11 Waste Management and land contamination

11.1 Introduction

11.1.1.1 This section identifies potential waste that may arise from the construction and operation of the Trunk Road T2 and assesses the potential environmental impacts associated with its handling and disposal, including the excavated marine deposit (sediment) potentially buried underneath the South Apron and Cha Kwo Ling works areas as shown in Figures 11.1a and 11.1b. Options of reuse, minimisation, recycling, treatment, storage, collection, transport and disposal of such wastes have been examined. Where appropriate, procedures for waste reduction and management have been considered, with environmental control measures to avoid or minimise impacts recommended.

11.1.1.2 In addition, part of the Trunk Road T2 project will be constructed on previously developed land lot currently occupied by PCCW and a short section of Cheung Yip Street, as shown in Figures 11.2a and 11.2b, which has the potential for contaminated land impacts during the construction of the Project that need to be assessed. The objectives of the contaminated land section are to summarise the findings of a land contamination assessment, which includes a desktop review of the existing information, findings of site investigation (SI) works undertaken, interpretation of the extent of land contamination based upon the findings, recommendations of any necessary remediation action and the way forward concerning any necessary further SI to ascertain the extent of land contamination, according to a Contamination Assessment Plan (CAP) previously endorsed by the Environmental Protection Department (EPD) and a Contamination Assessment Report (CAR).

11.2 Environmental Legislation, Guidelines and Standards

11.2.1 Waste Management

11.2.1.1 The following legislation is relevant to the handling, treatment and disposal of waste in Hong Kong and has been considered in assessing the potential impacts and their avoidance or mitigation:

· Environmental Impact Assessment Ordinance (Cap 499);

· Waste Disposal (Amendment) Ordinance (Cap 354);

· Dumping at Sea Ordinance (Cap 466);

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

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

11.2.1.2 Under the Waste Disposal (Amendment) Ordinance, some of the regulations that are, also, relevant to this EIA, include:

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

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

Waste Disposal (Amendment) Ordinance and the Waste Disposal (Charges for Disposal of Construction Waste) Regulation

11.2.1.3 The Waste Disposal (Amendment) Ordinance (WDO) prohibits unauthorised disposal of wastes. Schedule 5 of the Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Charging Regulation), also, defines that the inert construction waste includes rock, rubble, boulder, earth, soil, sand, concrete, brick, tile, masonry or used bentonite.

11.2.1.4 Under the WDO and the charging regulation, wastes can only be disposed of at designated waste disposal facilities licensed by the EPD. 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.

Waste Disposal (Chemical Waste) (General) Regulation

11.2.1.5 Chemical waste includes any scrap materials or unwanted substances specified under Schedule 1 of this 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.

11.2.1.6 A person shall not produce, or cause to be produced, any chemical wastes unless he/she is registered with the EPD, otherwise, it will be an offence and is liable to a fine and/or imprisonment. 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 of the wastes must sign all relevant parts of a computerised trip ticket so as to trace wastes from production to disposal.

11.2.1.7 This regulation also prescribes the storage facilities to be provided on-site including the labelling and warning signs. In order 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, and waste producers must also provide employees with training for such procedures.

Dumping at Sea Ordinance

11.2.1.8 The relevant legislation and guidelines for the disposal of contaminated sediment at marine disposal sites are listed below.

· Dumping at Sea Ordinance (Cap.466);

· Environment, Transport and Works Bureau Technical Circular (Works) No.34/2002 Management of Dredged /Excavated Sediment; and

· Works Bureau Technical Circular (WBTC) No. 12/2000 Fill Management.

11.2.1.9 The Dumping at Sea Ordinance (DASO) is the major statutory legislation to control dumping of sediment at sea and safeguards the water quality and ecology of the Hong Kong waters.

11.2.1.10 The ETWB TCW No.34/2002 was adopted in August 2002 to supersede Work Bureau Technical Circular (WBTC) 3/2000, which was promulgated for the purpose of assessing the disposal requirements for dredged sediment. The ETWB TCW No.34/2002 sets out the procedures for seeking approval to dredge/excavate sediment and the management framework for marine disposal of such sediment. It covers the approval of the dredging/excavation proposals and marine disposal of the dredged/excavated sediment. It does not cover the use of dredged/excavated sediment to form land, but such dredging and reclamation works must satisfy the requirements of the EIAO. Application for the approval of dredging/excavation proposals and allocation of the marine disposal space shall be made to the Secretary of Marine Fill Committee (MFC). The allocation of sediment disposal sites would not be considered until the need for removal of such sediment has been satisfactorily demonstrated. The rationale for sediment removal should, therefore, be provided to the Secretary of MFC for agreement.

11.2.1.11 The ETWB TCW No. 34/2002, also, establishes guidelines for the classification of sediment based on their contaminant levels, including:

· Metals (cadmium, chromium, copper, mercury, nickel, lead, silver and zinc);

· Metalloid (arsenic); and

· Organic micro-pollutants (polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and tributyltin).

11.2.1.12 There are two sets of chemical criteria for assessing the contamination levels of sediment:

· Lower Chemical Exceedance Level (LCEL); and

· Upper Chemical Exceedance Level (UCEL).

11.2.1.13 The LCEL is intended to represent levels below which adverse biological effects (or ecotoxicity) are considered to be unlikely. The UCEL, on the other hand, is intended to represent a level beyond which adverse biological effects are considered likely to occur. These criteria therefore represent a convenient means to broadly characterise sediment quality and identify potentially polluted sediments that might be of concern if they are disturbed in the course of the Project. The LCEL and UCEL for the contaminants of interest are presented in Table 11.1 below.

Table 11.1 Sediment Quality Criteria for Classification of Sediment under ETWB TCW No.34/2002

Contaminants	Lower Chemical Exceedance Level (LCEL)	Upper Chemical Exceedance Level (UCEL)
Metals (mg/kg dry wt.)
Cadmium (Cd) Chromium (Cr) Copper (Cu) Mercury (Hg) Nickel (Ni)* Lead (Pb) Silver (Ag) Zinc (Zn)	1.5 80 65 0.5 40 75 1 200	4 160 110 1 40 110 2 270
Metalloid (mg/kg dry wt.)
Arsenic (As)	12	42
Organic-PAHs (μg/kg dry wt.)
Low Molecular Weight PAHs High Molecular Weight PAHs	550 1700	3160 9600
Organic-non-PAHs (μg/kg dry wt.)
Total PCBs	23	180
Organometallics (μg TBT/l in Interstitial water)
Tributyltin*	0.15	0.15

* Contaminant level is considered to exceed UCEL if it is greater than the value shown.

11.2.1.14 Based on these criteria, the sediment is classified into Category L (low contamination level), Category M (medium contamination level) or Category H (high contamination level).

· Category L: Sediment with all contaminant levels not exceeding the LCEL. The material must be dredged, transported and disposed of in a manner which minimises the loss of contaminants either into solution or by resuspension.

· Category M: Sediment with any one or more contaminant levels exceeding the LCEL and none exceeding the UCEL. The material must be dredged and transported with care, and must be effectively isolated from the environment upon the final disposal unless appropriate biological tests demonstrate that the material will not adversely affect the marine environment.

· Category H: Sediment with any one or more contaminant levels exceeding the UCEL. The material must be dredged and transported with great care, and must be effectively isolated from the environment upon the final disposal.

11.2.1.15 The ETWB TCW No.34/2002, also, stipulates a three-tiered screening for sediment assessment for determining the disposal options. The detailed description of the 3-tier approach is described as follows:

· Tier I screening is a desktop screening process to review the available information and determine whether the sediment of concern belongs to Category L material suitable for open sea disposal. If there is insufficient information to arrive at such conclusion, Tier II chemical screening shall proceed directly.

· Tier II screening is a chemical screening process to categorise sediment based on its chemical contaminant levels and to determine whether the sediment is suitable for open sea disposal without further testing. Upon Type II screening, the sediment shall be classified as Category L, M or H material. There are three types of disposal options: Types 1, 2 and 3 disposal represent open sea disposal, confined marine disposal and special treatment/disposal respectively. Category L material is suitable for open sea disposal, but Categories M and H will require Tier III screening to further determine the disposal option.

· Tier III screening is a biological screening process to identify the most appropriate disposal option for Category M (either Type 1 or 2) and certain Category H sediment (either Type 2 or 3). Sediment classified as Category M or Category H (> 10 x LCEL) shall be subjected to the following three toxicity tests: (i) 10-day burrowing amphipod toxicity test; (ii) 20-day burrowing polychaete toxicity test; and (iii) 48-96 hour larvae (bivalve or echinoderm) toxicity test.

11.2.1.16 The WBTC No. 12/2000 defines the responsibilities of the MFC and PFC. It also sets out the terms of reference and membership of the two committees and provides explanation on the management of fill resources, construction and demolition material, and dredged/excavated sediment disposal.

Lands (Miscellaneous Provisions) Ordinance (Cap 28)

11.2.1.17 The inert portion of C&D materials may be taken to public filling facilities including public filling areas, public filling barging points and stockpiling areas. These facilities usually form part of the land reclamation schemes and are operated by the Civil Engineering and Development Department (CEDD). This Ordinance requires Dumping Licenses (to be issued by the CEDD) to be obtained by individuals or companies, who deliver inert C&D materials to the public filling facilities.

11.2.1.18 Individual licenses and windscreen stickers are issued for each vehicle involved. Public filling areas will accept only inert building debris, soil, rock and broken concrete. There is no size limitation on the rock and broken concrete, and a small amount of timber mixed with inert material is permissible. The material should, however, be free from marine mud, household refuse, plastic, metal, individual and chemical wastes, animal and vegetable matters and any other materials considered unsuitable by the Filling Supervisor.

