5. WASTE MANAGEMENT
5.1.1 This section sets out measures that should be taken to avoid or minimize potential adverse impacts from construction waste of the Project. The main contractors should act as the overall coordinator for the management of waste and follow the requirement of Waste Management Plan (WMP) as described in the EIA. This is to ensure that the recommendations and site-specific factors such as the designation of areas for the segregation and temporary storage of reusable and recyclable materials are to be implemented. This WMP should be submitted to the Engineer for approval.
5.1.2 A proper Waste Management Plan targeting the followings to be implemented to ensure that wastes are adequately managed:
(i) waste identification;
(ii) waste minimization at source;
(iii) waste reuse & recycle;
(iv) waste segregation; and
(v) waste collection and disposal.
5.1.3 The various waste management options can be categorized
in terms of preference from an environmental viewpoint. The preferred options
have least impact and are more sustainable in the longer term. Hence, the
following waste management hierarchy is recommended:
· Avoidance and minimization, i.e. not generating waste through improving practices and design.
· Reuse of materials, thus avoiding disposal (generally with only limited reprocessing).
· Recovery and recycling, thus also avoiding disposal (although reprocessing may be required).
· Treatment and disposal, according to relevant laws, guidelines and proper practices.
5.1.4 This hierarchy should be used to evaluate waste management options, thus allowing maximum waste reduction and reduced costs. Waste reduction measures should be introduced at the design stage and carried through the construction activities, wherever possible, by careful purchasing control, reuse of formwork and proper site management. By reducing or eliminating over-ordering of construction materials, waste generation is avoided, and costs are reduced both in terms of purchasing of raw materials and disposal of waste.
5.1.5 In particular, all waste materials shall be segregated
into categories as follows:
· Inert portion of construction & demolition material (C&DM) for reuse on-site
· Inert portion of C&DM to be used as public fill
· Remaining C&D waste for landfill
· Chemical waste
· General refuse
5.1.6 Training and instruction of construction staff should be given at the site to increase awareness and draw attention to waste management issues and the need to minimize waste generation. The training requirement should be included in the site Waste Management Plan.
5.1.7 On-site measures promoting proper segregation and disposal of construction waste should be implemented. These measures may include the provision of separate containers for inert (rubble, sand, stone, etc.) and non-inert (wood, organics, etc.) wastes. The inert waste should be re-used on site before being disposed of at public filling area, and the non-inert waste should be sorted for re-use or recycling before being transported to landfills.
5.1.8 Where waste generation is unavoidable, the potential for recycling or reuse should be explored and opportunities taken. If wastes cannot be recycled, disposal routes described in the WMP should be followed.
5.1.9 Training shall be provided to workers on the concepts of the site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling.
5.1.10 Regular maintenance and cleaning of the waste storage areas shall be undertaken.
5.2 Measures to be Undertaken During Planning & Design Stages
5.2.1 Requirements for standard design section of viaduct decks, piers and pile caps will be adopted to encourage the use of steel formwork, Waste Management Plan and proper sorting, re-use and recycling of the waste shall be incorporated into the construction contracts.
5.2.2 Areas within the construction site shall be provided to allow for sorting and segregation of waste.
5.3 Measures to be Undertaken During the Construction Stage to Manage the Handling and Disposal of Waste
5.3.1 To monitor the proper disposal of solid waste at landfills and public fill at public filling facilities, a trip-ticket system on all solid waste transfer/disposal operations should be included as one of the contractual requirements (as described in WBTC No. 5/99, which will be replaced by ETWBTC No. 21/2002 in September 2002). The Independent Environmental Checker (IEC) should be responsible for auditing this system.
5.3.2 A record system documenting the amount of wastes generated, recycled and disposed; as well as disposal methods and sites should be implemented during the construction phase and audited by the IEC.
Storage, Collection and Transport of Waste
5.3.3 Licensed waste haulers should be employed to collect and
transport waste to the appropriate disposal points. The following measures to
minimize adverse impacts should be implemented:
· Handle and store waste in a manner which ensures that it is held securely without loss or leakage, thereby minimizing the potential for pollution;
· Use waste haulers authorized or licensed to collect specific categories of waste;
· Remove waste in a timely manner;
· Maintain and clean waste storage areas regularly;
· Minimize windblown litter and dust during transportation by either covering trucks or transporting waste in enclosed containers;
· Obtain the necessary waste disposal permits from the appropriate authorities, if they are required, in accordance with the Waste Disposal Ordinance (Cap 354), Waste Disposal (Chemical Waste) (General) Regulation (Cap 354), and the Land (Miscellaneous Provision) Ordinance (Cap 28);
· Dispose of waste at licensed waste disposal facilities;
· Develop procedures such as a ticketing system to facilitate tracking of loads, particularly for chemical waste, and to ensure that illegal disposal of waste does not occur; and
· Maintain records of the quantities of waste generated, recycled and disposed.
