8.1.1. This section identifies the types of waste that may arise from the construction and operation phases of the proposed Project.
8.1.2. This assessment has based on the criteria and guidelines stated in Annexes 7 and 15 of the EIAO-TM and scope outlined in clause 3.4.8 and Appendix E1 of the EIA Study Brief (No. ESB-267/2014) for evaluating and assessing waste management implications.
8.2.1. The following legislations governing waste management and disposal in Hong Kong are considered in assessing potential waste management implications:
· The Waste Disposal Ordinance (Cap.354) and subsidiary legislation such as the Waste Disposal (Chemical Waste) (General) Regulation and Waste Disposal (Charges for Disposal of Construction Waste) Regulation that set out requirements for the storage, handling and transportation of all types of wastes;
· Environmental Impact Assessment Ordinance (Cap. 499), Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annexes 7 and 15;
· Public Health and Municipal Service Ordinance (Cap. 132), Public Cleansing and Prevention of Nuisance Regulation;
· Buildings Ordinance (Cap. 123);
· Dumping at Sea Ordinance (Cap. 466); and
· Land (Miscellaneous Provisions) Ordinance (Cap. 28).
8.2.2. Other relevant documents and guidelines that are applicable to waste management and disposal in Hong Kong include:
· Development Bureau Technical Circular (Works) (TC(W)) No. 6/2010, Trip Ticket System for Disposal of Construction & Demolition Materials;
· Development Bureau TC(W) No. 8/2010 Enhanced Specification for Site Cleanliness and Tidiness;
· ETWB TC(W) No. 34/2002, Management of Dredged/Excavated Sediment;
· ETWB TC(W) No. 19/2005, Environmental Management on Construction Sites;
· ETWM TC(W) No. 22/2003 and 22/2003A, Additional Measures to Improve Site Cleanliness and Control Mosquito Breeding on Construction Sites;
· ETWB TC(W) No. 33/2002, Management of Construction and Demolition Material Including Rock;
· Works Bureau TC No. 12/2002, Specification Facilitating the Use of Recycled Aggregates;
· Works Bureau TC Nos. 25/99, 25/99A and 25/99C, Incorporation of Information on Construction and Demolition Material Management in Public Works Sub-committee Papers; and
· Works Bureau TC No. 2/93, Public Dumps.
8.2.3. The Waste Disposal Ordinance (WDO) prohibits the unauthorized disposal of wastes. Construction waste is defined under Waste Disposal (Charges for Disposal of Construction Waste) Regulation 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. It is specified under the WDO that wastes can only be disposed of at designated waste disposal facilities (e.g. landfill, public fill, etc.) licensed by EPD. For construction work with a value of more than HK$1 million, the main contractor is required to establish a billing account at EPD prior to transporting any construction waste to the designated waste disposal facilities. The vessels for delivering construction waste to the public fill reception facilities require prior approval from the Public Fill Committee (PFC). Any violation to these regulations may lead to fine and/or imprisonment.
8.2.4. Land (Miscellaneous Provisions) Ordinance provides control on dumping at public fill. It is specified that the inert portion of construction waste (also called public fill) may be taken to public fill reception facilities which are operated by the Civil Engineering and Development Department (CEDD). The Ordinance requires dumping licenses to be obtained by individuals or companies who deliver inert C&D materials to public filling areas. The CEDD issues the licences under delegated powers from the Director of Lands. Under the licence conditions, public fill reception facilities will only accept inert earth, soil, sand, rock, boulder, rubble, brick, tile, concrete, asphalt, masonry or used bentonite. The PFC will advise on the acceptance criteria for disposal of inert C&D materials at public fill reception facilities in accordance with Development Bureau Technical Circular (Works) (TC(W)) No. 6/2010.
Chemical Waste
8.2.5. Chemical wastes may pose environmental, health and safety hazards. These hazards may include:
· Toxic effects to workers;
· Adverse effects on air quality, water quality and land contamination due to spillage;
· Hazards of fire; and
· Disruption of downstream sewage treatment works if the chemical waste enters the sewerage system.
8.2.6. Waste Disposal (Chemical Waste) (General) Regulations provides for control of all aspects of chemical waste disposal, including handling, storage, collection, transportation and disposal of waste. Chemical waste is defined by the Regulations as any substance or thing being scrap material, effluent, or an unwanted substance or by-product arising from the application of or in the course of any process or trade activity, and which is or contains any substance or chemical specified in the prescribed schedule if such substance or chemical occurs in such form, quantity or concentration so as to cause pollution and constitute danger to health or risk of pollution to the environment.