Public Cleansing and Prevention of Nuisances Regulation

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

Other Relevant Guidelines on Waste Management

11.2.1.20 The following guidelines also relate to the waste management and disposal:

· Technical Memorandum on Environmental Impact Assessment Process (TM-EIAO), Annex 15 – Guidelines for Assessment of Waste Management Implications, and Annex 7 – Criteria for Evaluating Waste Management Implications;

· Waste Reduction Framework Plan, 1998-2007, Planning Environment and Lands Branch, Government Secretariat (1998);

· Waste Disposal Plan for Hong Kong (1989);

· Hong Kong Planning Standards and Guidelines (HKPSG), Chapter 9 – Environment;

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

· New Disposal Arrangement for Construction Waste (1992), Environmental Protection Department & Civil Engineering Department;

· 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 Sub-committee Papers;

· WBTC No. 12/2000, Fill Management, Hong Kong SAR Government;

· WBTC Nos. 6/2002 and 6/2002A, Enhanced Specification for Site Cleanliness and Tidiness. Works Bureau, Hong Kong SAR Government;

· WBTC No. 12/2002, Specification Facilitating the Use of Recycled Aggregates. Works Bureau, Hong Kong SAR Government;

· ETWB TC(W) No. 33/2002 Management of Construction and Demolition Material Including Rock;

· ETWB TC(W) No. 34/2002 Management of Dredged/ Excavated Sediment;

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

· DevB TC(W) No. 6/2010 Trip Ticket System for Disposal of Construction and Demolition Materials, Development Bureau, Hong Kong SAR Government;

· Practice Note for Professional Persons – Construction Site Drainage (ProPECC PN 1/94), Professional Persons Consultative Committee (1994).

11.2.1.21 According to ETWB TC(W) No. 33/2002, for Designated Projects, a Construction and Demolition Material Management Plan (C&DMMP) should be submitted, together with the Environmental Impact Assessment (EIA) Report to the PFC for approval in case C&D materials exceed 50,000m³. Appendix 11D contains the Construction and Demolition Material Management Plan for Trunk Road T2 and Infrastructure at South Apron.

11.2.1.22 The ETWB TC(W) No. 19/2005 also sets out the policy and procedures requiring contractors to prepare and implement an environmental management plan to encourage on-site sorting of C&D materials and to reduce C&D waste generation during construction.

11.2.1.23 According to the DevB TC(W) No.6/2010 Trip Ticket System for Disposal of Construction and Demolition Materials, all contracts that are expected to generate inert C&D materials (e.g. soil, broken rock, broken concrete and building debris, etc) requiring disposal from the site, the project office shall write to the PFC to request for a designated disposal ground for incorporation into the tender documents. For contracts where the estimated amount of non-inert C&D materials requiring disposal at landfill facilities equal or exceed 50m3, the project office shall seek confirmation from the EPD in terms of the availability of landfill facilities for disposal of such materials. The EPD will designate landfill facilities, if available, for the contract. Where the estimated amount of non-inert C&D materials to be generated from the contract is less than 50m3, the project office is not required to apply to the EPD for designated landfill facilities. However, the project office should specify in the tender documents of the appropriate landfill facilities for disposal.

11.2.1.24 ETWB TC(W) No. 34/2002 stipulates the procedures for seeking approval to dredged sediment and the management framework for marine disposal of such sediment. Applications for approval of dredging proposals and allocations of marine disposal shall be made to the Secretary of MFC. Marine Dumping Permits as stipulated under the DASO are required from the EPD for the disposal of dredged sediment. Details of the assessment methodology have been provided above.

11.2.2 Land Contamination

11.2.2.1 The following legislation is relevant to the land contamination issues as a result of handling, treatment and disposal of contaminated materials:

· Environmental Impact Assessment Ordinance (Cap 499);

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

· Dangerous Goods Ordinance (CAP 295).

11.2.2.2 The following EPD publications provide guidance on the land contamination assessment for this EIA:

· 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.

11.3 Assessment Methodology

11.3.1 Waste Management

11.3.1.1 The assessment of the waste management implications as a result of the Trunk road T2 project has been undertaken based on the project description in Section 3 of this EIA report. The assessment of the environmental impacts from the handling, storage, collection, transportation and disposal of waste material generated by the project has been undertaken in accordance with Annex 7 and Annex 15 of the TM-EIAO.

11.3.1.2 The waste management hierarchy has been applied in the assessment and development of mitigation measures for waste undertaken as required. The waste management hierarchy is a concept which shows the desirability of various waste management methods and comprises the following in order of preference:

· avoidance;

· minimisation;

· recycling/reuse;

· treatment; and

· disposal.

11.3.1.3 All opportunities for reducing waste generation have been assessed based upon the following factors:

· avoiding or minimising waste generation through changes in the design;

· adopting better management practices to promote segregation of waste materials;

· reuse and recycling; and

· diverting waste to public dumps or other construction sites.

11.3.1.4 The types and quantities of waste have been estimated and disposal options for each category of waste identified, taking into account the existing or future spare capacities of the waste disposal facilities and the environmental implications of the handling, collection and disposal of waste material. The potential environmental impacts associated with the handling, transportation and disposal of waste arising from the construction works will be assessed with reference to the following approach:

· estimation of the types, timing and quantities of the wastes to be generated and fill to be imported; and

· assessment of the potential environmental impacts on the capacity of waste collection, transfer and disposal facilities.

11.3.1.5 The impacts caused by handling (including stockpiling, labelling, packaging and storage), collection, transportation and re-use/disposal of wastes have been addressed in detail and appropriate mitigation measures have been proposed. This assessment covers the potential hazard, air and odour emissions, noise, wastewater discharge and public transport.

11.3.2 Contaminated Land

11.3.2.1 The land contamination assessment at the concerned previously developed land lot currently occupied by PCCW and a short section of Cheung Yip Street, as shown in Figure 11.2b has been carried out with reference to the EPD’s Practice Guide for Investigation and Remediation of Contaminated Land. The sequence of steps involved in the assessment process is summarised below:

· Carrying out the site appraisal (information collection);

· Designing site investigation and preparing the CAP for EPD’s approval;

· Conducting the site investigation;

· Interpreting results and preparing the CAR for EPD’s approval;

· Planning and designing the remediation works and preparing the Remediation Assessment Plan (RAP) for EPD’s approval;

· Carrying out the remediation works; and

· Preparing the Remediation Report (RR) for EPD’s endorsement.

11.3.2.2 The assessment for land contamination is based on details of the planned construction works as described in Section 3 of this EIA report. The works for the cut and cover tunnel sections to be conducted at the concerned land lot would, also, comprise the construction of access shafts where excavated Construction and Demolition (C&D) materials would be generated.

11.3.2.3 Details of the field sampling and laboratory analyses in the SI undertaken in June to August 2012 have been provided in the endorsed CAP (Appendix 11B). The soil bore and trial pit logs with the description of sub-soil strata were prepared and all sampling equipment and apparatus were thoroughly cleaned and decontaminated before and after drilling and sampling at each sampling location. All necessary measures were provided to comply with the requirements in respect of environmental, health and safety aspects.

11.3.2.4 The results of the laboratory analyses were interpreted in accordance with the Guidance Note for Contaminated Land Assessment and Remediation, and Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management. Reference was made to the RBRG criteria for assessing the degree of land contamination in the site based on the proposed future land use as tabulated in Tables 11.2 and 11.3 below. The future land use of the study area for the trunk road inside the cut-and-cover tunnel with transport operation was classified as “Industrial”. Also, with reference to the Outline Zoning Plan No. S/K22/2: Kowloon Planning Area No. 22 Kai Tak, the future land uses above the trunk road cut-and-cover tunnel would be “Open Space” and “Other Specified Use”, so they were classified as “Public Park” for this contamination assessment. It would be based on these classifications that the land contamination assessment (and remediation if required) was carried out.

Table 11.2 Risk-Based Remediation Goals for Soil and Soil Saturation Limit

Chemical		Risk-Based Remediation Goals for Soil		Soil Saturation Limit (Csat) (mg/kg)
		Industrial (mg/kg)	Public Parks (mg/kg)
VOCs
Benzene		9.21E+00	4.22E+01	3.36E+02
Ethylbenzene		8.24E+03	1.00E+04*	1.38E+02
Toluene		1.00E+04*	1.00E+04*	2.35E+02
Xylenes (Total)		1.23E+03	1.00E+04*	1.50E+02
SVOCs
Acenaphthene		1.00E+04*	1.00E+04*	6.02E+01
Acenaphthylene		1.00E+04*	1.00E+04*	1.98E+01
Anthracene		1.00E+04*	1.00E+04*	2.56E+00
Benzo(a)anthracene		9.18E+01	3.83E+01	-
Benzo(a)pyrene		9.18E+00	3.83E+00	-
Benzo(b)fluoranthene		1.78E+01	2.04E+01	-
Benzo(g,h,i)perylene		1.00E+04*	5.74E+03	-
Benzo(k)fluoranthene		9.18E+02	3.83E+02	-
Chrysene		1.14E+03	1.54E+03	-
Dibenzo(a,h)anthracene		9.18E+00	3.83E+00	-
Fluoranthene		1.00E+04*	7.62E+03	-
Fluorene		1.00E+04*	7.45E+03	5.47E+01
Indeno(1,2,3-cd)pyrene		9.18E+01	3.83E+01	-
Naphthalene		4.53E+02	9.14E+02	1.25E+02
Phenanthrene		1.00E+04*	1.00E+04*	2.80E+01
Pyrene		1.00E+04*	5.72E+03	-
Metals
Antimony	2.61E+02		9.79E+01	-
Arsenic	1.96E+02		7.35E+01	-
Barium	1.00E+04*		1.00E+04*	-
Cadmium	6.53E+02		2.45E+02	-
Chromium III	1.00E+04*		1.00E+04*	-
Chromium VI	1.96E+03		7.35E+02	-
Cobalt	1.00E+04*		4.90E+03	-
Copper	1.00E+04*		9.79E+03	-
Lead	2.29E+03		8.57E+02	-
Manganese	1.00E+04*		1.00E+04*	-
Mercury	3.84E+01		4.56E+01	-
Molybdenum	3.26E+03		1.22E+03	-
Nickel	1.00E+04*		4.90E+03	-
Tin	1.00E+04*		1.00E+04*	-
Zinc	1.00E+04*		1.00E+04*	-
Dioxins/PCBs
PCBs	7.48E-01		7.56E-01	-
Petroleum Carbon Ranges
C6 - C8	1.00E+04*		1.00E+04*	1.00E+03
C9 - C16	1.00E+04*		1.00E+04*	3.00E+03
C17 - C35	1.00E+04*		1.00E+04*	5.00E+03

