7.1.1 The key environmental issues in respect of the waste management implications associated with the Project are identified below.
· Construction impact from general site wastes and refuse from workforce on site, maintenance and chemical wastes from vehicle and equipment maintenance activities, and construction and demolition material from excavation works for building towers.
· Operational impact from waste generated from the new development area.
Environmental Impact Assessment Ordinance (EIAO), Cap. 499, S16
Annex 7 Criteria for Evaluating Waste Management Implications
Annex 15 Guidelines for Assessment of Waste Management Implications
Waste Disposal Ordinance (WDO)
7.2.2
The principal legislation
controlling waste materials in
7.2.3 Under the Waste Disposal (Chemical Waste) (General) Regulation, a chemical waste includes any substance which is a scrap material or by-product arising from industrial/trade activities, as specified under Schedule 1 of the WDO, in such form, quantity and concentration that it will cause pollution or constitute a danger to health or risk to the environment. A complete list of such substances is provided under the Ordinance. A chemical waste producer will be required under the Ordinance to register with the Director of Environmental Protection and must treat their wastes, utilising on-site plant licensed by the EPD, or have a licensed collector take the wastes to a licensed facility (such as the Chemical Waste Treatment Centre (CWTC) located at Tsing Yi, which was commissioned in June 1993, and is designed to treat most of the chemical waste from the territory). In addition, any contractor employed for the collection of chemical waste must be a registered chemical waste collector under the Ordinance. For each consignment of wastes, the waste producer, collector and disposer of the wastes must sign all relevant parts of a computerised trip ticket. This system is designed to allow the transfer of wastes to be traced from cradle to grave.
7.2.4 Asbestos waste is classified as chemical waste under the Waste Disposal (Chemical Waste) (General) Regulation and its handling, collection, transportation and disposal is controlled by the legislation. A Code of Practice on the Handling, Transportation and Disposal of Asbestos Waste is published by EPD under the WDO. The purpose of this Code is to provide guidance and advice on the collection, storage, treatment, transportation and disposal of asbestos waste. A separate code of practice, entitled Code of Practice on Asbestos Control, is issued by EPD under the Air Pollution Control Ordinance. This Code of Practice comprises 4 sets of documents and provides advice on matters relating to preparation of asbestos investigation report, asbestos management plan and asbestos abatement plan; asbestos work using full containment or mini containment method; asbestos work using glove bag method; and safe handling of low risk asbestos containing material.
7.2.5 The Hong Kong Planning Standards and Guidelines (HKPSG), Chapter 9 (Environment), provides information on the required methods of treatment and disposal of different types wastes.
Works Branch Technical Circular (WBTC) No. 2/93
7.2.6 The current policy relating to the dumping of construction and demolition (C&D) material is documented in the Works Branch Technical Circular No. 2/93, ‘Public Dumps’. In order to dispose of the inert portion of C&D material (named as public fill) in a public filling area, a license is required which is issued by the CED. The Works Branch Technical Circular states that C&D material suitable for use as fill material should not be disposed of to landfill, but placed in public filling area or reclamation and land formation projects. The Public Fill Committee (PFC) together with Project Departments are responsible for considering the suitability of a site as a public filling area.
7.2.7 In addition to the Works Branch Circular, EPD and CED have produced a leaflet titled `New Disposal Arrangements for Construction Waste' which states that C&D material with less than 20% by volume of inert material (i.e. public fill) will be accepted at landfill. If the material contains more than 20% inert material, the waste must be sorted with suitable material sent to public filling area and the non-inert material (i.e. C&D waste) sent to landfill for final disposal.
7.3 Construction Phase Assessment
Construction and Demolition (C&D) Material
7.3.1 Construction of roads and facilities will require excavation for pavements, stormwater drains, sewers, water mains and other ducting and services. As the internal access road layout and the range of infrastructure to be provided is similar for the proposed Minimised Reclamation and Full Reclamation development options (with and without I/R interface), the volume of C&D material generated is anticipated to be similar for the construction of the four proposed development options. It is estimated that a total of approximately 162,833 m3 of construction and demolition (C&D) material will be generated from Phase 2, 3 and 4 of the YTB development, mainly arising from the excavation of the basement of building towers, and the commercial building foundation. From the provisional development programme, the first construction phase of the YTB development will be carried out concurrently with the Phase 2 reclamation and Phase 1 preloading. With careful management, the excavated material generated from the first construction phase of the YTB development could be reused on-site for reclamation.
