8.1.1 Summary of Waste Arisings
8.1.1.1 The Contractor is responsible for waste control within the construction site, removal of waste material produced from the site and to implement any mitigation measures to minimise waste or redress problems arising from the waste from the site. Activities during the construction phase will result in the generation of a variety of wastes which can broadly be classified into distinct categories based on their nature and the options for their disposal. These include:
· Marine dredged sediment;
· Excavated construction and demolition (C&D) materials suitable for public fill, including the alluvium from the tunnel construction;
· Construction and demolition waste, including cleared vegetation, which is not suitable for public fill;
· Chemical waste;
· Sewage; and
· General refuse.
8.1.1.2 Marine dredged sediment represents the largest quantity of material to be generated by the project, although the use of both non-dredged and fully dredged methods for the construction of the southern and northern tunnel landfall reclamations have been considered in order to minimize the amounts of material generated where possible.
8.1.1.3 In order to determine the nature of the sediment to be excavated, a marine ground investigation (GI) including sediment sampling and laboratory testing has been undertaken, in accordance with the requirements in ETWB TC(W) No.34/2002. In summary, two classifications of sediment material where identified, comprising Category L and Category M, that passes the biological testing (Mp) and the material is suitable for disposal in Type 1 open sea and Type 1 Open Sea (Dedicated) disposal.
8.1.1.4 A total of 5.24Mm3 of dredged material is predicted to be generated. It is proposed to dispose of all the Category Mp (0.73Mm3) and about 68% of the Category L material (3.05Mm3) to China, with the remaining Category L (1.46Mm3) being proposed to be disposed of in a Type I Open Sea Disposal site in Hong Kong.
8.1.1.5 The Construction and Demolition (C&D) materials generated from the TM-CLKL project will comprise the following:
· Alluvium and CDG from the submarine tunnel and deep sections of the marine viaduct bridge piers and building foundations;
· Excavation of reclamation materials for cut and cover tunnel, portal and ventilation building;
· Surplus surcharge from the reclamation works;
· Excavation materials from the land viaduct construction, slope cutting, utility diversions, site formation of the toll plaza and administration buildings formation; and
· Road and pavement demolition waste from the modification of the existing roads for new roads connections.
8.1.1.6 In accordance with the waste hierarchy, the amounts of materials to be generated has been minimised by optimizing the tunnel and slope profiles. However, a total of 2.85Mm3 of soft C&D material (generated from TBM submerged tunnel, deep marine viaduct foundations and removal of material for the cut and cover tunnel, portal and ventilation buildings at the landfalls) and 1.17Mm3 of materials generated from removal of surcharge at landfalls will be generated and will require off site disposal. However, all the material will be suitable for public fill, although alluvium and small amounts of CDG generated by the TBM tunnelling and deeper sections of the marine viaduct piles, will require to be treated at a slurry treatment plant and suitably dried before transfer to a fill bank. The by- product of the treatment comprises both a coarser, dry material and a wet spoil, and, where required, the spoil material shall be scarified to ensure it is "suitably" dried before it can be disposed of to the fill bank. This principle of disposal has been agreed by the Public Fill Committee.
8.1.1.7 Some 0.59Mm3 of C&D materials, from slope works and road pavement removal will be reused on site. In addition, 12.47Mm3 of various new material will, also, required importing. The onsite transfer and off site removal of the material has the potential for impacting any local residents associated with the possible dust generation from the exported fill, deposition of material on public roads and emissions and noise from the construction vehicles. However, the additional traffic is not expected to cause any additional impacts to sensitive receivers along this route.
8.1.1.8 The volumes C&D waste, are expected to be limited but the material, not being suitable for public fill, will require disposal to landfill. It is, also, unlikely that any large quantities of chemical wastes will be generated during the construction of this project but any materials should be handled, stored, transported and disposed of in an appropriate manner. Other wastes including sewage and general refuse will be generated and these will also need to be collected and disposed offsite appropriately.
8.1.2 Mitigation Measures
8.1.2.1 Based on the mitigation measures recommended in the EIA Report, the following measures, as summarized in the Environmental Mitigation Implementation Schedule in Appendix A, shall be undertaken when handling waste material during construction phase:
(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 Contractor as appropriate.