Note: Soil saturation limits for petroleum carbon ranges taken from the Canada-Wide Standards for Petroleum Hydrocarbons in Soil, CCME 2000. * denotes a ‘ceiling limit’ concentration.

Table 11.3 Risk-Based Remediation Goals for Groundwater and Solubility Limit

Chemical	Risk-Based Remediation Goals for Groundwater	Solubility Limit (mg/L)
	Industrial (mg/L)
VOCs
Benzene	5.40E+01	1.75E+03
Ethylbenzene	1.00E+04*	1.69E+02
Toluene	1.00E+04*	5.26E+02
Xylenes (Total)	1.57E+03	1.75E+02
SVOCs
Acenaphthene	1.00E+04*	4.24E+00
Acenaphthylene	1.00E+04*	3.93E+00
Anthracene	1.00E+04*	4.34E-02
Benzo(a)anthracene	-	-
Benzo(a)pyrene	-	-
Benzo(b)fluoranthene	7.53E+00	1.50E-03
Benzo(g,h,i)perylene	-	-
Benzo(k)fluoranthene	-	-
Chrysene	8.12E+02	1.60E-03
Dibenzo(a,h)anthracene	-	-
Fluoranthene	1.00E+04*	2.06E-01
Fluorene	1.00E+04*	1.98E+00
Indeno(1,2,3-cd)pyrene	-	-
Naphthalene	8.62E+02	3.10E+01
Phenanthrene	1.00E+04*	1.00E+00
Pyrene	1.00E+04*	1.35E-01
Metals
Antimony	-	-
Arsenic	-	-
Barium	-	-
Cadmium	-	-
Chromium III	-	-
Chromium VI	-	-
Cobalt	-	-
Copper	-	-
Lead	-	-
Manganese	-	-
Mercury	6.79E+00	-
Molybdenum	-	-
Nickel	-	-
Tin	-	-
Zinc	-	-
Dioxins/PCBs
PCBs	5.11E+00	3.10E-02
Petroleum Carbon Ranges
C6 - C8	1.15E+03	5.23E+00
C9 - C16	9.98E+03	2.80E+00
C17 - C35	1.78E+02	2.80E+00

Notes: “-“ denotes that RBRG could not be calculated because the toxicity or physical/chemical values were unavailable, or the condition of Henry’s Law Constant>1.00E-05 was not met for the inhalation pathway; Water solubilities for Petroleum Carbon Range aliphatic C9-C16 and greater than C16 generally are considered to be effectively zero and therefore the aromatic solubility for C9-C16 is used; * denotes a ‘ceiling limit’ concentration.

11.4 Construction Phase Waste Management Assessment

11.4.1 Wastes Types

11.4.1.1 The construction of Trunk Road T2 will involve a number of activities which will generate waste that can be broadly be classified into distinct categories based on its nature and the options for disposal. These include:

· Excavated marine deposit (sediment) buried underneath the South Apron and Cha Kwo Ling works areas for the construction of cut-and-cover tunnel sections;

· Excavated C&D materials suitable for public fill, including the alluvium from the subsea tunnel construction;

· C&D waste which is not suitable for public fill;

· Chemical waste;

· Sewage; and

· General refuse.

11.4.1.2 It should be noted that as the subsea tunnel will be constructed using the Tunnel Boring Machine (TBM) method, as detailed in Section 3, no marine dredging is required and as a result, no marine sediment will be extracted from the marine waters. As such, the marine deposits to be generated by the Trunk Road T2 project will be restricted to the sediment located under the reclaimed land to be excavated during the land-based works at the South Apron and Cha Kwo Ling.

11.4.1.3 In accordance with the ETWB TC(W) No.33/2002, a C&DMMP has been prepared. The preliminary quantities and nature of the waste predicted to be generated by the Trunk Road T2 project have been estimated in the C&DMMP, which has been submitted to the PFC with endorsement in principle by the CEDD’s Vetting Committee on 28 February 2013 (letter as included in Appendix 11C). The quantities provided have been estimated based on the current preliminary design which has established the principal dimensions of the Trunk Road T2 works. The key dimensions for the establishment of the waste materials, such as of the length of cut and cover tunnel, TBM tunnel, depth of the works, are fixed by the site constraints and engineering feasibility and are not anticipated to be subject to change. Bulking factors have been applied to the excavated materials and an additional expansion factor has been allowed for in the quantities of treated marine deposits to allow for the mixing of the marine deposits with sand and cement. The extent and proportions of the excavated materials has been established from the project specific Stage I Ground Investigation.

11.4.1.4 These dimensions and quantities are considered to be within reasonable accuracy based upon this preliminary stage of the design. Refinement of the design will take place in the detailed design stage along with a further Stage II ground investigation to provide more accurate definition of the extent and type of each material along the tunnel section. However, it is not anticipated that such refinement would result in a significant change in the quantities in this EIA. The programming of the works has assumed construction rates to result in a conservative estimate on the export of material off site and a conservative use of the site stockpile areas. These can be adjusted to suit the actual conditions and progress on site without adversely impacting the assumptions of this EIA.

11.4.2 Excavated Marine Sediment

11.4.2.1 The disposal of sediment in Hong Kong waters is controlled under the DASO. It should be noted that in accordance with the DASO, the requirements as stipulated in the ETWB TC(W) No.34/2002 should be strictly followed prior to the dredging and disposal of sediment.

11.4.2.2 The sampling and testing of the marine sediment was carried out during site investigation works for the Trunk Road T2 project in September to November 2010, including the marine deposit buried underneath the South Apron and Cha Kwo Ling works areas, using a general sampling grid of 200m with vertical profiling down to the anticipated excavation level, according to the sediment testing and sampling plan, as endorsed by the EPD, shown in Appendix 11A.

11.4.2.3 Detailed fieldwork records and laboratory test results for the marine deposit buried underneath the South Apron works area are, also, included in Appendix 11A. These provide quantitative information for a preliminary estimation of the quantities of contaminated and uncontaminated buried marine deposit likely to be excavated from the Trunk Road T2 project. It should be noted that sampling and testing were not carried out at some borehole locations e.g. L113BH, as they fell under the extent of the alignment option that was not selected as the preliminary design of Trunk Road T2 described in Section 3 of this EIA Report. Also, the proposal for an additional L119BH was to suit the most updated preliminary design for the selected option of Trunk Road T2 as described in Section 3 of this EIA Report, and all the sampling and testing requirements were based on the proposed approach in the endorsed "Marine Sediment Sampling Proposal".

11.4.2.4 A total of nine (9) sub-samples of buried marine deposit at four (4) borehole locations, namely L102BH, L106BH, L110BH and L119BH, were collected (Figure 11.1) within the project boundary for the Trunk Road T2 at the South Apron. The marine deposit layer was found to span between 12.0m and 15.5m below ground level. With reference to the chemical tests under the ETWB TCW No.34/2002, the test results as summarised in Table 11.4 and included in Appendix 11A for all samples exhibited compliance with the LCELs and they were, therefore, classified as Category L. No biological screening for these samples was conducted. Therefore, there were no samples of sediment exhibiting exceedances of the LCELs and/or the UCELs.

11.4.2.5 At the Cha Kwo Ling end of the Trunk Road T2 project, within the project boundary, one borehole was constructed at this location, borehole 115BH (Figure 11.1b). However, no marine deposit was identified as shown in the fieldwork records in Appendix 11A and, therefore, the estimation of the total quantity of the excavated marine deposit in the Trunk Road T2 project has not included this works area. However, previous site investigation borehole records from 1991 in the vicinity of the Trunk Road T2 works area in Cha Kwo Ling have showed a marine deposit layer as illustrated in Figure 11.1b. As there would be a possibility of the Trunk Road T2 excavation works encountering buried marine deposit in this area, the subsequent management of any marine deposit arising would be confirmed by additional site investigations. If marine sediment is encountered in the future excavation works in this works area, ETWB TC(W) No. 34/2002 would be followed to ensure the proper handling and disposal of the marine sediment.

