4 Waste Management Implications

4.1 Introduction

4.1.1 Waste management issues associated with the decommissioning works of the Project would mainly be related to construction and demolition (C&D) materials generated from demolition of the remaining structures within the Project boundary. Potential environmental impacts that may result from these identified waste arisings are evaluated, and mitigation measures on the handling, transportation and disposal of these wastes are recommended with reference to the applicable waste legislation and guidelines.

4.2 Environmental Legislation, Policies, Plans, Standards and Criteria

4.2.1 The criteria and guidelines for assessing waste management implications are set out in Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact Assessment Ordinance (EIAO-TM), respectively.

4.2.2 The following legislation relates to the handling, treatment and disposal of wastes in the Hong Kong SAR and has been used in assessing potential impacts:

l Waste Disposal Ordinance (Cap. 354)

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

l Land (Miscellaneous Provisions) Ordinance (Cap. 28)

l Public Health and Municipal Services Ordinance (Cap. 132) - Public Cleansing and Prevention of Nuisances Regulation

l Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap. 354N)

Waste Management

4.2.3 The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal of wastes. Construction waste is defined as any substance, matter or thing that is generated from construction work 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 the WDO, wastes can be disposed of only at designated waste disposal facilities.

4.2.4 Under the WDO, the Chemical Waste (General) Regulation provides regulations for chemical waste control, and administers the possession, storage, collection, transport and disposal of chemical wastes. The Environmental Protection Department (EPD) has also issued a guideline document, the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes (1992), which details how the contractor should comply with the regulations on chemical wastes.

4.2.5 The Public Cleansing and Prevention of Nuisances Regulation provides control on illegal tipping of wastes on unauthorised (unlicensed) sites.

Chemical Waste

4.2.6 Under the Waste Disposal (Chemical Waste) (General) Regulations, all producers of chemical waste must register with EPD and treat their wastes, either utilising on-site plant licensed by EPD, or arranging for a licensed collector to transport the wastes to a licensed facility. The regulation also prescribes the storage facilities to be provided on site, including labelling and warning signs, and requires the preparation of written procedures and training to deal with emergencies such as spillages, leakages or accidents arising from the storage of chemical wastes.

Construction and Demolition (C&D) Material

4.2.7 The current policy related to the disposal of C&D material is documented in the Works Branch Technical Circular No. 2/93, ‘Public Dumps’. Construction and demolition materials that are wholly inert, namely public fill, should not be disposed of to landfill, but taken to public filling areas, which usually form part of reclamation schemes. The Land (Miscellaneous Provisions) Ordinance requires that dumping licences be obtained by individuals or companies who deliver public fill to public filling areas. The Civil Engineering and Development Department (CEDD) issues the licences under delegated powers from the Director of Lands.

4.2.8 Under the Waste Disposal (Charges for Disposal of Construction Waste) Regulation, enacted in January 2006, construction waste delivered to a landfill for disposal must not contain more than 50% by weight of inert material. Construction waste delivered to a sorting facility for disposal must contain more than 50% by weight of inert material, and construction waste delivered to a public fill reception facility for disposal must consist entirely of inert material. In accordance with the Environment, Transport and Works Bureau (ETWB) TCW No. 31/2004 “Trip Ticket System for Disposal of Construction and Demolition Materials”, for 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 Public Fill Committee (PFC) through the Secretary of the PFC to request 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 Director of Environmental Protection (DEP) as to whether landfill facilities will be available for disposal of such materials. The DEP 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 DEP for designated landfill facilities. However, the project office should still specify in the tender documents appropriate landfill facilities (e.g. Outlying Islands Transfer Facilities managed by the EPD, SENT Landfill at Tseung Kwan O, NENT Landfill at Ta Kwu Ling and WENT Landfill at Nim Wan.).