(ii) The TM-CLKL 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 below 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 ETWB(W) 31/2004 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 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 Public Fill Committee 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 TM-CLKL 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 slopes and road pavement will be reused for construction of the raised platform for the toll plaza.
(ix) C&D materials generated by construction of cut slopes along NLH at North Lantau shall be reused in reclamation works where possible.
(x) The surplus surcharge should be transferred to a fill bank.
(xi) TMB generated alluvium and CDG material should be treated at a slurry treatment plant prior to transfer to a fill bank.
(xii) Rock armour from the existing seawall should be reused on the new sloping seawall as far as possible.
(xiii) The site and surroundings shall be kept tidy and litter free.
(xiv) No waste shall be burnt on site.
(xv) Make provisions in contract documents to allow and promote the use of recycled aggregates where appropriate.
(xvi) Prohibit the Contractor to dispose of C&D materials at any sensitive locations e.g. natural habitat,, etc. The Contractor should propose the final disposal sites in the EMP and WMP for approval before implementation.
(xvii) Stockpiled material shall be covered by tarpaulin and /or watered as appropriate to prevent windblown dust and surface run off.
(xviii) Excavated material in trucks shall be covered by tarpaulins to reduce the potential for spillage and dust generation.
(xix) Wheel washing facilities shall be used by all trucks leaving the site to prevent transfer of mud onto public roads.
(xx) Dredged marine mud shall be disposed of in a gazetted marine disposal ground under the requirements of the Dumping at Seas Ordinance.
(xxi) Standard formwork or pre-fabrication should be used as far as practicable so as 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.
(xxii) The Contractor should recycle as many C&D materials (this is a waste section) 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.
(xxiii) All falsework will be steel instead of wood.
(xxiv) Chemical waste producers should register with the EPD. 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.
(xxv) Waste oils, chemicals or solvents shall not be disposed of to drain;
(xxvi) 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.
(xxvii) General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes. Sufficient dustbins shall be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws. In addition, general refuse shall be cleared daily and shall be disposed of to the nearest licensed landfill or refuse transfer station. Burning of refuse on construction sites is prohibited.
(xxviii) All waste containers shall be in a secure area on hardstanding;
(xxix) Aluminum cans are usually collected and recovered from the waste stream by individual collectors if they are segregated and easily accessible. Separately labelled bins for their deposition should be provided as far as practicable.
(xxx) Office wastes can be reduced by recycling of paper if such volume is sufficiently large to warrant collection. Participation in a local collection scheme by the Contractor should be advocated. Waste separation facilities for paper, aluminum cans, plastic bottles, etc should be provided on-site.
(xxxi) Training shall be provided to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling.
8.1.3 Waste Disposal Recommendations
8.1.3.1 The recommended disposal sites for the different types of waste are detailed in Table 8.1 below:
Table 8.1 Recommended Waste Disposal Sites
|
Type of Waste |
Disposal Site |
|
Marine Dredged Mud |
All Category Mp and a portion of Category L material to Open Sea or Open Seas Dedicated sites in Mainland China.
Remaining Category L materials to Ninepins or South of Cheung Chau(1) |
|
C&D materials |
Tuen Mun Areas 38 public fill bank |
|
C&D waste (plastics, glass, wood, including cleared vegetation etc.) |
North Lantau Refuse Transfer Station; or NWNT Refuse Transfer Station |
|
Chemical waste (as defined under Schedule 1 of the Waste Disposal (Chemical Waste) Regulation) |
Chemical Treatment Facility at Tsing Yi: or Other approved facility |
|
General refuse |
North Lantau Refuse Transfer Station; or NWNT Refuse Transfer Station |
Note (1) Subject to DASO application
8.2.1.1 The results of the contaminated land assessment did not reveal any contamination hotspots that might be affected by the proposed TM-CLKL works and as such no mitigation measures in the form of contaminated land remediation is required. Therefore, no EM&A activities for the construction nor operational phases have been recommended as no significant impacts are predicted.
