5.
WASTE MANAGEMENT
5.1
Waste Management Measures during
Construction
5.1.1
The
HKSAR Government's construction and demolition waste management policy follows
the same hierarchy as for other wastes, i.e. in order of desirability:
avoidance, minimisation, recycling, treatment and safe disposal of waste. During the construction period the Contractor, Engineer and
environmental specialists (Environmental Team, Independent Environmental Check)
should work closely together with a view to reduce the volumes of materials requiring
removal and final disposal.
5.1.2 Upon appointment, the main Contractor of each construction contract should prepare and implement an Environmental Management Plan (EMP) in accordance with ETWB TCW No. 19/2005 – “Environmental Management on Construction Sites” which should describe the arrangements for avoidance, reuse, recovery, recycling, storage, collection, treatment and disposal of different categories of waste to be generated from the construction activities. The EMP should incorporate site specific factors, such as the designation of areas for segregation and temporary storage of reusable and recyclable materials. The EMP should be submitted to the Engineer for approval. The Contractor should implement the waste management practices in the EMP throughout the construction stage of the Project. The EMP should be reviewed regularly and updated (preferably monthly) by the Contractor. The EMP should take into account the recommended mitigation measures in the approved EIA Report.
5.1.3 The Contractor should refer to the simplified Construction and Demolition Material Management Plan (C&DMMP) conducted for this Project (Appendix 6.2 of the EIA) to facilitate him in the preparation of the EMP. The simplified C&DMMP has been endorsed by CEDD’s Vetting Committee and approved by the Public Fill Committee (PFC). CEDD’s Vetting Committee will monitor the implementation of the C&DMMP and report to Public Fill Committee in accordance with ETWB TCW No. 33/2002 during construction.
5.1.4 Training of construction staff should be undertaken by the Contractor about the concept of site cleanliness and appropriate waste management procedures. The Contractor should develop and provide toolbox talk for on-site sorting of C&D materials to enhance worker’s awareness in handling, sorting, reuse and recycling of C&D materials. Requirements for staff training should be included in the EMP.
5.1.5 Good planning and site management practice should be employed to eliminate over ordering or mixing of construction materials to reduce wastage. Proper storage and site practices will minimise the damage or contamination of construction materials. Regular cleaning and maintenance of the waste storage area should be provided.
5.1.6 Where waste generation is unavoidable, the potential for recycling or reuse should be rigorously explored. If waste cannot be recycled, disposal routes described in the EMP should be followed. A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be implemented. In order to monitor the disposal of C&D material and solid wastes at public fill reception facilities and landfills and to control fly-tipping, a trip-ticket system should be included. One may make reference to ETWB TCW No. 31/2004 for details.
5.1.7 Imported soft fill and rocks should be source from CEDD’s fill bank, other projects or other approved sources instead of using new materials. Approval from the Engineer and all other relevant parties should be obtained by the Contractor before importation of the fill materials.
On-site Sorting,
Reuse and Recycling
5.1.8 All waste materials should be segregated into categories covering:
· excavated materials suitable for reuse on-site;
· excavated materials suitable for public filling facilities;
· remaining C&D waste for landfill;
· chemical waste; and
· general refuse for landfill.
5.1.9 Proper segregation and disposal of construction waste should be implemented. Separate containers should be provided for inert and non-inert wastes.
5.1.10 Sorting is important to recover materials for reuse and recycling. Specific area should be allocated for on-site sorting of C&D materials and to provide a temporary storage area for those sorted materials such as metals, concrete, timber, plastics, glass, excavated spoils, bricks / tiles and waste papers. If area is limited, all C&D materials should at least be sorted on-site into inert and non-inert components. Non-inert materials (C&D waste) such as bamboo, timber, vegetation, packaging waste and other organic materials should be reused and recycled wherever possible and disposed of to designated landfill only as a last resort. Inert materials (public fill) such as concrete, stone, clay, brick, soil, asphalt and the like should be separated and reused in this or other projects (subject to approval by the relevant parties in accordance with the ETWB TCW No. 31/2004) before disposed of at a public fill reception facility operated by Civil Engineering and Development Department (CEDD). Steel and other metals should be recovered from demolition waste stream and recycled.
5.1.11 The reuse of inert materials such as soil, rock and broken concrete should be maximised. Waste should be separated into fine, soft and hard materials. With the use of a crusher coarse material can be crushed to make it suitable for use as fill material where fill is required in the works. This minimises the use of imported material and maximises use of the C&D material produced.
5.1.12 Prior to export of material from the site, the potential for it to be reused should be assessed. Most C&D material can easily be reused with minimum processing. Waste separation methods should be followed to ensure that C&D waste is separated at source. Suitable soft materials should be used for landscaping and grading of embankments. Fine material should be separated out and used as topsoil.