7.3.2 The preloading mound from the Phase 2 Reclamation (i.e. approximately 33,998m3 of public fill) will require off-site disposal, bringing the total surplus C&D material generated from the construction of the YTB development to 196,830 m3. All preloading mound for the Phase 1 Reclamation will be used for the Phase 2 Reclamation and Phase 2 Preloading Mound. Of the C&D material generated from Phase 2, 3 and 4 of the YTB development, it is estimated that a total of 161,205 m3 (approximately 99%) is public fill which will require off-site disposal to public filling areas. The remaining 1,628 m3 of C&D waste will require disposal at landfill. The volume of surplus C&D material requiring off-site disposal is summarized below in Table 7.1.
Table 7.1 Breakdown of Surplus C&D Material from YTB Development
|
Source of C&D Material |
Volume (m3) |
|
|
Excavated material from
Phase 2, 3, and 4 YTB Development & commercial building foundation |
162,833 m3 |
Comprising 161,205 m3
of public fill & 1,628 m3 of C&D waste |
|
Phase 2 Reclamation Preloading
mound requiring off-site disposal |
33,998 m3 |
Public fill |
|
Total surplus C&D
material for off-site disposal |
196,830 m3 |
|
7.3.3 By reducing the quantity of C&D material requiring off-site disposal through the reuse of public fill on-site, the potential for traffic impacts during the transportation of material will also be reduced. The additional traffic flow due to the transportation of construction material from vehicle movements in and out of site is considered insignificant.
7.3.4 It is recommended that C&D material should be re-used or recycled where possible. Suitable disposal methods are recommended in Table 7.2. As discussed in Section 7.2.7, C&D waste with less than 20% by volume of inert material will be accepted at landfill. If the material contains more than 20% public fill, the waste must be sorted with suitable material and sent to public filling area and the non-inert material (i.e. C&D waste) sent to landfill for final disposal. It should be noted that public fill material should only consist of earth, inert building debris, broken rock and concrete, brick and cement plaster/mortar. The material should be free from marine mud, household refuse, plastics, metals, industrial and chemical waste, animal and vegetable matter. A sorting facility should be used to sort and process construction material generated from the site activities. The sorting process should be carefully monitored to avoid contamination of the public fill.
Chemical Waste
7.3.5 Construction plant and equipment will require regular maintenance and servicing which will generate waste. Substances generated are likely to include some chemical wastes such as cleaning fluids, solvents, lubrication oil and fuel.
7.3.6 Vehicle and equipment maintenance activities will involve the use of a variety of chemicals, oil and lubricants, including heavy duty cleaners, organic solvents, degreasers, brake fluids, battery acid and soldering fluids. The cumulative effect of a potentially large number of small spillages during maintenance operations by faulty equipment, accidents, carelessness and deliberate discharge to drain may be significant.
7.3.7 The service shop and maintenance facility should be located on hard standings within a bunded area, sumps and oil interceptors should be provided. Maintenance of vehicles and equipment involving activities with potential leakages and spillage should only be undertaken with the areas appropriately equipped to control these discharges.
7.3.8 Materials classified as chemical wastes will need special handling and storage arrangements before removal for appropriate treatment at the chemical waste treatment facility (CWTF). Whenever possible opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for chemical wastes are detailed in Sections 7.3.20 to 7.3.22. Provided that the handling, storage and disposal of chemical wastes are in accordance with these requirements, adverse environmental impacts should not result.
Workforce Waste and General Site Wastes
7.3.9 Throughout construction, the workforce will generate general refuse, comprising food scraps, paper, empty containers etc.
7.3.10 Rapid and effective collection of site wastes will be required to prevent waste materials being blown around by wind, flushed or leached into the marine environment, and odour nuisancee. Suitable collection sites around site offices, service buildings and canteen will be required. It is recommended that for environmental hygiene reasons general refuse are not stored for a period exceeding 48 hours, however, removal every 24 hours is preferable. The refuse will not be suitable for incorporation into any reclamation works.