8.2.7. Under the regulations, all producers of chemical waste must register with EPD or else it will be an offence and is liable to fine and/or imprisonment. The regulations require waste producers to arrange proper packaging, labelling and storage of chemical waste before they are transported off-site to disposal facilities, in order to safeguard the health and safety of workers and the general public and to minimise potential hazards arising from improper handling of chemical waste. These requirements apply also to temporary storage of chemical waste prior to on-site or in-house treatment. Registered chemical waste producers must treat their waste at on-site plant licensed by EPD or by licensed waste collector to transport the wastes to a licensed facility.
8.3.1. The criteria and methodologies for assessing waste management implications from the handling, storage, collection, transportation and disposal of waste material generated from the proposed Project are outlined in Annex 7 and Annex 15 of the EIAO-TM respectively.
8.3.2. The waste management hierarchy has been applied in the assessment and development of mitigation measures for waste arising from the proposed Project. The waste management hierarchy is a concept which shows the desirability of various waste management methods and comprises the following in order of preference:
(a) Avoidance;
(b) Minimisation;
(c) Recycling/reuse;
(d) Treatment; and
(e) Disposal.
8.3.3. All opportunities for reducing waste generation have been assessed based upon the following factors:
· Avoiding or minimising waste generation throughout design, construction and operation phase;
·
Reusing and recycling C&D materials on site or other project; and
·
Adopting better management practices to promote sorting of C&D materials.
8.3.4. In accordance with Appendix E1 of the EIA Study Brief, the quantity, quality and timing of waste arising as a result of the construction and operation activities of the proposed Project and associated works have been estimated, based on their sequence and duration. Design, general layout, construction methods and programme to minimise the generation of public fill/inert C&D materials have been considered.
8.3.5. The assessment includes the following tasks:
· Estimation of the types and quantities of waste generated;
· Evaluation of potential impacts from the handling, storage, collection, transportation and disposal of waste; and
· Proposal of mitigation measures for waste management.
8.4.1. The construction activities to be carried out for construction of the proposed Project would generate a variety of wastes that can broadly be divided into distinct categories based on their composition and ultimate disposal methods. The identified waste types include:
· Construction and demolition (C&D) materials (including excavated materials);
· Construction and demolition (C&D) wastes;
· Chemical waste; and
· General refuse.
Construction and Demolition (C&D) Materials
8.4.2. Construction and demolition (C&D) materials that comprise inert materials, such as rock, rubble, boulder, earth, soil, sand, concrete, asphalt, brick, tile, masonry or used bentonite, should be reused on-site or as pubic fill as much as possible.
8.4.3. C&D materials will be minimised through careful planning during detailed design and good site practice during construction.
8.4.4. Since the Project site was formed by reclamation, levelling of land and excavation by cutting into slope will not be required for site formation. Also, underground basement floor is chosen to be excluded from the design of the proposed Project. Hence, majority of the C&D materials of the proposed Project will be from the construction of the building and associated structures.
8.4.5. Conventional steel-H piling is proposed as the piling method of the proposed Project, which in turn minimises the waste to be generated from excavation via drilling. Since deep excavation from piling works is not anticipated, no excavated sediment is expected to be generated.
8.4.6. The major source of C&D materials from the proposed Project will be excavated fill materials from topsoil and broken concrete from the removal of previously paved ground. Construction of 3m-deep pile caps, ground beams, underground utilities, etc. will lead to excavation of 21,018m3 topsoil. One quarter of which (5,254m3) is expected to be reused on site whereas the remaining 15,764m3 of which will be recycled at public fill bank. 2,102m3 of broken concrete will also be generated during site formation. The type and quantity of C&D materials that is anticipated to be diverted to public fill reception facilities during construction phase of the proposed Project is summarised in Table 8.1 below:
Table 8.1 Summary of C&D Materials Arising from the Proposed Project
|
Material
Type and Potential Sources |
Estimated Quantity |
Proposed Waste Management |
|
Excavated topsoil
for 3m-deep pile cap |
15,764m3 |
To be disposed of at public fill reception facilities |
|
5,254m3 |
To be reused on site with proper sorting |
|
|
Broken concrete
from the removal of previously paved ground with a depth of 0.3 m during
site formation |
2,102m3 |
To be disposed of
at public fill reception
facilities |
|
Total |
23,120m3 |
|
8.4.7. The inert C&D materials to be disposed of at public filling reception facilities shall be materials consisting of soil, concrete, etc. The materials shall be free from plastics, chemical waste, industrial metals and other materials that are considered as C&D wastes.