11.4.2.6 Based on the findings of the 2010 site investigations and the preliminary sediment testing results, the total estimated quantity of the excavated marine deposit anticipated to arise from the cut and cover excavation works on the South Apron during the entire construction period of the Trunk Road T2 project would be approximately 81,030m³ of Cat L material. The marine deposit is proposed to be treated on site and the treated backfill marine deposits will consist of 70% marine mud and 20% granular material/marine sand, plus 10% cement. The ultimate quantity of the treated backfill marine deposits will be 145,415 m³, derived as follows:

81,030m³ x (7+2+1)/7 x 1.142 x 1.1 = 145,415 m³

where:

- 1.142 is the post-mixing expansion factor, and

- 1.1 is the bulk factor.

Table 11.4 Sediment Quality and Classification

Parameters		Ag	As	Cd	Cr	Cu	Ni	Pb	Zn	Hg	PCBs	Low Mr Wt PAHs	High Mr Wt PAHs	Tributyltin – Soluble	Sediment Classification
Unit (In dry Wt basis)		mg/ kg	mg/ kg	mg/ kg	mg/ kg	mg/ kg	mg/kg	mg/kg	mg/kg	mg/kg	mg /kg	mg/kg	mg/kg	mg TBT/L
Reporting Limits		0.1	1	0.2	1	1	1	1	1	0.05	18	550	1700	0.015
LCEL		1	12	1.5	80	65	40	75	200	0.5	23	550	1700	0.15
UCEL		2	42	4	160	110	40	110	270	1	180	3160	9600	0.15
Sample Description*
Sample ID	Depth (m)
L102BH	13.4 to 14.3	<0.1	5	<0.2	21	6	14	19	100	<0.05	<18	<550	<1700	IS	L
L102BH	14.3 to 15.3	<0.1	6	<0.2	24	6	15	16	69	<0.05	<18	<550	<1700	IS	L
L102BH	15.3 to 15.5	<0.1	5	<0.2	20	6	13	15	102	<0.05	<18	<550	<1700	IS	L
L106BH	14.0 to 14.9	<0.1	6	<0.2	24	6	13	18	49	<0.05	<18	<550	<1700	IS	L
L106BH	14.9 to 15.2	<0.1	6	<0.2	26	10	15	18	155	<0.05	<18	<550	<1700	IS	L
L110BH	12.0 to 12.9	<0.1	5	<0.2	21	7	14	15	70	<0.05	<18	<550	<1700	IS	L
L110BH	12.9 to 13.9	<0.1	5	<0.2	20	12	14	19	83	<0.05	<18	<550	<1700	IS	L
L119BH	13.5 to 14.4	<0.1	4	<0.2	19	5	12	14	49	<0.05	<18	<550	<1700	IS	L
L119BH	14.5 to 15.0	<0.1	5	<0.2	21	6	12	15	60	<0.05	<18	<550	<1700	IS	L

Notes: IS = Insufficient sample for analysis; All values in dry weight; * Details of field sampling and laboratory analysis are provided in Appendix 11A.

11.4.2.7 The excavated marine deposits would be transported to the stockpile area in Works Area WA4 for treatment as soon as practicable after the material has been excavated. Conversion of soft marine mud into a material suitable for earth filling would be in batches and via a cement-stabilisation process that is aimed at improving the marine mud to a state comparable to that of the compacted general fill, that is, either medium dense granular soils or stiff cohesive soils and uncontaminated. The cement stabilisation process not only improves the structural stability and properties of the mud but would, also, bind any contamination such that it would not be leached out in future when reused. The cement-stabilisation process would involve mixing the marine deposits with a granular material and Portland cement in a mixer. It is anticipated that the excavation rate may reach a maximum daily production rate of about 1000m³ with the treatment process anticipated to reach a maximum daily production of 350m³. For those quantities of excavated marine deposit not immediately processed, they would be stockpiled on site at WA4 for an anticipated 2 weeks prior to treatment. The processed materials would also be stockpiled at WA4 until required for backfilling on to the completed section of cut and cover tunnel. The period of stockpiling of the treated excavated materials is estimated to be approximately 8 months based on the tentative programme given in Appendix 3A.

11.4.2.8 It is currently envisaged that 100% of the treated marine deposits (145,415m³) will be reused for backfilling on site such that no surplus treated marine deposits will need to be disposed at the fill bank. While agreement in principle has been obtained from the CEDD’s Vetting Committee on 28 February 2013 (letter as included in Appendix 11C), and the C&DMMP was submitted to the PFC for endorsement on 9 May 2013, agreement from relevant parties (e.g. MFC, PFC, and Water Policy and Science Group of EPD, etc) will be sought for the above proposal as appropriate.

11.4.2.9 Otherwise, ETWB TC(W) No.34/2002 will be followed for the proper handling and disposal of the sediments accordingly. According to the ETWB TC(W) No. 34/2002 which stipulates the procedures for seeking approval to the management framework for marine disposal of such sediment, application for the approval of allocations of marine disposal would be made to the Secretary of MFC. Marine Dumping Permits as stipulated under the DASO are required from the EPD for the disposal of dredged sediment and the requirements as stipulated in the ETWB TC(W) No.34/2002 would be strictly followed. The Sediment Quality Report will be prepared in due course, in accordance with ETWB TC(W) No. 34/2002. While the Category L marine deposit has been shown to be overall uncontaminated in nature, the dredging operations, handling and disposal of the sediment may cause impacts to the marine environment and ecology if proper management measures are not implemented. It is proposed to dispose of all these Category L in a Type I Open Sea Disposal site in Hong Kong, e.g. at South of Cheung Chau, East of Ninepins, subject to DASO application. With proper preventive and mitigation measures in place for handling, transport and disposal as per the requirements given in the ETWB(W) No.34/2002, no insurmountable environmental impacts would be anticipated. Excavation work would not proceed until all issues on management of dredged/excavated sediments have been resolved and all relevant arrangements have been endorsed by the relevant authorities including the MFC, PFC and EPD.

11.4.2.10 In order to minimise any potential adverse impacts arising from the handling, treatment and disposal of the buried marine deposit, it should be excavated, transported and processed properly. With suitable dust suppression measures, it is expected that the excavation of buried marine deposit would not cause significant adverse dust impacts on nearby air sensitive receivers. Also, with the uncontaminated nature and low organic matter content of the buried marine deposit in the South Apron works area, as detailed in the geotechnical testing results in the fieldwork report in Appendix 11A, in addition, the use of tarpaulins or similar to cover the material both before and after treatment, it is expected that potential odour emissions from the excavated and stockpiled marine deposit would be minimal and adverse odour impacts would not be anticipated. It should, also, be noted that once treated, no odour at all would be expected from the sediment. With all relevant noise mitigation measures in place, including a noise barrier around the stockpiling area, adverse noise impact would not be expected during the course of the excavation and treatment process of the buried marine deposit.

11.4.3 Construction and Demolition Materials

Background

11.4.3.1 C&D materials to be generated during construction will comprise materials that are suitable for reuse on site or as public fill and a portion of waste material that will require disposal to a licensed landfill facility. For the purposes of this assessment, these two fractions are denoted C&D material and C&D waste and are discussed in the sections below.

11.4.3.2 The C&D materials generated from Trunk Road T2 project will comprise the following:

· Concrete from site clearance and road and pavement demolition, given that much of the areas is already developed and covered in hard-standing;

· General fill and sand fill from site clearance and excavation and construction works for the at-grade and depressed road sections, cut and cover tunnel works, ventilation buildings and TBM launching and receiving shafts; and

· Alluvium and Grade II rock, largely from the subsea tunnel construction by TBM.

11.4.3.3 In addition to the C&D materials that would be generated, as noted above, which are suitable for reuse on site or as public fill, some C&D waste would, also, be generated during the construction phase. These materials include:

· Any cleared vegetation;

· Wood from formwork;

· Unusable cement mixes; and

· Damaged or contaminated construction materials.

C&D Materials Generated

11.4.3.4 In accordance with the waste hierarchy presented above, it is necessary to consider all ways to avoid the generation of C&D materials and also reuse within the Trunk Road T2 Project. The following methods have been planned for implementation:

Minimising Generation of C&D Materials

· Cut and Fill Balance: Efforts have been given to minimise excavation and balanced cut and fill requirements;

· Contract Provision: There would be adequate provisions in the contract specifications regarding the minimisation of the generation of C&D material, enhancement of the reuse and recycle of C&D material, and the control on the disposal of C&D material and waste; and

· Optimisation of the tunnel profile: the tunnel profile has been minimised whilst maintaining adequate space for the structural gauge, ventilation spatial requirement and permanent support envelope. In addition, the shortest alignment has been selected to minimise C&D material generation.

Maximising Use of C&D Materials

· Site formation works are needed in the South Apron for the at-grade roads and ventilation building and inert C&D materials from the project are proposed to be reused at this location. The excavated materials from earthworks would be reused as much as possible to minimise the amount of materials to be disposed off site;

· During construction, the formwork would be designed to maximise the use of standard panels so that a high level of reuse could be achieved. More durable alternatives such as steel formwork or plastic facing would be considered for repetitive pours/panels to increase the potential for reuse; and.

· The procedure for handling the C&D materials will be separated into reusable items and materials to be “disposed of” or “recycled”. It would be conducted at the immediate working area, if practicable, to avoid loss or leakage during handling. All C&D materials arising from or in connection with the construction and demolition work would be sorted on-site and be separated into different categories for disposal at landfills, public filling reception facilities (when surplus is generated), or reuse and recycling as appropriate. Useful materials such as timber, rubble and steel/metal would be segregated for reuse, e.g. formwork and timber to be cleaned for reuse, off-cuts of reinforcement to be sorted into usable lengths and short off-cuts stacked for scrap. Where it is no longer reusable, steel and metal items would be sent as scrap for recycling. Re-usable metal hoardings and signboards should, also, be utilised on site to reduce the volumes of inert C&D materials.