7.3.11 Materials and equipment used on site will produce packaging and container wastes. Measures should include provision of a collection area where waste can be stored and loaded prior to removal from site. An enclosed and covered area is preferred to reduce the occurrence of ‘wind blow’ light material. If an open area is unavoidable for the storage or loading/unloading of wastes, then the area should be bunded and all polluted surface run-off collected within this area should be diverted to sewers. With the implementation of the good site practices described in Sections 7.3.13 and 7.3.15 and the recommended mitigation measures in Sections 7.3.23 to 7.3.24, the potential environmental impacts resulting from the storage, handling and transportation of general site wastes are expected to be minimal.
Mitigation Proposals
7.3.12 This section outlines appropriate mitigation measures to minimise any impact associated with the identified construction phase waste arisings. These recommended measures apply to all four proposed development options at YTB.
Good Site Practice and Waste Reduction Measures
7.3.13 It is not expected that significant waste management related impacts would arise, provided good site practice (GSP) is adhered to. Recommendations for GSP for wastes include:
· Nomination of an approved personnel, 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;
· Training of site personnel in proper waste management and chemical handling procedures;
· Provision of sufficient waste disposal points and regular collection for disposal;
· Appropriate measures should be employed to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;
· Separation of chemical wastes for special handling and appropriate treatment at the Chemical Waste Treatment Facility; and
· Regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors.
7.3.14 In order to monitor the disposal of C&D material and solid wastes at public filling areas and landfills, and to control fly-tipping, a trip-ticket system should be included as one of the contractual requirements and implemented by the Environmental Team. An Independent Checker (Environment) should be responsible for auditing the result of the system.
7.3.15 Good management and control can prevent the generation of significant amounts 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 are as follows:
· 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;
· To encourage collection of aluminium cans by individual collectors, separate labeled bins should be provided to segregate this waste from other general refuse generated by the workforce;
· Any unused chemicals or those with remaining functional capacity should be recycled;
· Maximizing the use of reusable steel formwork and metal site hoarding to reduce the amount of C&D material;
· Prior to disposal of C&D waste, it is recommended that wood, steel and other metals be separated for re-use and/or recycling to minimise the quantity of waste to be disposed of to landfill;
· Proper storage and site practices to minimise the potential for damage or contamination of construction materials; and
· Plan and stock construction materials carefully to minimize amount of waste generated and avoid unnecessary generation of waste.
7.3.16 A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be proposed. Quantities could be determined by weighing each load or other suitable methods.
7.3.17 In addition to the above good site practices and waste reduction measures, specific mitigation measures are recommended below for the identified waste arisings to minimize environmental impacts during the handling, transportation and disposal of these wastes:
Construction and Demolition (C&D) Material
7.3.18 A large quantity of construction and demolition material (196,830 m3) would be generated from the Project. In order to minimize the impact resulting from collection and transportation of material for off-site disposal, on-site waste separation, processing and storage facilities are recommended. C&D material should be separated on-site into three categories: (i) public fill, the inert portion of the material, which should be re-used on-site or disposed of at a public filling area (e.g. concrete, brick, rock and soil); (ii) the non-inert portion of the material (i.e. C&D waste) which can be re-used and/or recycled (e.g. wood, plastic, steel and other metals); (iii) the non-inert portion of the material which cannot be re-used and/or recycled which would require landfill disposal.
7.3.19
A crusher/construction material
sorting facility should be provided. The
facility would be used to sort and process material generated from the
construction activities. The sorting
process should be carefully monitored to avoid mixing of the three categories
of waste material as described above. 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. An identified location for
these areas is near the proposed retention tank to be sited near
Maintenance and Chemical Waste
7.3.20 Chemical waste produced from the construction activities should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes and disposed of by a licenced contractor at CWTF.
7.3.21 In addition, the following mitigation measures shall be adopted to prevent the uncontrolled disposal of chemical and hazardous waste into the air, soil and waters:
· Drainage serving an open oil or petrol filling point or from vehicle and plant servicing areas shall be connected to the site drainage system via a petrol/oil interceptor with storm water bypass.
· Proper operational maintenance and inspection programme for plant and equipment shall be carried out to minimize problems from leakage and accidental spillages of oils and petrol. Any such leakages or spillage shall be contained and cleaned up immediately.