8.4.8. Two-third of excavated topsoil and broken concrete as mentioned in Table 8.1 are proposed to be delivered to the Tseung Kwan O Area 137 Fill Bank through the Chai Wan Public Fill Barging Point (PFBP) at 11 Ka Yip Street, Chai Wan, Hong Kong. Figure 8.1 shows the shortest transportation route from the Project site to the barging point. This route will be adopted by the dump trucks during construction period.
8.4.9. The transportation of C&D materials will be undertaken over a 29-month construction period. Given an average truck capacity of 7.5m3, approximately 2,380 dump trucks would be required throughout the construction period. As C&D materials are expected to be exported on a regular basis, a maximum of 4 trips per day is therefore anticipated. In view of the estimated number of dump trucks arising from transportation of C&D materials, the impacts from transportation off-site is expected to be limited.
8.4.10. The Project Proponent / Main Contractor should timely notify the estimated volumes of excavated materials to be generated and make agreement with the PFC on the disposal of inert C&D Materials. C&D Materials should be segregated from other wastes to avoid contamination and to ensure acceptability at public fill reception facilities and other construction sites.
8.4.11. All C&D materials will need to be carefully stockpiled if it cannot be reused or removed directly to avoid dust and other nuisance impacts. A designated temporary storage area of C&D materials must be provided on site. No construction work is allowed to proceed until all issues on management of C&D materials have been resolved and all relevant arrangements have been agreed between the responsible Government departments and contractors.
Construction and Demolition (C&D) Waste
8.4.12. Construction and Demolition (C&D) waste comprises non-inert materials, including mixture of topsoil and dead vegetative materials, timber, glass, steel and plastics, etc. arising from construction and demolition that are not suitable for backfilling.
8.4.13. The Contractor should separate C&D waste from inert C&D materials on-site. All segregated recyclable materials (e.g. metal) should be collected by reputable licensed recyclers. The remaining C&D waste will require disposal of at SENT Landfill through Island Eastern Corridor (IEC) by dump trucks.
8.4.14. The estimated quantity of C&D waste (e.g. timber formwork, maintenance and packaging waste, other construction debris, etc.) to be generated would be small and the quantity of which is expected to be 5,700m3, given careful design, planning, site management and control of ordering procedure.
8.4.15. Given an average truck capacity of 7.5m3, approximately 760 dump trucks would be undertaken over a 29-month construction period. As C&D waste is expected to be exported on a regular basis, a maximum of 2 trips per day is anticipated. In view of the estimated number of dump trucks arising from transportation of C&D waste, the impacts arising from increased traffic loading would be limited.
8.4.16. All C&D wastes will need to be carefully stockpiled to avoid dust and other nuisance. A designated temporary storage area of C&D wastes must be provided on site. No construction work is allowed to proceed until all issues on management of C&D wastes have been resolved and all relevant arrangements have been agreed between the responsible Government departments and contractors.
Chemical Waste
8.4.17. Chemical waste that is likely to arise from the construction activities for the proposed Project includes:
· Scrap batteries or acid / alkali from construction plant maintenance activities;
· Used paints, engine oils, hydraulic fluids and waste fuel;
· Spent mineral oils / cleansing fluids from machineries; and
· Spent solvent / solutions, some of which may be halogenated, from equipment cleansing activities.
8.4.18. The amount of chemical waste to be generated throughout construction phase is estimated to be approximately 100 L on average, depending on the degree of 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 during the construction of the proposed Project would be very small given the small scale of the proposed Project. Given that the chemical waste generated are to be handled, stored, transported and disposed of in an appropriate manner, impacts such as potential hazard and spillage will not be anticipated.
8.4.19. Nevertheless, the Contractor should register to the EPD as a Chemical Waste Producer in strict accordance with the Waste Disposal (Chemical Waste) (General) Regulation. Chemical waste has to be stored on-site with suitable containers so that leakage or spillage is prevented during the handling, storage, and subsequent transportation. The chemical waste should be collected by licensed collectors for subsequent disposal at licensed chemical waste disposal facilities, e.g. the Chemical Waste Treatment Centre (CWTC) at Tsing Yi or other licensed facilities by licensed collectors.