8.3.1.1 EM&A requirements are required for waste management during the construction phase only and the effective management of waste arisings during the construction phase will be monitored through the site audit programme. The aims of the waste audit are:
· to ensure the waste arising from the works are handled, stored, collected, transferred and disposed of in an environmentally acceptable manner; and
· to encourage the reuse and recycling of material.
8.3.1.2 The Contractor shall be required to pay attention to the environmental standard and guidelines and carry out appropriate waste management and obtain the relevant licence/permits for waste disposal. The Environmental Team (ET) shall ensure that the Contractor has obtained from the appropriate authorities the necessary waste disposal permits or licences including:
· Chemical Waste Permits/licenses under the Waste Disposal Ordinance (Cap 354);
· Public Dumping Licence under the Land (Miscellaneous Provisions) Ordinance (Cap 28);
· Marine Dumping Permit under the Dumping at Sea Ordinance (Cap 466); and
· Effluent Discharge Licence under the Water Pollution Control Ordinance.
8.3.1.3 The Contractor shall refer to the relevant booklets issued by the DEP when applying for the licence/permit and the Environmental Team (ET) (see Section 1) shall refer to these booklets for auditing purposes.
8.3.1.4 During the site inspections and the document review procedures as mentioned in Chapter 10 of this Manual, the ET shall pay special attention to the issues relating to waste management and check whether the Contractor has followed the relevant contract specifications and the procedures specified under the laws of Hong Kong. In addition to the site inspections, the ET shall review the documentation procedures prepared by the Waste Coordinator once a week to ensure proper records are being maintained and procedures undertaken in accordance with the Waste Management Plan.
8.3.1.5 The Contractor’s waste management practices should be audited with reference to the checklist detailed in Table 8.2 below:
Table 8.2 Waste Management Checklist
|
Activities |
Timing |
Monitoring Frequency |
If non-compliance, Action Required |
|
All necessary waste disposal permits or licences have been obtained |
Before the commencement of demolition works |
Once |
Apply for the necessary permits/ licences prior to disposal of the waste. The ET shall ensure that corrective action has been taken. |
|
Only licensed waste haulier are used for waste collection. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to use a licensed waste haulier. The Contractor shall temporarily suspend waste collection of that particular waste until a licensed waste haulier is used. Corrective action shall be undertaken within 48 hours. |
|
Records of quantities of wastes generated, recycled and disposed are properly kept. For demolition material/waste, the number of loads for each day shall be recorded (quantity of waste can then be estimated based on average truck load. Should landfill charging be implemented, the receipts of the charge could be used for estimating the quantity). |
Throughout the works |
Weekly |
The Contractor shall estimate the missing data based on previous records and the activities carried out. The ET shall audit the results and forward to the ER and IEC for approval. |
|
Wastes are removed from site in a timely manner. General refuse is collected on a daily basis. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to remove waste accordingly. |
|
Waste storage areas are properly cleaned and do not cause windblown litter and dust nuisance. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to clean the storage area and/or cover the waste. |
|
Different types of waste are segregated in different containers or skip to enhance recycling of material and proper disposal of waste. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to provide separate skips/ containers. The Contractor shall ensure the workers place the waste in the appropriate containers. |
|
Chemical wastes are stored, handled and disposed of in accordance with the Code of Practice on the Packaging, Handling and Storage of Chemical Wastes, published by the EPD. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to rectify the problems immediately. Warning shall be given to the Contractor if corrective actions are not taken within 24 hrs and the Waste Control Group of the EPD shall be identified. |
|
Demolition material/waste in dump trucks are properly covered before leaving the site. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall instruct the Contractor to comply. The Contractor shall prevent trucks shall leaving the site until the waste are properly covered. |
|
Wastes are disposal of at licensed sites. |
Throughout the works |
Weekly |
The ET shall inform the ER and IEC of the non-compliance. The ER shall warn the Contractor and instruct the Contractor to ensure the wastes are disposed of at the licensed sites. Should it involve chemical waste, the Waste Control Group of EPD shall be notified. |
Note: ET – Environmental Team, IEC – Independent Environmental Checker, ER – Engineer’s Representative