4.2.9 Measures have been introduced under ETWB TCW No. 33/2002, “Management of Construction and Demolition Material Including Rock” to enhance the management of construction and demolition material, and to minimize its generation at source. The enhancement measures include: (i) drawing up a Construction and Demolition Material Management Plan (C&DMMP) at the feasibility study or preliminary design stage to minimize C&D material generation and encourage proper management of such material; (ii) vetting of the C&DMMP prior to upgrading of the project to Category A in the Public Works Programme; and (iii) providing the contractor with information from the C&DMMP in order to facilitate him in the preparation of the Waste Management Plan (WMP) and to minimize C&D material generation during construction. Projects generating C&D material less than 50,000m³ or importing fill material less than 50,000m³ are exempt from the C&DMMP. The new ETWB TCW No. 19/2005 “Environmental Management on Construction Sites” includes procedures on waste management requiring contractors to reduce the C&D material to be disposed of during the course of construction. Under ETWB TCW No. 19/2005, the contractor is required to prepare and implement an Environmental Management Plan (EMP) and the WMP becomes part of the EMP. Besides, ETWB TCW No.31/2004 “Trip Ticket System for Disposal of Construction and Demolition Materials” promulgates the latest trip ticket system for public works contracts including capital works contracts, term contracts and design and build contracts, where C&D materials including waste generated on site require disposal.

4.3 Assessment Methodology

General

4.3.1 The criteria for assessing waste management implications are outlined in Annex 7 of the EIAO-TM. The methods for assessing potential waste management impacts during the decommissioning works follow those presented in Annex 15 of the EIAO-TM and include the following:

l Estimation of the types and quantities of the wastes generated;

l Assessment of potential impacts from the management of solid waste with respect to potential hazards, air and odour emissions, noise, wastewater discharge and transport; and

l Assessment of impacts on the capacity of waste collection, transfer and disposal facilities.

4.4 Identification of Environmental Impacts

4.4.1 The decommissioning works to be carried out for the Project would generate a variety of wastes that can be divided into distinct categories based on their composition and ultimate method of disposal. The identified waste types include:

l C&D material

l Chemical waste

l General refuse

4.4.2 As discussed in Section 3 of this report, all the contaminated soil should be treated on-site by biopiling and/or cement solidification / stabilization. After the decontamination works, the treated soil should be backfilled or re-sue as far as practicable. As a result, no off-site disposal of contaminated / decontaminated soil is required under this Project.

4.4.3 Each type of waste arising is described below, together with an evaluation of the potential environmental impacts associated with the handling, storage and transport of the waste.

4.4.4 The disused fuel dolphin is located outside the limit of the former Kai Tak Airport. However, the fuel pipelines are considered as part of the fuelling facilities of the former Kai Tak Airport and hence the possible environmental impacts arising from the decommissioning of these facilities are also reviewed under this EIA study. As discussed in Section 2.4 of this report, the disused fuel dolphin structure will be demolished down to 1m below the existing seabed and the disused fuel pipeline would be left in-situ and, if necessary, grouted with concrete. With this proposed decommissioning method of the disused fuel dolphin and the associated abandoned fuel pipelines, there would be no need for dredging and off-site disposal of dredged sediment would thus not be required. During the demolition works, the sediment around the piles of the disused fuel dolphin structure would be moved aside and after cutting of the piles, the sediment would be pushed back or levelled out.

4.5 Prediction and Evaluation of Environmental Impacts

C&D Material

4.5.1 C&D material will be generated from the decommissioning and decontamination works described in Section 2 of this Report. The estimated volume of C&D material from the decommissioning and decontamination works is given in Table 4.1 below. Due to the unforeseeable or unsuitable condition of the demolition material (i.e. pipeline, metal, reinforced concrete etc) it is not feasible to reuse this C&D material on-site.