11.4.3.5 A summary of the C&D materials anticipated to arise from the Trunk Road T2 project is given in Table 11.5. Table 11.6, also, shows a summary of surplus C&D materials arising from this Project and the tentative programme for their disposal.

Table 11.5 Summary of C&D Materials Arising from the Project

C&D Material Type	Estimated Volume (m^3)			Origin	Potential Area of Reuse or Disposal
	Excavated	Reuse	Surplus
Broken Concrete	11,846	0	11,846	Surface site clearance works for the at-grade works, depressed road section, cut and cover tunnel sections, launching and receiving shafts.	Off-site disposal.
Alluvium	445,965	134,899	311,066	Excavation for cut and cover tunnel sections, TBM launching and receiving shafts, TBM subsea tunnel.	Backfilling of cut and cover tunnels. Off-site disposal of surplus.
Soft Material – Sand Fill	310,933	39,709	271,224	Excavation works for cut and cover tunnel sections, depressed road, TBM launching and receiving shafts, and excavation from construction of ventilation buildings for ground preparation works.	Backfilling of cut and cover tunnels. Off-site disposal of surplus.
Excavated Material – Grade III or below Rock	397,804	56,834	340,970	Excavation works for cut and cover tunnel sections, TBM launching and receiving shafts, and TBM subsea tunnel.	Backfilling of cut and cover tunnels. Off-site disposal of surplus.
Excavated Material – Grade II or above Rock	40,874	0	40,874	Excavation works for TBM receiving shafts, and TBM subsea tunnel.	Off-site disposal.
TOTAL	1,207,422	231,442	975,980

Note: Excludes quantities generated by other contracts but stockpiled on Trunk Road T2 works areas and to be removed form site by Trunk Road T2

Table 11.6 Summary of Surplus C&D Materials and Time of Arising for Disposal

C&D Material Type	Estimated Surplus Volume (m^3) and Time of Arising
	2015	2016	2017	2018	2019	Total
Broken Concrete	0	3,175	1,792	6,455	424	11,846
Alluvium	0	31,169	51,306	228,591	0	311,066
Soft Material – Sand Fill	0	21,077	30,348	219,163	636	271,224
Excavated Material – Grade III or below Rock	0	30,167	43,439	266,452	912	340,970
Excavated Material – Grade II or above Rock	0	0	2,920	37,954	0	40,874
Annual Total:	0	85,588	129,805	758,615	1,972	975,980

11.4.3.6 As noted above, the majority of the soft C&D material, comprising sand fill, Grade III rock and below and alluvium, makes up approximately 1.15Mm³, will be suitable for reuse or transfer to the public fill, in some cases, after treatment as required. The predicted surplus amount of this C&D material, in addition to the Grade II or above rock from the subsea tunnel, totally approximately 975,980m³, will be transferred to the Tseung Kwan O Area 137 Fill Bank and Chai Wan Public Fill Barging Point by barge. This principle of disposal for the surplus C&D material has been agreed with the PFC in January 2013. The endorsement in principle by the CEDD’s Vetting Committee on 28 February 2013 is included in Appendix 11C. Construction work should not proceed until all issues on management of C&D materials have been resolved and all relevant arrangements have been endorsed by the relevant authorities including PFC and EPD.

11.4.3.7 A description of the quantities and reuse of C&D materials for the various Trunk Road T2 construction activities are discussed below.

11.4.3.8 Site clearance will generate inert materials in the form of soil, rock and concrete, in addition to non-inert C&D waste materials such as timber, paper, vegetation and plastic. It will be important that cleared vegetation derived from the ground preparatory works should be segregated from any soil materials, where practical, and sent to a suitable disposal site identified and agreed by EPD. The landfills will generally only accept a maximum of 50% by weight of inert construction waste. It is, therefore, important that soil and vegetation are kept segregated. The inert and non-inert wastes would be classified clearly in the contract documents.

11.4.3.9 As the existing area within the Trunk Road T2 project boundary mainly consists of broken concrete, site clearance will likely comprise the 11,846m³ inert C&D materials which will not be reused on site as it will not be suitable for compaction over the tunnel structures and disposed off-site to the Tseung Kwan O Area 137 Fill Bank and Chai Wan Public Fill Barging Point. Site clearance will also generate general fill in the form of top soil. The top soil be removed during site clearance would contain a small amount of non-inert materials but would be reused and recycled as much as possible before disposal off site.

11.4.3.10 Under a previous contract (KL/2009/01) for the site formation for the Kai Tak Cruise Terminal Development a quantity of surplus rock material has been stored within the proposed Trunk Road T2 site area at the proposed works area WA4. The quantity of stockpiled surplus rock materials is 50,000m³. The materials are not generated by the Trunk Road T2 project and as such is not included in the quantities given in the Tables 11.5 and 11.6 above. The materials are, also, not suitable or required for the construction of the Trunk Road T2 and would be exported off site by the KL/2009/01 contract, prior to the start of the T2 contract, to provide space for the stockpile and fill treatment process on WA4.

11.4.3.11 The remaining general fill (comprising soft sand fill and Grade III or below rock) would be produced from the excavation works for the cut and cover tunnel sections, depressed road and the TBM launching and receiving shafts on the South Apron and Cha Kwo Ling Works Area 5 and TBM subsea tunnel, see Figures 11.1a and 11.1b. A total of 708,737m³ will be generated. General fill is, also, produced during the excavation works for the foundations for the ventilation buildings, generating 33,000m³.

11.4.3.12 Effort has been given to minimising the excavation for the cut and cover tunnel, depressed road, launching shaft, receiving shaft, and building construction and reuse of these excavated materials on site has been proposed as much as possible to minimise the amount of C&D materials for disposal off site.

11.4.3.13 It is proposed that the Contractor should programme the cut and cover tunnel construction works such that the excavated materials from the first cell of cut and cover works placed at the proposed nearby stockpiling area. The excavated materials from the second cell of cut and cover works could then be reused, if applicable, for backfilling to the first cell of cut and cover section. The excavated materials in the stockpiling area would then be reused as filling materials in the section of second cell of cut and cover works. This process continues and can minimise the surplus excavated materials for the disposed off site. Similarly the excavated materials from the depressed road, launching shaft, and receiving shaft would be placed at the proposed stockpiling area before reusing the excavated materials for the backfilling works on site.

11.4.3.14 In respect of the general fill, sand fill and Grade III rock, it is proposed to be reused on site in the backfilling for the cut and cover tunnel sections at the South Apron and CKL, respectively. No additional material can be used because there are no slope/embankment works requiring filling, no retaining walls requiring backfilling and the calculated re-use quantities already consider backfilling over the cut and cover tunnels up to the finished ground levels, leaving a surplus of 612,194m³ of general fill to be sent to the fill bank for reuse elsewhere.

11.4.3.15 Bentonite slurry will be used in the construction of the diaphragm walls used in the cut and cover tunnel sections on the South Apron and at Cha Kwo Ling before the Trunk Road T2 tunnel interfaces with the TKO-LTT project and for the TBM tunnelling process. Bentonite slurry is proposed to be reused as far as possible and the used bentonite slurry from the diaphragm walls and TBM will be collected and transferred to desander treatment plants, located within the site boundary, in a portion of the works not currently under construction and which will have construction works carried out later in the programme at the South Apron, see Figure 11.1a, for cleaning and subsequent recycling and reuse. The bentonite final residues would be disposed of in accordance with the Practice Notes For Professional Persons ProPECC PN 1/94. Slurry may either be disposed of at the marine disposal grounds (subject to the EPD’s approval) or to the public drainage system following the treatment to satisfy the relevant effluent discharge standards as set out in the Technical Memorandum on Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters (TM-DSS) requirements pursuant to the WPCO. The relevant permits / licences from the relevant authorities (e.g. DASO team for marine dumping licence, relevant regional office of EPD for WPCO licence) should be applied for prior to disposal.

11.4.3.16 As the excavation works for the Cha Kwo Ling receiving shaft is remote from the larger works and stockpile areas at the South Apron, it is envisaged that the excavated materials would be transported by road to the South Apron for stockpiling at WA4 or disposal from site via the barging point at WA2 over a period of about 4-5 months. The peak excavation at Cha Kwo Ling would be 18,000m³ a month and based upon a 24 days per month working, 10 hours per day, a maximum total of 90m³ per hour would be removed. Based upon an average truck capacity of about 7.5m³, a maximum of 12 trucks per hour would be required to transfer the material to the South Apron. The material would be transported via Cha Kwo Ling Road, Wai Yip Street, Hoi Bun road and Cheung Yip Street, all of which are already heavily utilised, with average flows of 300 to over 1000 vehicles per hour and they are generally surrounded by industrial buildings. As such, this additional traffic is not expected to cause any additional impacts to sensitive receivers along this route.

11.4.3.17 All the alluvium needs to be treated on site before it can either be reused or taken to the fill bank. The alluvium material will be treated at the Slurry Treatment Plant located in or adjacent to Works Area WA2 on the South Apron, see Figure 3.6, located as such because all the tunnel material will be removed via the launching shaft.

