply letter from EPD was received on 18 June 2012, revealing that no record of spillage/ leakage of chemicals within the Site was aware. Whilst the reply from FSD received on 22 June 2012 advised that neither records of dangerous goods license nor incidents of spillage/ leakage of dangerous goods were found at the Site. The correspondence is presented in Appendix 7-3. CLP also replied on 25 July 2013 that there was no record on the registration of dangerous goods/ chemical waste and chemical spillage/ leakage at Tai Kok Tsui Substation. The correspondence with CLP is provided in Appendix 7-3.

Site Walkover

7.7.8 Site walkover was carried out on 22 June 2012 at the Site occupied as the site offices and associated storage for three public projects managed by CEDD at the site of walkover. The details of the site walkover are provided in Appendix 7-4. As observed from the walkover, there was storage of trace amount of fuels, lubricants, solvents and chemicals at the area occupied under GLA TK-611 (which was registered as chemical waste producer with EPD). The condition of these three sites was generally acceptable despite there were trace oil and stains on the paved ground surface at the area occupied under GLA TK-628. The occupants were contractually required to carry out site clearance and restore the site condition before returning the site to the Government. Tai Kok Tsui substation was also observed to be concrete paved.

7.7.9 There was a minor rainwater with trace diesel overflow from the drip tray under the generator of the G.I. sub-contractor appointed by ArchSD after heavy rain at the area occupied under GLA TK-611. The dripped rainwater was absorbed by clothes and collected into a bucket and stored in Chemical Waste storage area. As site area are hard paved by concrete, leakage / spillage of diesel into soil underneath was not encountered.

Identification of Site Future Land Use

7.7.10 In accordance with the “Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management” by EPD, the corresponding nature of this proposed vehicle depot was determined as “Industrial”. Therefore, identification of contamination sources, exposure pathways and receptors for the proposed Site followed the Conceptual Site Model as illustrated in Figure B3 of the “Practice Guide for Investigation and Remediation of Contaminated Land” in order to ensure there are no additional pathways or receptors present for the Site and the appropriate Risk-Based Remediation Goals (RBRGs) can be applied.

Conclusion from Site Appraisal

7.7.11 Based on the findings from Site Appraisal, in view of the bund design at chemical storage areas and the concrete / asphalt paved ground which would be restored before handover, it was envisaged that potential contamination from the on-site chemical storage would be insignificant. Also, there were no potential contamination on the soil and groundwater arising from the past activities at the Site. Potential impact attributed to the Tai Kok Tsui Substation was also not envisaged. Therefore, subsequent environmental sampling and remediation at the construction phase are considered not necessary for the Site in this EIA Study.

7.8 Preventive Measures

Potential Land Contamination Sources from Operation Activities

7.8.1 With regard to the Depot nature of the Project, the potential sources of land contamination during operation were identified as follows:-

· Covered vehicle washing bays;

· Covered vehicle maintenance workshop including repair bays;

· Dangerous goods (DG) and chemical storage areas;

· Underground waste lubrication oil tanks; and

· Chemical wastes storage areas.

Preventive and Precautionary Plan

Paving of the Site

7.8.2 The Depot covering vehicle washing bays, maintenance workshop and storage areas for DGs, chemicals and wastes should be impervious and properly paved by concrete.

7.8.3 Installation of drainage management system including oil interceptor should be adequately designed and maintained.

Storage of Chemical and Chemical Wastes

7.8.4 All segregation, storage and handling of chemicals including raw chemicals, chemical wastes and DGs as classified under Dangerous Goods Ordinance should be in compliance with the requirements stipulated in “Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes” issued by EPD.

7.8.5 Bunded containment for the chemical and chemicals wastes should be adopted. Underground waste oil storage tank should be properly designed with double skin/ bottom. Regular inspection and maintenance should be conducted to avoid leakage from the containment and tank.