^{Table 4.1}^E^{stimated Quantities of C&D Material from Decommissioning and
Decontamination Works and the Potential Disposal Sites}

Works Item	Disposal Site (Landfill or Public Fill)	Estimated Quantity (m³)
Excavate/remove the underground fuel tank and the fuel supply system at the ex-GFS apron area	Landfill disposal	500
Excavate/remove the fuel pipeline along south apron (excluding the ex-GFS apron area)	Landfill disposal	3200
Demolish/remove the disused fuel dolphin	Landfill and public fill disposal	400 (landfill: 200; Public fill: 200)
	Total	4100 (landfill: 3900; public fill: 200)

4.5.2 C&D material generated from the demolition works will be sorted on-site into public fill (i.e. inert C&D material) and C&D waste. The inert C&D material would require disposal to the designated public fill reception facility. C&D waste, such as steel and other metals, should be reused or recycled and, as a last resort, disposed of to landfill. Mitigation and control requirements for C&D material are detailed in Section 4.6. Provided that the good site practices and control requirements for C&D material are properly implemented, adverse environmental impacts on potential hazard, air and odour emissions, noise, wastewater discharge, and public transport are not expected.

Chemical Waste

4.5.3 The operation, maintenance, and servicing of construction and decontamination treatment plant and equipment may generate some chemical wastes such as cleaning fluids, solvents, lubrication oil, fuel, and used carbon filters. It is difficult to quantify the amount of chemical waste that will arise during the decommissioning and decontamination works since it will be dependent on the contractor’s on-site operation and maintenance requirements and the amount of plant utilized. However, it is anticipated that the quantity of chemical waste, such as lubricating oil, solvent produced from plant maintenance, and used carbon filters would be small and in the order of a few cubic metres per month. The amount of chemical waste to be generated will be quantified in the site Waste Management Plan to be prepared by the contractor.

4.5.4 Chemical wastes arising during the decommissioning works may pose environmental, health and safety hazards if not stored and disposed of in an appropriate manner as stipulated in the Waste Disposal (Chemical Waste) (General) Regulations. The potential hazards include:

l Toxic effects to workers

l Adverse impacts on water quality from spills

l Fire hazards

4.5.5 Materials classified as chemical wastes will require special handling and storage arrangements before removal for appropriate treatment at the Chemical Waste Treatment Facility (CWTF) or other licensed facility. Wherever possible, opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for chemical wastes are detailed in Section 4.6. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts on potential hazard, air and odour emissions, noise, wastewater discharge, and public transport are not expected.

General Refuse

4.5.6 The construction workforce would generate general refuse comprising food scraps, waste paper, empty containers, etc. Such refuse should be properly managed so that intentional or accidental release to the surrounding environment would not occur. Disposal of refuse at sites other than approved waste transfer or disposal facilities shall be prohibited. Effective collection of site wastes would be required to prevent waste materials being blown around by wind, wastewater discharge by flushing or leaching into the marine environment, or creating odour nuisance or pest and vermin problem. With the implementation of waste management practices at the site (as recommended in Section 4.6), adverse environmental impacts on potential hazard, air and odour emissions, noise, wastewater discharge, and public transport would not be expected from the storage, handling and transportation of refuse.

4.6 Mitigation of Adverse Environmental Impacts

Good Site Practices

4.6.1 Adverse impacts related to waste management are not expected to arise, provided that good site practices are strictly followed. Recommendations for good site practices during the decommissioning works include:

l Nomination of an approved person, such as a site manager, to be responsible for good site practices, arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site.

l Training of site personnel in proper waste management and chemical waste handling procedures.

l Provision of sufficient waste disposal points and regular collection for disposal.

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

l Regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors.

l A recording system for the amount of wastes generated, recycled and disposed of (including the disposal sites).

Waste Reduction Measures

4.6.2 Good management and control can prevent the generation of a significant amount of waste. Waste reduction is best achieved at the planning and design stage, as well as by ensuring the implementation of good site practices. Recommendations to achieve waste reduction include:

l Sort C&D waste from demolition of the remaining structures to recover recyclable portions such as metals.

l Segregation and storage of different types of waste in different containers, skips or stockpiles to enhance reuse or recycling of materials and their proper disposal.

l Encourage collection of aluminium cans, PET bottles and paper by providing separate labelled bins to enable these wastes to be segregated from other general refuse generated by the work force.

l Any unused chemicals or those with remaining functional capacity shall be recycled.

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

l Plan and stock construction materials carefully to minimise amount of waste generated and avoid unnecessary generation of waste.