5.1.13 The feasibility of using recycled aggregates in lieu of virgin materials should be rigorously considered during the detailed design and construction phases as stipulated in WBTC No. 12/2002 and ETWB TCW No. 24/2004. In general, recycled aggregates are suitable for use as fill materials in earthworks, road sub-base formation, and drainage works. Recycled aggregates can also be used in concrete (up to Grade 35) for mass concrete walls and other minor structures such as planter boxes, toe wall planters and pavement, etc.
5.1.14 Recycled inert C&D material should be used in the works as sub-bases for access roads and footpaths of the proposed channel. Recycled aggregates should be considered for use in concrete as outlined in the above mentioned technical circulars. Some recycled rock material can be reused as rock fill or as stream bed material. This is dependent on size of rock fragments but can be achieved by appropriate use of a crusher.
Site Clearance /
Demolition Materials
Excavated
Materials
5.1.15 All C&D materials should be sorted on-site into inert and non-inert components by the Contractor. Non inert materials (C&D waste) such as wood, glass and plastic should be reused and recycled before disposal to a designated landfill as a last resort (currently assume to be the WENT Landfill). Inert materials (public fill) such as soil, rubble, sand, rock, brick and concrete should be separated and where appropriate broken down to size suitable for subsequent filling. Suitable C&D material should be use as pipe bedding or for backfilling of retaining walls, box culvert and formation of channel embankments. Excavated rocks from existing streams should be reused for rip-rap lining. Inert materials should be reused on-site or in other projects approved by relevant parties in accordance with the ETWB TCW No. 31/2004 before disposed of at public fill reception facilities. Steel and other metals should be recovered from C&D materials and recycled.
5.1.16 Some of the excavated sediment from the stream bed will be contaminated with high levels of heavy metals. Contaminated sediment should be disposed of in accordance with ETWB TCW No. 34/2002 and WBTC No. 12/2000. In order to minimise off-site disposal, uncontaminated sediment should be reused as channel bed material as far as possible.
5.1.17 Good quality reusable topsoil should be stockpiled for later landscaping works. Stockpiles should be less than 2 m in height, formed to a safe angle of repose and hydroseeded or covered with tarpaulin to prevent erosion during the rainy season and to minimise dust generation.
5.1.18 Control measures for temporary stockpiles on-site should be taken in order to minimize the noise, generation of dust, pollution of water and visual impact. These measures include:
· surface of stockpiled soil should be regularly wetted with water especially during dry season;
· disturbance of stockpiled soil should be minimized;
· stockpiled soil should be properly covered with tarpaulin especially when heavy rain storms are predicted;
· stockpiling areas should be enclosed where space is available;
· stockpiling location should be away from the water bodies; and
· an independent surface water drainage system equipped with silt traps should be installed at the stockpiling area.
5.1.19
The identification of final
disposal sites for C&D materials generated by the construction works will
be considered during the detailed design stage of the Project when the volume
and types of C&D materials can be more accurately estimated. The Public
Fill Committee of CEDD should be consulted on designated outlets (e.g. public
fill reception facility) for public fill, whilst
5.1.20 In order to avoid dust or odour impacts, any vehicles leaving a works area carrying C&D waste or public fill should have their load covered up before leaving the construction site.
5.1.21 C&D materials should be disposed of at designated public fill reception facilities or landfills. Reuse of public fill materials at other construction projects is subject to the approval of the relevant project proponents, Engineer and/or other relevant authorities, such as LandsD, PlanD, etc. Furthermore, unauthorized disposal of C&D materials in particular on private agricultural land is prohibited and may be subject to relevant enforcement and regulating actions. The Contractor shall refer and strictly follow the trip-ticket system for the disposal of C&D materials as stipulated in the ETWB TCW No. 31/2004.
Chemical Waste
5.1.22 Where the construction processes produce chemical waste, the Contractor must register with EPD as a chemical waste producer. Wastes classified as chemical wastes are listed in the Waste Disposal (Chemical Waste) (General) Regulation. These wastes are subject to stringent disposal routes. EPD requires information on the particulars of the waste generation processes including the types of waste produced, their location, quantities and generation rates. A nominated contact person must be registered with EPD. An updated list of licensed chemical waste collector can be obtained from EPD.
5.1.23 Storage, handling, transport and disposal of chemical waste should be arranged in accordance with the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes published by EPD, and should be collected by a licensed chemical waste collector.
5.1.24
Suitable containers should be
used for specific types of chemical wastes, containers should be properly labelled
(English and Chinese in accordance with instructions prescribed in Schedule 2
of the Regulations), resistance to corrosion, safely stored and securely closed.