Emergency Procedures

7.8.6 Suitable absorbent materials shall be kept on site to deal with spills. When there is spillage/ leakage, immediate action should be taken to cover and contain the spillage/ leakage using suitable absorbing materials and containers respectively. All spillage should be reported to the Depot manager who should attend to the spillage and initiate any immediate actions required to protect workers and to confine and clean up the spillage.

7.8.7 The spilled area should be decontaminated. Water should be used to clean up the aqueous chemicals or wastes and water soluble organic wastes, whereas kerosene or turpentine should be used for cleaning up organic chemical wastes that are not soluble in water. The resultant wastes/ slurry should be treated as chemical waste and transferred to suitable containers for disposal.

7.8.8 Where the spillage/ leakage occur in an enclosed storage area, the materials should be transferred to suitable containers by appropriate equipment such as hand-operated pumps, scoops or shovels.

Record of Incidents

7.8.9 An incident report containing details of the incident including estimated amounts of spillage and actions taken if any, should be compiled by Depot manager as soon as possible after the incident. The evaluation of environmental impacts arising from the spillage and assessment on the effectiveness of measures taken should be based on the incident report such that improvement can also be made to the response procedures for future incident.

Procedures for Waste Disposal

7.8.10 Chemical wastes including spent or expired chemicals, paints, synthetic lubricants should be properly handled in accordance with the “Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes”, and collected by a licensed collector and disposed of at a licensed chemical waste treatment facility. Regular removal of waste from the Depot should be adopted to minimise the potential for land contamination by avoid prolonged storage of chemical wastes at the Site.

7.9 Residual Impacts

7.9.1 The Project is likely to result in the generation of a variety of wastes and require management and disposal of C&D material, chemical waste and general refuse. Provided that the wastes are managed by implementing all the recommended measures, no unacceptable adverse environmental impacts arising from the handling, storage, transportation or disposal of the wastes generated by the Project would be envisaged.

7.9.2 Moreover, there were no significant land contamination impacts during the construction and operation phases of the Project. Therefore, adverse residual impacts would not be anticipated.

7.9.3 With the implementation of recommended preventive and mitigation measures, adverse residual impacts are not anticipated for both the construction and operational phases.

7.10 Environmental Monitoring and Audit

7.10.1 It is recommended that regular auditing by an Environmental Team should be carried out during the construction phase of the Project to ensure waste are being managed with the appropriate procedures or practices in accordance to relevant legislation and waste management guidelines as well as those recommended in this EIA Report. The audits will examine all aspects of waste management including waste generation, storage, recycling, transport and disposal.

7.10.2 A WMP, as part of EMP, should be prepared in accordance with ETWB TC(W) No.19/2005 and submitted to the Project/ Site Engineer for approval. The recommended mitigation measures should form the basis of the WMP. The monitoring and auditing requirement stated in ETWB TC(W) No.19/2005 should be followed with regard to the management of C&D Materials.

7.10.3 As the land contamination at the Site was identified to be insignificant during construction and operation phases with the implementation of good site practice and design, no EM&A for contaminated land is recommended.

7.11 Conclusions

7.11.1 The waste streams that would be generated during the construction phase of the Project were identified and evaluated in terms of their quantity, type and nature etc. Opportunities for minimising waste generation via on-site sorting and reusing excavated fill materials are identified. Preventive measures have been recommended for the Contractor to implement during the construction phase to address any potential environmental impacts.

7.11.2 The waste streams that would be generated during the operation phase of the Project were also identified and evaluated. Measures to ensure proper treatment and disposal of these wastes have been made.

7.11.3 With regard to the historical land uses and current site condition, there was no sign of land contamination due to the past and current activities at the Site. For the future operation, as the Site will be paved and good practice for storage and handling of limited DGs, chemicals and chemical wastes will be followed, leakage of contaminants causing quantifiable adverse land contamination impacts would therefore not be anticipated.

7.11.4 Provided that the recommendations set out in this section are implemented, unacceptable environmental impacts would not be expected to arise from the handling, storage, transportation and disposal of wastes and chemicals during both the construction and operation of the Project.