General Refuse
8.4.20. General refuse such as waste papers, plastic packaging, food wastes, etc. will be generated by the construction workforce during construction phase of the proposed Project.
8.4.21. Since no information regarding the number of on-site workers is available at this stage of the proposed Project, it has been assumed that a maximum of 100 workers will work simultaneously at the Project site during construction phase of the proposed Project. Quantity of general refuse to be generated per day is therefore estimated to be 65 kg (assuming a waste generation rate of 0.65 kg per person per day).
8.4.22. General refuse will have to be temporarily stored in enclosed bins or compaction units and will be collected on a regular basis. With proper on-site handling and storage as well as regular disposal of the wastes, no adverse impact is envisaged.
8.4.23. General refuse shall be stored in enclosed bins or compaction units separated from excavated and inert C&D materials to minimise odour nuisance. The Contractor shall employ a licensed waste collector to separate general refuse from C&D materials and remove general refuse from the site to WENT Landfill through Island East Refuse Transfer Station in Chai Wan.
General Refuse
8.4.24. The operation phase of the proposed Project involves office activities and vehicle repair / testing activities. The quantity of general refuse arising from the future operation of the proposed Project is expected to be insignificant.
Chemical Waste
8.4.25. The key concern of waste type arising from the operation of the proposed Project is expected to be chemical waste. Chemical waste from vehicle repair / testing activities, which includes scrap batteries, used engine oils, lubricating and hydraulic fluids and spent mineral oils / cleaning fluids from mechanical machinery are anticipated.
8.4.26. The type and quantity of chemical waste that is anticipated to arise from the operation of the proposed Project is summarised in Table 8.2 below. Other than the abovementioned chemical waste, oily substances will accumulate inside oil / petrol interceptors in the vehicle washing and repair / testing areas.
Table 8.2 Summary of Chemical Waste Arising from the Proposed Project
|
Chemical Type |
Estimated Quantity |
|
Used lubrication oil |
10,000 L/year |
|
Used batteries |
800 nos./year |
|
Non-halogenated solvents |
1,500 L/year |
|
Halogenated solvents |
700 L/year |
|
Acid waste |
3,400 L/year |
8.4.27. Provided that proper management procedures can be followed according to the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice of the Packaging, Labelling and Storage of Chemical Waste, significant impacts such as potential hazard and spillage would not be anticipated.
8.4.28. All chemical waste arising from the operation of the proposed Project will be regularly removed and transported away by licensed collectors for subsequent disposal of at Tsing Yi Chemical Waste Treatment Centre or other licensed chemical waste disposal facilities.
8.5.1. Adverse impact from waste management is not expected with the strict implementation of good site practices. Recommendations for good site practices during the construction activities include:
· The Contractor shall prepare a Waste Management Plan (WMP) in accordance with the requirements set out in the ETWB TCW No. 19/2005, Waste Management on Construction Site, for the Engineer's Representative approval. The WMP shall include monthly and yearly Waste Flow Tables that indicate the amounts of waste generated, recycled and disposed of (including final disposal site);
· The Contractor’s waste management practices and effectiveness shall be audited by the Engineer's Representative on regular basis;
· The Contractor shall provide training for site staff for the concept of site cleanliness and appropriate waste management procedures, including waste reduction, reuse and recycling;
· The Contractor shall ensure sufficient waste disposal points and regular collection of waste;
· The Contractor shall use trucks with covering for the open-box bed and enclosed container shall be used to minimise windblown litter and dust during transportation of waste; The Contractor shall implement regular cleaning and maintenance programme for drainage systems, pumps and oil interceptors;
· Separation of chemical wastes for special handling and appropriate treatment at a Chemical Waste Treatment Facility (CWTF);
· Encourage collection of aluminium cans, paper and plastic bottles by providing separate labelled bins to enable these wastes to be segregated from other general refuse generated by the workforce;
· 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;
· Wheel washing facilities shall be used by all trucks leaving the site to prevent transfer of mud onto public roads;
· Make provisions in contract documents to allow and promote the use of recycled aggregates where appropriate;
· No waste shall be burnt on-site;
· A recording system for the amount of wastes generated, recycled and disposed (including disposal sites) should be proposed;
· Plan and stock construction materials carefully to minimise amount of waste generated and avoid unnecessary generation of waste; and
· 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 form utilizing them. Night soil should be regularly collected by licensed collectors.