4.6.3 In addition to the above measures, specific mitigation measures are recommended below for the identified waste arisings to minimise environmental impacts during handling, transportation and disposal of these wastes.

Construction and Demolition Material

4.6.4 The C&D material should be sorted on-site into inert C&D material (that is, public fill) and C&D waste. The inert C&D material would require disposal to the designated public fill reception facility. C&D material should be transported from the site by barge wherever possible to reduce the environmental impacts associated with road transportation. C&D waste, such as steel and other metals should be re-used or recycled and, as a last resort, disposed of to landfill. It is recommended that a suitable area be designated to facilitate the sorting process and a temporary stockpiling area will be required for the separated materials.

4.6.5 In order to monitor the disposal of public fill and C&D waste at public filling facilities and landfills, respectively, and to control fly tipping, a trip-ticket system as promulgated under ETWB TCW No. 31/2004 “Trip Ticket System for Disposal of Construction and Demolition Materials” should be included as one of the contractual requirements and implemented by an Environmental Team undertaking the Environmental Monitoring and Audit work. An Independent Environmental Checker should be responsible for auditing the results of the system.

General Refuse

4.6.6 General refuse should be stored in enclosed bins or compaction units separate from C&D material. A licensed waste collector should be employed by the contractor to remove general refuse from the site, separately from C&D material. Effective collection and storage methods (including enclosed and covered area) of site wastes would be required to prevent waste materials from being blown around by wind, wastewater discharge by flushing or leaching into the marine environment, or creating odour nuisance or pest and vermin problem.

Chemical Wastes

4.6.7 After use, chemical wastes (for example, cleaning fluids, solvents, lubrication oil and fuel) should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes. Spent chemicals should be collected by a licensed collector for disposal at the CWTF or other licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

Wastes Handling and Disposal Routes

4.6.8 Table 4.2 provides a summary of the various waste types likely to be generated during the decommissioning works, together with the recommended handling and disposal methods.

^{Table 4.2}^{Summary of Waste Handling Procedures and Disposal Routes}

Waste Type	Generated From Works Item	Total Quantity Generated	Quantity to be disposed off-site / re-used	Handling	Disposal
C&D Material	Demolition of Remaining Structures	4100 m³	4100 m³ (no reuse is considered feasible)	Sort on-site into: · Inert C&D material (public fill) (200 m³) · C&D waste (3900 m³ )	· To be disposed to public fill reception facilities for other beneficial uses · To be disposed to landfill
Chemical Wastes	Lubrication oil, fuel etc. from operation, maintenance, and servicing of construction and decontamination treatment plant and equipment	Few cubic metres per month (preliminary estimate)	Few cubic metres per month (preliminary estimate)	Recycle on-site or by licensed companies Stored on-site within suitably designed containers	· Chemical Waste Treatment Facility or other licensed facility
General Refuse	Waste paper, discarded containers etc. generated from workforce	Few cubic metres per month (preliminary estimate)	Few cubic metres per month (preliminary estimate)	Provide on-site refuse collection points	· Refuse station for compaction and containerisation and then to landfill

4.7 Evaluation of Residual Impacts

4.7.1 With the implementation of the recommended mitigation measures for the handling, transportation and disposal of the identified waste arisings, no residual impact is expected to arise during the decommissioning works of the Project.

4.8 Environmental Monitoring and Audit

4.8.1 Waste management will be the contractor’s responsibility to ensure that all wastes produced during the decommissioning works are handled, stored and disposed of in accordance with good waste management practices and EPD’s regulations and requirements. The mitigation measures recommended in Section 4.6 should form the basis of the site Waste Management Plan to be developed by the contractor in the construction stage.

4.9 Conclusion

4.9.1 Wastes generated by the decommissioning works are likely to include C&D material from demolition of the remaining structures within the Project boundary, general refuse from the workforce and chemical waste from the maintenance of construction plant and equipment and from the soil remediation process. Provided that these identified waste arisings are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts would not be expected during the decommissioning works and from the soil remediation process of the Project.