11.4.3.18 The purpose of the slurry treatment plant (STP) is to prepare, stock and control the slurry for recycling use. Produced from the TBM, the bentonite slurry with debris will be transported to the STP. The return slurry will be recycled in the slurry treatment plant. The plant uses vibrating screens/shakers to separate the coarser components (>4-6mm), uses one or more stages of “cyclones” to separate the fine components (>0.3-0.5mm), and uses special equipment such as “centrifuges”, press-belts and press-filters to separate the super-fines (>50μm). The remaining (<50μ) can be re-utilised together with the water, by adding to the fresh bentonite. In the Trunk road T2 case, two types of spoil, which is slurry mixed soil, are expected to be generated from the excavation in soft/mixed ground by the slurry TBM.  One is the ground with high sand/gravel content, the other is the ground with high silt/clay content.

11.4.3.19 When excavating in ground with high sand and gravel contents, the coarser sandy material, typically comprising 80% of the material, will come out from the de-sander units while the bentonite slurry, remaining 20%, is recycled to be re-used and pumped back to holding tanks. This type of spoil with high sand content tends to be relatively drier and can be disposed to public fill after the slurry treatment. When excavating in ground with high silt and clay contents, it is more difficult to completely separate the slurry from the silts and, as a result, the material is eventually disposed of, in a similar manner to bentonite, in accordance with the Practice Notes for Professional Persons ProPECC PN 1/94. Slurry may either be disposed of at the marine disposal grounds, subject to the EPD’s approval, or to the public drainage system following the treatment to satisfy the relevant effluent discharge standards as set out in the Technical Memorandum on Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters (TM-DSS) requirements pursuant to the WPCO.  The relevant permits / licences from the relevant authorities (e.g. DASO team for marine dumping licence, relevant regional office of EPD for WPCO licence) should be applied prior to disposal. The process will produce finer silty and clayey spoil material with a higher moisture content coming out from the centrifuges. Where required, the material shall be scarified to ensure it is "suitably" dried before it can be reused on site or disposed of to the fill bank.

11.4.3.20 The excess water would be treated to ensure compliance with the TM-DSS as discussed in Section 6 of this EIA report. While, no significant impacts associated with the C&D materials are predicted, waste management measures to control stockpiling, temporary storage and on-site transportation requirements, which could lead to short-term dust, visual and noise impacts, will be required. The construction works and the waste handling activities have been included in the construction air, noise, water quality and landscape and visual impact assessments and are considered to be minor and acceptable. The C&D materials will be carefully stockpiled if it cannot be reused or removed to avoid dust and other nuisance impacts.

11.4.3.21 A total of 134,899m³ of alluvium will be reused on site after treatment, leaving 311,066m³ to be removed to the fill bank at TKO Area 137. In addition, all the 40,874 m³ of Grade II or better rock produced by the subsea tunnel works will, also, be removed to the fill bank, with no reuse on site proposed as it is not suitable for backfilling on top of the cut and cover tunnels. The endorsement in principle by the CEDD’s Vetting Committee on 28 February 2013 is included in Appendix 11C. Construction work should not proceed until all issues on management of C&D materials have been resolved and all relevant arrangements have been endorsed by the relevant authorities including PFC and EPD.

Fill Materials Required

11.4.3.22 A total of 231,442m³ of generated material will be reused on site (Table 11.5) and this is considered sufficient to meet all backfill requirements for the Trunk Road T2 project. Therefore, it is not anticipated that any imported fill materials will be needed.

C&D Waste

11.4.3.23 The volume of C&D waste generated by the Project would depend on specific operating procedures and site practices. The use of steel falsework instead of wood has been a cost-effective practice in the industry and is assumed to be adopted here. As steel falsework is a proprietary system, it can be reused throughout the Trunk Road T2 project and subsequent projects. The use of steel would substantially reduce the amount of waste wood that the project generates. In addition, as the Trunk Road T2 project will be largely constructed in the marine environment or on already developed or previously reclaimed land with little vegetation, the amount of C&D waste generated from site clearance comprising a mixture of top soil and vegetative matter would be small and is expected to be approximately 2,000m³ of top soil, comprising both soil and vegetation. A summary of C&D waste anticipated to arise from the Trunk Road T2 project is given in Table 11.7.

Table 11.7 Summary of Surplus C&D Waste Generation and Time of Arising for Disposal

Activity	Material Type	Estimated Quantities of C&D Waste (m^3) and Time of Arising
		2015	2016	2017	2018	2019	Total
Earthworks	Top soil – soil/ vegetation	0	535	303	1,090	72	2,000

11.4.3.24 The other types of C&D waste are, also, expected to be limited, with only small quantities of maintenance and packaging waste being generated. Given that such materials would be generated in small quantities, significant impacts associated with its handling and disposal would not be expected.

11.4.3.25 Measures to minimise the generation of C&D waste should be implemented and demolition waste should be sorted to avoid contamination of other C&D materials suitable for public fill but significant impacts would not be predicted from the handling, storage or disposal of these materials.

11.4.4 Chemical Waste

11.4.4.1 Chemical wastes likely to arise from the construction activities for the Project would include:

· Scrap batteries or spent acid/alkali from maintenance activities;

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

· Spent mineral oils/cleansing fluids from mechanical machineries; and

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

11.4.4.2 Chemical wastes may pose environmental, health and safety hazards if not stored and disposed of appropriately as outlined in the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packing, Labelling 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 sewage treatment works should the chemical waste enter the sewerage system.

11.4.4.3 It is difficult to quantify the amount of chemical waste as it would be highly dependent on the future contractor’s on-site maintenance practices and the number of mechanical plant and vehicles utilised on-site. However, it is anticipated that the quantity of chemical waste arising, such as lubricating oil and solvent produced from plant maintenance would be relatively small (in the order of less than 500 litres per month), and if handled, stored, transported and disposed of in an appropriate manner, no adverse impacts would be predicted. Details of mitigation measures to protect against accidental spillages are provided in Section 6.

11.4.4.4 Notwithstanding, the future contractor should register to the EPD as a Chemical Waste Producer pursuant to the Waste Disposal (Chemical Waste) (General) Regulation and the chemical waste should be collected by licensed collectors for subsequent disposal at licensed waste disposal facilities, for example the Chemical Waste Treatment Centre in Tsing Yi.

11.4.5 Sewage

11.4.5.1 Sewage could arise from the amenity facilities used by the construction workforce and the site office’s sanitary facilities. Night soil from chemical toilets could, also, be generated. Sewage sludge will, therefore, need to be properly managed in order to avoid nuisance of odour and potential health risks to the workforce.

11.4.5.2 It is estimated that there will be a temporary workforce of about 500 people during the construction stage. While the toilets at the site offices will be connected to the local sewerage system which has sufficient capacity given the former airport or cargo operations on the sites, if necessary, chemical toilets will, also, be provided. However, based upon the chemical toilets being managed by a licenced Contractor, adverse waste impacts are not predicted.

11.4.6 General Refuse

11.4.6.1 The presence of construction sites with workers and site offices would generate a variety of general refuse which needs disposal, which would mainly consist of food waste, aluminium cans, waste paper, etc. Approximately 1000m³ of general refuse will be generated.

11.4.6.2 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. Construction sites may also attract pests, vermin and other disease vectors if the waste storage areas were not well maintained. Disposal of wastes at areas other than approved refuse transfer stations and landfills can also lead to similar adverse impacts.

11.4.6.3 The number of workforce (clerical and workers) to be employed for the Trunk Road T2 project construction is currently not available at this stage, but it is anticipated to be about 500 staff. On this basis, the total refuse generated per day would be about 0.55m³/day, assuming the refuse generated rate is 0.0011m³/head/day. Provided that mitigation measures are adopted, potential environmental impacts caused by the storage, handling, transport and disposal of general refuse would be expected to be insignificant. It is recommended that the general refuse should be collected on a daily basis and transferred to SENT Landfill. Given the relatively small quantities of general refuse expected, adverse impacts to the operation of the refuse transfer stations and landfills would not be expected.

11.4.7 Operational Phase Waste Management Assessment

11.4.7.1 The operational phase of the Trunk Road T2 project is not expected to generate any significant quantities of waste. The quantities of general refuse arising from the Project would be low and mainly arise from the plant maintenance workshops associated with the ventilation buildings. The quantities of chemical waste such as lubrication oils, used batteries, paints and solvents are likely to be generated but the quantities would be small and insignificant. Proper management procedures should be followed according to the EPD’s Code of Practice of the Packaging, Labelling and Storage of Chemical Waste. Standard good operating practice requirements should be followed in the storing, handling and transporting of any chemical wastes.

11.4.7.2 Operational sewage will be generated but, again, in small quantities as summarised in Table 3.2, based upon the staffing requirements for the ventilation buildings for the project. It should be noted that the administration building is combined with that of the Tseung Kwan O – Lam Tin Tunnel (TKO-LTT) project and is being constructed under that project, therefore, the assessment of impacts will be included in the TKO-LTT EIA report.

11.4.7.3 In both cases the amount of sewage generated will be very small. For the western ventilation building on the South Apron, the sewage from the facility is proposed to be discharged into the existing sewerage system. Adequate capacity in the local system to accommodate this amount is available. For the eastern ventilation building at Cha Kwo Ling, the sewage will need to be discharged to a sewage storage tank located adjacent to the facility as the building is located in an area which is much lower than the surrounding Cha Kwo Ling sewerage network and it is not considered practical to provide pumping arrangements for such small quantities.  The sewage in the tank will be managed by a licenced Contractor and would be emptied into a tanker before suitable disposal to the TKO-LTT sewage pumping station.

11.4.7.4 Based upon the above, no significant waste implications during the operational phase are predicted.

11.4.8 Waste Management Mitigation Measures

11.4.8.1 Mitigation measures are required to ensure the proper handling, storage, transportation and disposal of waste is carried out. Also measures to ensure that the generation of waste is avoided and minimised and that waste materials are recycled and treated as far as practicable. The recommended mitigation measures for all categories of waste are as follows.