C&D Materials / Waste
·
Use standard formwork or pre-fabrication as far as practicable so as to
minimise the C&D Materials arising;
·
Consider the use of more durable formwork or plastic facing for
construction works;
·
Avoid the use of wooden hoardings and substitute with metal hoarding to facilitate
recycling;
·
Purchase of construction materials should be carefully planned in order
to avoid over-ordering and wastage;
·
Establish a trip-ticket system in accordance with DevB TC(W) No. 6/2010
and Waste Disposal (Charges for Disposal of Construction Waste) Regulation in
order to monitor the disposal of inert C&D Materials at public fill and the
remaining C&D Waste to landfills, and control fly-tipping;
· Design foundation works to minimise the amount of excavated material to be generated;
· Sort construction debris and excavated materials on-site to recover reusable/recyclable portions (i.e. soil, broken concrete, metal, etc.) for backfilling and reinstatement;
· Segregate and store different types of waste in different containers, skips or stockpiles to enhance reuse or recycling of materials and their proper disposal;
· Specify in design & build contract the use of recycled aggregates where appropriate;
· Plan and stock construction materials carefully to minimise the amount of waste to be generated and to avoid unnecessary generation of waste; and
· Recommend the use of metal fencing or building panels, which are more durable than wooden panels, for the erection of construction site hoarding.
Chemical Waste
· Chemical waste producers should be registered with the EPD;
· Chemical waste should be handled in accordance with the“Code of Practice on the Packaging, Handling and Storage of Chemical Wastes” including but not limited to the followings:
- Good quality containers compatible with the chemical wastes should be used and maintained in good conditions and securely closed, with incompatible chemicals be stored separately.
- Appropriate labels should be securely attached on each chemical waste container in English and Chinese according to the instructions prescribed in Schedule 2 of the Regulations.
- A licensed collector to transport and dispose of the chemical wastes should be employed by the Contractor, to either the Chemical Waste Treatment Centre at Tsing Yi, or any other licensed facilities.
· Waste oils, chemicals or solvents should not be discharged to drain; and
· Routine cleaning and maintenance programme for drainage systems, sumps and oil interceptors during operation.
General Refuse
· Sufficient dustbins should be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws;
· Sufficient enclosed bins should be provided for general refuse, food and beverage waste to reduce odour, pest and litter impacts;
· General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes;
· A reliable waste collector should be employed to clear general refuse from the construction site on a daily basis and disposed of to the licensed landfill or refuse transfer station;
· Office wastes can be reduced by recycling of paper if such volume is sufficiently large to warrant collection. Participation in a local collection scheme by the Contractor should be advocated; and
· Waste separation facilities for paper, aluminium cans, plastic bottles, etc. should be provided on-site and collected by individual collectors should be encouraged.
8.6.1. The proposed Project is likely to result in the generation of a variety of wastes and require management and disposal of C&D material, chemical waste and general refuse. However, the associated impacts are considered as temporary. Provided that different waste types are managed by implementing all the recommended measures, no unacceptable adverse environmental impacts arising from the handling, storage, transportation or disposal of the wastes generated by the proposed Project would be envisaged.
8.7.1. It is recommended that regular auditing by an Environmental Team should be carried out during the construction phase of the proposed Project to ensure waste are being managed with the appropriate procedures or practices in accordance to relevant legislation and waste management guidelines as well as those recommended in this EIA Report. The audits will examine all aspects of waste management including waste generation, storage, recycling, transport and disposal.
8.7.2. A WMP, as part of EMP, should be prepared in accordance with ETWB TC(W) No.19/2005 and submitted to the Project / Site Engineer for approval. The recommended mitigation measures should form the basis of the WMP. The monitoring and auditing requirement stated in ETWB TC(W) No.19/2005 should be followed with regard to the management of C&D Materials.
8.8.1. The type, quantity and timing for the generation of waste during the construction phase have been assessed.
8.8.2. Building form and construction methods to minimise waste generation are adopted. Recommendations have been made for the Contractor for implementation of measures during the construction period to minimise waste generation and any off-site disposal.
8.8.3. Provided that the recommendations set out in this section are properly implemented, adverse residual impact is not anticipated during the construction phase of the proposed Project.
8.8.4. The types and quantities of waste that will be generated during the operation phase have been assessed. Recommendations have been made to ensure proper handling, storage, collection, transportation and disposal of waste.
8.8.5. Provided that the recommendations set out in this section are properly implemented, adverse residual impact is not anticipated during the operation phase of the proposed Project.