Stored volume should not be kept more than 450 liters unless the specification
has been approved by the
5.1.25 Hard standing, impermeable surfaces draining via oil interceptors should be provided in works area compounds. Interceptors should be regularly emptied to prevent release of oils and grease into the surface water drainage system after accidental spillages. The interceptor should have a bypass to prevent flushing during periods of heavy rain. Oil and fuel bunkers should be bunded and/or enclosed on three sides to prevent discharge due to accidental spillages or breaches of tanks. Bunding should be of sufficient capacity to accommodate 110% of the volume of the largest container or 20% of the total volume of waste, whichever is largest. Waste collected from any grease traps should be collected and disposed of by a licensed contractor.
5.1.26 Lubricants, waste oils and other chemical wastes are likely to be generated during the maintenance of vehicles and mechanical equipment. Used lubricants should be collected and stored in individual containers which are fully labelled in English and Chinese and stored in a designated secure place. If possible, such waste should be sent to oil recycling companies, and the empty oil drums collected by appropriate companies for reuse or refill.
5.1.27 The registered chemical waste producer (i.e. the contractor) has to arrange for the chemical waste to be collected by licensed collectors. The licensed collector should regularly take chemical waste to a licensed chemical waste treatment facility (such as the Chemical Waste Treatment Centre in Tsing Yi). A trip ticket system operates to control the movement of chemical wastes.
5.1.28 No lubricants, oils, solvents or paint products should be allowed to discharge into water courses, either by direct discharge, or as contaminants carried in surface water runoff from the construction site.
General Works
Waste
Concrete Waste
5.1.29 Dry concrete waste (considered as public fill) should be sorted out from the other wastes and recycled for reuse or sorted out for disposal at designated public fill reception facilities.
Wooden Materials
5.1.30 All wooden materials used on-site should be kept separate from other wastes to avoid damage and to facilitate reuse. Timber which cannot be reused should be sorted out from other waste and stored separately from all inert waste before being disposed of to landfill.
5.1.31 Reusable steel or concrete panel shutters, fencing and hoarding and signboard should be used as a preferred alternative to items made of wood, to minimise wastage of wood. Attention should be paid to WBTC No. 19/2001 – “Metallic Site Hoardings and Signboards” to reduce the amount of timber used on construction sites. Metallic alternatives to timber are readily available and should be used rather than new timber. Precast concrete units should be adopted wherever feasible to minimize the use of timber formwork.
5.1.32 Only waste material need to be taken to a landfill. It should be separated from recyclable wood and steel materials. As for all waste types these materials should be reused on-site or other approved sites before disposal is considered as an option. Disposal to landfill should only be considered as a final option. Contractors are responsible for storage of re-useable materials on-site.
Municipal Waste
5.1.33 General refuse generated on-site should be stored in enclosed bins or skips and collected separately from other construction and chemical wastes and disposed of at designated landfill. A temporary refuse collection point should be set up by the Contractor to facilitate the collection of refuse by licensed contractors. The removal of waste from the site should be arranged on a daily or at least on every second day by the Contractor to minimise any potential odour impacts, minimise the presence of pests, vermin and other scavengers and prevent unsightly accumulation of waste.
5.1.34 The recyclable component of the municipal waste generated by the workforce, such as aluminium cans, paper and cleansed plastic containers should be separated from other waste. Provision and collection of recycling bins for different types of recyclable waste should be set up by the Contractor. The contractor should also be responsible for arranging recycling companies to collect these materials.
5.1.35 The burning of refuse on-site is prohibited under the Air Pollution Control Ordinance (APCO) (Cap.311).
5.2.1 The implementation schedule of the recommended mitigation measures is presented in Appendix A.
5.2.2
During
the site inspections and the document review procedures as mentioned in this
manual, the ET shall pay special attention to the issues relating to waste
management, and check whether the Contractor has implemented the recommended
mitigation measures.
5.2.3
Auditing should be carried out
periodically to determine if waste is being managed in accordance with
prescribed waste management procedures and the EMP. The audits should examine
all aspects of waste management including waste generation, storage, recycling,
treatment, transportation, and disposal. The general site inspections including
waste management issues will be undertaken weekly by the ET to check all
construction activities for compliance with all appropriate environmental
protection and pollution control measures, including those set up in the EMP.
Meanwhile, waste management audit will also be carried out as part of the monthly
audit by the IEC.
5.3
Waste Management Measures during
Operation
5.3.1
Adequate litter bins should be provided
at the viewing point and carpark and should be regularly emptied by Food and
Environmental Hygiene Department (FEHD). Normal road sweeping and street
cleansing routinely carried out by FEHD on a need basis is considered adequate
to minimise impact from such waste. Road side gullies should be cleared and
desilted regularly to ensure proper operation of the road drainage system.
5.3.2
In general, desilting or
maintenance works should be carried out during dry season where flow in the watercourse
is low. Non-inert materials such as excess vegetation and garbage should be
properly packed and disposed of to landfill. Inert material such as excess silt
should be dried and disposed of public fill reception facilities or to landfill
if the amount is negligible. The locations for the disposal of the above
materials should be identified and agreement sought with the relevant
departments before commencement of the maintenance works.