(i) 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 future contractor as appropriate;

(ii) The future contractor should be requested to submit an outline Waste Management Plan (WMP) prior to the commencement of construction work, 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 include:

- Waste management policy;

- Record of generated waste;

- Waste reduction target;

- Waste reduction programme;

- Role and responsibility of waste management team;

- Benefit of waste management;

- Analysis of waste materials;

- Reuse, recycling and disposal plans;

- Transportation process of waste products; and

- Monitoring and action plan.

(iii) The waste management hierarchy should be strictly followed. This hierarchy should be adopted to evaluate the waste management options in order to maximise the extent of waste reduction and cost reduction. The records of quantities of waste generated, recycled and disposed (locations) should be properly documented;

(iv) A trip-ticket system should be established in accordance with DEVB TC(W) No. 6/2010 and Waste Disposal (Charges for Disposal of Construction Waste) Regulation to monitor the disposal of public fill and solid wastes at public filling facilities and landfills, and to control fly-tipping. A trip-ticket system would be included as one of the contractual requirements for the future contractor to strictly implement. The Engineer would also regularly audit the effectiveness of the system;

(v) A recording system for the amount of waste generated, recycled and disposed (locations) should be established. The future contractor should also provide proper training to workers regarding the appropriate concepts of site cleanliness and waste management procedures, e.g. waste reduction, reuse and recycling all the time;

(vi) The CEDD should be timely notified of the estimated spoil volumes to be generated and the PFC should be notified and agreement sort on the disposal of surplus inert C&D materials e.g. good quality rock during detailed design of the Trunk Road T2 Project. Wherever practicable, C&D materials should be segregated from other wastes to avoid contamination and to ensure acceptability at public filling areas or reclamation sites;

(vii) The extent of cutting operation should be optimised where possible. Earth retaining structures and bored pile walls should be proposed to minimise the extent of cutting;

(viii) Inert C&D materials from road pavement would be reused for backfilling where possible;

(ix) TBM generated alluvium and other C&D materials should be treated at a slurry treatment plant prior to transferring to Public Fill Reception Facilities;

(x) The site and surroundings should be kept tidy and litter free;

(xi) No waste is allowed to be burnt on site;

(xii) Make provisions in contract documents to allow and promote the use of recycled aggregates where appropriate;

(xiii) Prohibit the future contractor to dispose of C&D materials at any sensitive locations e.g. natural habitat, etc. The future contractor should propose the final disposal sites in the WMP for approval before implementation;

(xiv) Stockpiled C&D materials should be covered by tarpaulin and/or watered as appropriate to prevent windblown dust and surface run off;

(xv) Excavated C&D materials in trucks should be covered by tarpaulins to reduce the potential for spillage and dust generation;

(xvi) Wheel washing facilities should be used by all trucks leaving the site to prevent transferring mud trails onto public roads;

(xvii) Excavated marine deposit (sediment) should be disposed of in a gazetted marine disposal ground under the requirements of the DASO or treated for backfilling;

(xviii) Standard formwork or pre-fabrication should be used as far as practicable to minimise the C&D materials arising. The use of more durable formwork or plastic facing for construction works should also be considered. The use of wooden hoardings should be avoided and metal hoarding should be used to facilitate recycling. Purchasing of construction materials should be carefully planned in order to avoid over-ordering and wastage;

(xix) The future contractor should recycle as many C&D materials as possible on-site. The public fill and C&D waste should be segregated and stored in separate containers or skips to facilitate the reuse or recycling of materials and proper disposal. Where practicable, the concrete and masonry should be crushed and used as fill materials. Steel reinforcement bar should be collected for use by scrap steel mills. Different areas of the sites should be considered for segregation and storage activities;

(xx) All falsework should be steel instead of wood as far as practicable;

(xxi) Chemical waste producers should register with the EPD and chemical waste should be handled in accordance with the Code of Practice on the Packaging, Handling and Storage of Chemical Wastes as follows:

- suitable for the substance to be held, resistant to corrosion, maintained in good conditions and securely closed;

- Having a capacity of <450L unless the specifications have been approved by the EPD; and

- Displaying a label in English and Chinese according to the instructions prescribed in Schedule 2 of the Regulations.

- Clearly labelled and used solely for the storage of chemical wastes;

- Enclosed with at least 3 sides;

- Impermeable floor and bund with capacity to accommodate 110% of the volume of the largest container or 20% by volume of the chemical waste stored in the area, whichever is greatest;

- Adequate ventilation;

- Sufficiently covered to prevent rainfall entering (water collected within the bund must be tested and disposed of as chemical waste, if necessary); and

- Incompatible materials are adequately separated;

(xxii) Waste oils, chemicals or solvents should not be disposed of to drain;

(xxiii) Adequate numbers of portable toilets should be provided for on-site workers. Portable toilets should be maintained in reasonable states, which will not deter the workers from utilising them. Night soil should be regularly collected by licensed collectors;

(xxiv) General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes. Sufficient dustbins should be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws. In addition, general refuse should be cleared daily and disposed of to the nearest licensed landfill. Burning of refuse on construction sites is prohibited;

(xxv) All waste containers should be in a secure area on hardstanding;

(xxvi) Aluminium cans should be collected and recovered from the waste stream by reputable collectors if they are segregated and easily accessible. Separately labelled bins for their deposition should be provided as far as practicable;

(xxvii) 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 future contractor should be advocated. Waste separation facilities for paper, aluminium cans, plastic bottles, etc should be provided on-site; and

(xxviii) Training should be provided to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling.

11.4.8.2 Given that recommended mitigation measures are tried and tested techniques used extensively throughout Hong Kong construction projects, the level of uncertainty of their effective implementation would be small. Notwithstanding, the EM&A programme will be implemented to ensure all mitigation measures are effective.

11.4.9 Waste Disposal Recommendations

11.4.9.1 Based upon the estimated quantities and types of waste to be generated by the Trunk Road T2 Project, disposal options have been proposed, as detailed in Table 11.8 below.

Table 11.8 Recommended Waste Disposal Sites

Type of Waste	Disposal Site
Marine Deposit (Sediment) ^(1)	On-site backfilling after treatment
C&D materials	Tseung Kwan O Area 137 Fill Bank and Chai Wan Public Fill Barging Point
C&D waste (plastics, glass, wood, including cleared vegetation etc.)	SENT Landfill
Chemical waste (as defined under Schedule 1 of the Waste Disposal (Chemical Waste) Regulation)	Chemical Waste Treatment Centre in Tsing Yi or other approved facilities
General refuse	SENT Landfill

Note (1): Agreement from relevant parties (e.g. MFC, PFC and Water Policy and Science Group of EPD, etc) will be sought for the above proposal as appropriate. Otherwise, the ETWB TC(W) No.34/2002 will be followed for the proper handling and disposal of the sediments accordingly (refer to Section 11.4.2 above). Excavation work would not proceed until all issues on management of dredged/excavated sediments have been resolved and all relevant arrangements have been endorsed by the relevant authorities including the MFC, PFC and EPD.

11.4.10 Residual Impacts

11.4.10.1 The residual impacts refer to the net impacts after mitigation, taking into account the background environmental conditions and the impacts from existing, committed and planned projects. Residual impacts associated with the construction have been assessed but no quantification of residual impacts is required.

11.4.10.2 Assuming all the mitigation measures are implemented and the overall short term and temporary nature of the construction works, adverse residual impacts associated with the handling, storage, transportation or disposal of the waste generated by the project would not be anticipated and would not be expected to affect the health and welfare of the local community.

11.4.11 Environmental Monitoring and Audit

11.4.11.1 The assessment has concluded that the handling, transportation and disposal of waste materials during construction would not give rise to significant impacts if appropriate mitigation measures are implemented. However, it is recommended that during construction phase, regular site inspections and supervision of the waste management procedures shall be undertaken as part of the EM&A procedures, to ensure proper control, all waste is removed from site areas as appropriate and illegal disposal of waste is not being undertaken. Waste EM&A during the operational stage is not required. Further details of the specific construction phase EM&A requirements are detailed in Section 12 of this EIA Report and EM&A Manual.

11.5 Land Contamination Assessment

11.5.1 Background

11.5.1.1 Section 3 of this EIA Report provided the scope of the Trunk Road T2 Project and detailed descriptions of the associated works elements. A preliminary review of the historic land use and records together with reconnaissance site visits has been carried out, including the footprint of the preferred alignment, works sites and works areas, and ventilation and administration buildings, etc. A summary of the initial review is included in Appendix 11B which shows a preliminary appraisal of the Project and identified areas which would require further site investigation to warrant any potential of land contamination. This formed the basis of the development of the endorsed CAP (also included in Appendix 11B) for proceeding with site investigation of this land contamination assessment at Cheung Yip Street as shown in Figures11.2a and 11.2b.

11.5.1.2 It should be noted that there may be potential land contamination hotspots at Works Area WA2. As this area has been inaccessible for conducting site investigation during the EIA stage, land contamination assessment has not been conducted accordingly. When the site becomes accessible, a review of whether there would be potential hotspots would be carried out by further reconnaissance visits. If affirmative, land contamination assessment, and if necessary, remediation work would be conducted accordingly. Supplementary CAP, CAR and/or RAP and RR (if remediation work is necessary) would also be submitted to EPD for endorsement before the commencement of construction works at WA2.