7.3.22 Where tanks are to be emptied or removed, precautionary measures should be taken to avoid the spillage of any petroleum products which may cause contamination to the ground. Any contaminated materials such as absorbent or cleaning materials should be disposed of properly.
General
Site Wastes
7.3.23 A collection area should be provided where waste can be stored and loaded prior to removal from site. An enclosed and covered area is preferred to reduce the occurrence of 'wind blow' light material. If an open area is unavoidable for the storage or loading/unloading of wastes, then the area should be bunded and all the polluted surface run-off collected within this area should be diverted into sewers.
Workforce
Wastes
7.3.24 Suitable collection sites around site offices and canteen will be required. It is recommended that for environmental hygiene reasons and to minimise odour, putrescible wastes are not stored for a period exceeding 48 hours, however, removal every 24 hours is preferable.
7.3.25 Table 7.2 provides a summary of waste handling methods for different types of waste for the four proposed development options.
Table 7.2 Summary of Waste Handling Procedures during Construction Phase
|
Waste Type |
Mitigation Measures |
|
|
Handling |
Disposal |
|
|
Construction |
||
|
Construction and
Demolition Material |
Where possible inert
portion (i.e. public fill) should be re-used on-site |
On-site for reclamation
and road base |
|
|
If off-site disposal
required, separate into: ·
Public fill (e.g. concrete and rubble) ·
C&D waste for re-use and/or recycling (e.g.
wood, plastic, steel and other metals) |
Public filling area or
reclamation To be determined at a
later stage |
|
|
·
C&D waste which cannot be re-used and/or
recycled |
Landfill |
|
Maintenance and Chemical
Wastes |
·
Recycle on-site or by licensed companies ·
Stored on-site within suitably designed containers
|
Chemical Waste
Treatment Facility |
|
|
Asbestos: ·
Provision of appropriate on-site temporary storage
facility where necessary ·
To be removed off-site by registered contractors |
Landfill |
|
Workforce Waste |
·
Provide on-site refuse collection facilities ·
Main sewer or septic tank |
Refuse Station for compaction
and containerisation and then to landfill Private hygiene company |
|
Operation |
||
|
Municipal Waste |
Provide on-site refuse
collection chambers (RCC) |
Landfill, collection by
public or private company |
7.4 Operational Phase Assessment
7.4.1 The proposed future development at the four development options will accommodate a residential population of about 39,000 after full occupation. There will also be 20,920 employees working in the area. The estimated quantity of wastes generated from the development in 2016 will be 78,921 kg/day of which 45,240 kg/day will be from residential sector and 33,681 kg/day from the commercial/industrial sector [1].
7.4.2 Refuse collection chambers (RCC) will be provided for the residential development as well as the office/retail development. Each refuse collection chamber will be enclosed within the podium and will serve approximately 3 to 4 numbers of building blocks subject to further review at the detailed design stage. Mechanical ventilation will be provided in order to comply with Building Regulation. Odour absorption system such as carbon filter will be incorporated into the mechanical ventilation system to minimize the odour nuisance to the public. With proper management and maintenance of the waste facilities, possible leachate impact from the RCC is not anticipated.
7.4.3 It is also recommended that collection bins for used aluminium cans, waste paper and glass bottles should be provided at strategic locations of the development site to encourage recycling by residents during the operational phase of the project.
Introduction
7.5.1 The waste management implications associated with the Project are summarised in the following sections. An implementation schedule of the proposed mitigation measures is given in Section 12.
Construction Phase
7.5.1 During the construction phase of the four proposed development options, wastes generated by construction works are likely to include construction and demolition material, workforce waste and general site wastes and maintenance and chemical wastes. Chemical waste produced from the construction activities should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes and disposed of by a licenced contractor. The Project is not expected to generate significant waste management related impacts, provided that proper mitigation measures are implemented and good site practice (GSP) is adhered to.
Operational Phase
7.5.2 The estimated quantity of wastes generated from the proposed future development for the four development options in 2016 will be around 78,921 kg/day, of which 45,240 kg/day will be from residential sector and 33,681 kg/day from the commercial/industrial sector. Refuse collection chambers (RCC) will be provided for the residential development as well as the office/retail development.
[1] Data from
Monitoring in Solid Waste in