11.5.2 Identification of Contamination Sources

11.5.2.1 Based on the initial site appraisal, reconnaissance site visit, review of previous SI and other relevant information as summarised in the endorsed CAP (Appendix 11B), the potential sources of land contamination relevant to the Trunk Road T2 project have been identified. The COCs for the site have been selected based on the historical land use information collected during the above initial site appraisal with reference to the Guidance Note for Contaminated Land Assessment and Remediation, Guidance Manual for Use of Risk-Based Remediation Goals for Contaminated Land Management. With respect to the historic land use information, the broad groups of selected COCs for this investigation include volatile organic compounds (BTEX: Benzene, Toluene, Ethylbenzene, Xylene), semi-volatile organic compounds (PAHs: Polycyclic Aromatic Hydrocarbons), metals, petroleum hydrocarbon, and PCBs.

11.5.3 Identification of Sensitive Receivers

11.5.3.1 Construction workers would be prone to exposure to any potential contaminated materials during the construction phase when conducting excavation of the concerned contaminated sites. The principle exposure routes would include:

· Direct ingestion of contaminated materials through eating or drinking on-site; and

· Dermal contact with contaminated materials.

11.5.3.2 Potential environmental impacts could, also, arise from any remediation works, if required, that is air emissions and water discharges, etc., that may affect the surrounding sensitive receivers including human receivers and water bodies. Proper mitigation measures should, therefore, be implemented as necessary.

11.5.3.3 There would be no sensitive receivers during the operational phase of the Trunk Road T2 Project which would be prone to the risk of potential land contamination, provided that the necessary remediation action and measures have been fully implemented.

11.5.4 Conceptual Site Model and Site Investigation

11.5.4.1 The conceptual site model is summarised in Table 11.9, based on which the sampling locations were devised as shown in Table 11.10 and Figure 11.2b.

Table 11.9 Conceptual Site Model

Potential Sources of Contamination	Potential Human Receptors	Potential Pathways	Preliminary Appraisal of Potential Impact
Potential contaminated fill materials previously used for the reclamation of the whole area at and adjacent to the South Apron of the former Kai Tak Airport.	Construction Phase Workers for the construction of the cut-and-cover tunnel at the site currently occupied by PCCW and a short section of Cheung Yip Street.	Potential direct and indirect contacts with contaminants in soil and/or groundwater when carrying out excavation works.	Potential contamination anticipated, as direct and indirect pathways for the exposure of human receptors to the possible source of contaminants exist.
	Operation Phase Road users of Trunk Road T2.	The cut-and-cover tunnel of the trunk road would physically separate any potential underground contamination sources, hence unlikely forming pathways for migration of contaminants.	Not anticipated, as no direct/indirect pathways for the exposure of human receptors to the possible source of contaminants.
	Operation Phase Users of the “Open Space” and “Other Specified Use” above the cut-and-cover tunnel of Trunk Road T2.	The area above cut-and-cover tunnel of the trunk road would physically separate any potential underground contamination sources, hence unlikely forming pathways for migration of contaminants.	Not anticipated, as no direct/indirect pathways for the exposure of human receptors to the possible source of contaminants.

Table 11.10 Summary of SI Works

No	Naming in CAP	Type	Status	Co-ordinates
				Easting	Northing
EH1	BH1	Inspection Pit	Terminated at 2.00m only due to encountering underground utilities	839762.67	819581.20
EH2	BH2	Borehole	Completed in accordance with CAP	839749.47	819569.25
EH3	BH3	Inspection Pit	Terminated at 1.10m only due to encountering underground utilities	839733.20	819559.26
EH4	BH4	Borehole	Completed in accordance with CAP	839782.94	819545.51
EH5	BH5	Borehole	Completed in accordance with CAP	839775.24	819534.01
TP1	TP6	Trial Pit	Completed in accordance with CAP	839761.03	819530.22
EH7	BH7	Borehole	Completed in accordance with CAP	839810.93	819522.46
EH8	BH8	Borehole	Completed in accordance with CAP	839799.52	819509.37
EH9	BH9	Borehole	Completed in accordance with CAP	839788.56	819499.70
EH10	BH10	Borehole	Completed in accordance with CAP	839839.01	819495.43
EH11	BH11	Borehole	Completed in accordance with CAP	839826.84	819481.95
EH12	BH12	Borehole	Completed in accordance with CAP	839817.16	819472.15
EH13	BH13	Borehole	Completed in accordance with CAP	839861.31	819473.41
EH13A	-	Borehole	Completed for re-sampling of only a groundwater sample for EH13 due to loss of sample before the laboratory analysis.	839861.69	819472.92
EH14	BH14	Borehole	Completed in accordance with CAP	839851.09	819462.10
EH15	BH15	Borehole	Completed in accordance with CAP	839845.05	819446.42

* Re-sampling of a groundwater sample was carried out at EH13 due to loss of sample

11.5.5 Contaminated Land Assessment

Ground Conditions

11.5.5.1 The general ground conditions were shown to be a top layer of fill materials, below a concrete paving of ~200-300mm at some locations, down to ~9m mainly consisting of silt to fine coarse sand and gravel of fill materials. Groundwater was encountered at all borehole locations during the course of drilling and excavation due to low groundwater table in the study area near the coastline. The strata logging records are included in the CAR in Appendix 11B.

Soil Contamination

11.5.5.2 A total of 53 soil samples were collected in this SI for land contamination (Appendix 11B). There were 48 soil samples collected from 4 depths of 12 boreholes namely EH2, EH4, EH5, EH7, EH8, EH9, EH10, EH11, EH12, EH13, EH14 and EH15 as shown in Figure 11.2b. Another 3 soil samples were collected at 3 depths of a trial pit at TP1. Another 2 samples were collected at below ground level of 2 inspection pits at EH1 and EH3.

11.5.5.3 It should be noted that at EH1 and EH3 as shown in Figure 11.2b, due to encountering underground utilities at ~2.0m below ground level during the formation of the inspection pit, sampling did not proceed further. Alternative locations adjacent to both EH1 and EH3 have been attempted for re-location and sampling, but they were also constrained by similar underground utility issues. Other locations at Cheung Yip Street have also been reviewed, but the site access constraints at the existing vehicular road did not allow any further sampling SI works to be carried out. The remaining SI works at these two sampling locations should be carried out when these sampling locations are accessible and the supplementary CAR and/or RAP and RR (if remediation work is necessary) for the remaining SI works should be submitted to the EPD for approval/endorsement before the commencement of construction works.

11.5.5.4 A summary of laboratory results and reports for the tested COCs are provided in the CAR in Appendix 11B. Section 11.3.2.4 stated the land use classification as “Industrial” and “Public Park”, and the corresponding RBRGs adopted for the land contamination assessment are shown in Table 11.2. For the soil samples collected, the concentrations of petroleum hydrocarbon, VOCs, SVOC and PCBs were all below the reporting limits of the laboratory. The concentrations of metals were mostly determined above the reporting limits but they were well below the RBRGs criteria. There were no exceedances of the RBRGs determined for all the soil samples collected in the SI.

Groundwater Contamination

11.5.5.5 There were 13 groundwater samples at the 12 boreholes and 1 trial pit location as shown in Figure 11.2b. A summary of laboratory results and the laboratory reports are provided in the CAR in Appendix 11B. Section 11.3.2.4 stated the land use classification as “Industrial” and “Public Park”, and the corresponding RBRGs adopted for the land contamination assessment are shown in Table 11.3. As described above, it should be noted that no groundwater was collected at EH1 and EH3 due to encountering underground utilities and the inspection pits/boreholes ceased at ~2.0m below ground level where no ground water was encountered. All of the tested COCs in the groundwater sample were below the reporting limits of the laboratory or at very low levels, and there was no exceedance of the RBRGs criteria. It should, also, be noted that a re-sampling of a groundwater sample (only) was carried out by constructing a new borehole (EH13A) due to the loss of the groundwater sample at EH13 before the laboratory analysis.

Conclusions

11.5.5.6 A total of 53 soil samples and 13 groundwater samples were collected in this SI for land contamination. There were no exceedances of the corresponding RBRGs criteria and no adverse impact due to land contamination would be anticipated.

11.5.5.7 However, there were 2 locations, i.e. EH1 and EH3, at which the SI works were not accessible during the site investigation mentioned above for this land contamination assessment due to site access constraints at Cheung Yip Street. As such, in future, if the concerned locations are confirmed to be acquired as part of the works sites for the Trunk Road T2 construction contract and access is permitted, a supplementary SI to complete the land contamination assessment for EH1 and EH3 would be conducted in accordance with the requirements as set out in the endorsed CAP prior to the commencement of construction works so as to verify if any potential land contamination issues exist in these remaining areas. The findings of such supplementary SI works would be submitted as supplementary information to the CAR. If land contamination is determined, the necessary remediation works will be proposed in a RAP for implementation. Following the completion of remaining SI works at locations EH1 and EH3, a supplementary CAR and/or RAP will be submitted to EPD for approval before the commencement of construction works.

11.5.6 Mitigation Measures

11.5.6.1 As there were no predicted exceedances of the collected soil and groundwater samples in this SI for land contamination, no specific mitigation measures are required.

11.6 Summary and Conclusions

11.6.1 Waste Management

11.6.1.1 With the implementation of the recommended mitigation measures, there would be no adverse residual impacts associated with the handling, storage, transportation or disposal of the waste generated by the Trunk Road T2 project during the construction and operation phases.

11.6.2 Contaminated Land

11.6.2.1 As there were no exceedances of the RBRGs criteria for the land contamination for the Trunk Road T2 project, there would be no adverse impacts due to land contamination anticipated.