Handling and Disposal of Waste
Marine Dredged Sediment
5.3.4 Marine dredged sediment from pier sites with approximately 34,500m3 (uncontaminated sediment) should adopt open sea disposal at the South Cheung Chau spoil disposal area or the East Ninepins spoils disposal ground for uncontaminated sediment
5.3.5 Marine dredged sediment from pier sites with approximately 22,500m3 (contaminated sediment) should adopt confined marine disposal at East Sha Chau mud pits.
5.3.6 Stockpiling of dredged sediment would be avoided as far as possible and the dredged sediment would be disposed of shortly after removal from the pier site. Temporary holding of the dredged sediment in barge may be required. Release of sediment or contaminant from the barge is unlikely through implementation of recommended mitigation measures and management control of work.
5.3.7 Sediment dredged from the inlet channel and the proposed access route at Mai Po for enhancement measure with approximately 8,800m3 of Category M and Category H material with contaminant level <10xLCEL (contaminated sediment) could adopt confined marine disposal at East Sha Chu mud pits.
5.3.8 Licensed vessels should be employed for disposal of marine dredged sediment in accordance with relevant Port and Shipping Regulations.
5.3.9 Excavated materials may need to be temporarily stockpiled on-site. Control measures should be taken at the stockpiling area to prevent the generation of dust and pollution of water. Key control measures are highlighted below:
· Surface of stockpiled soil should be wetted with water when
necessary especially during dry season.
· Stockpiled soil should be properly covered with tarpaulins.
· Disturbance of stockpiled soil should be minimized.
· Stockpiling areas should be enclosed if possible.
Water Quality Control
· An independent surface water drainage system equipped with
silt traps should be installed at the stockpiling area.
· Stockpiled soil should be properly covered with tarpaulins during heavy rainstorms.
· Stockpiles of excavated materials should be placed in the location away from the shoreline.
5.3.10 Excavated material should be reuse/recycle wherever possible, or else, they should be disposed of at public fill area.
5.3.11 In order to minimize waste generation and to keep the associated environmental impacts within acceptable levels, the following control measures should be adopted.
5.3.12 Careful design, planning and good site management can minimize over-ordering and generation of waste materials such as concrete, mortar and cement grouts. The design of formwork should maximize the use of standard wooden panels so that a high level of reuse can be achieved. Alternatives such as steel formwork or plastic facing should also be considered to increase the potential for reuse.
5.3.13 The contractor should recycle as much of the C&DM as possible on-site. Proper segregation of waste types on site will increase the feasibility of certain components of the waste stream by recycling companies. For example, concrete and masonry can be used as general fill, and rebars can be sold to steel mills. Different areas of the worksite should be designated for such segregation and storage wherever site conditions permit.
5.3.14 All C&DM should be sorted on site into inert and non-inert components. Non-inert materials (C&D waste) such as wood, glass and plastic with not more than 30% by weight of inert material are acceptable for disposal to a landfill, probably WENT. C&D wastes with more than 30% inert material (by weight) should not be disposed of at landfills. However, the Waste Reduction Framework Plan (WRFP) aims to reducing this figure to less than 20%. Inert materials (public fill) such as soil, rubble, sand, rock, brick and concrete should be separated and broken down to size suitable for subsequent filling. Steel and other metals should be recovered from the C&DM and recycled as far as practical if possible.
5.3.15 C&D material should be disposed of at public fill area/landfill/contaminated disposal area depending on the quality of C&D waste.
5.3.16 The handling and disposal of bentonite slurries, if any is used, should be undertaken in accordance within ProPECC PN 1/94 on construction site drainage.
5.3.17 In order to avoid dust or odour impacts, vehicles leaving the work site carrying C&D wastes or public fill should have their load covered. Vehicles should be routed as far from sensitive receivers in the area as possible.
5.3.18 Effective from 1 July 1999, the Contractor must comply
with the trip-ticket system for the disposal of C&DM (WBTC No. 5/99, which
will be replaced by WBTC 21/2002 in September 2002). Confirmation has to be
sought from the Public Fill Committee (PFC) and EPD regarding the availability
of public filling facilities or a landfill, for inert C&D waste and
non-inert C&D waste, respectively.
5.3.19 Particular Specification for the construction contract of the Project shall include the following clauses with terminology as defined under WBTC No. 4/98:
· The Contractor shall produce a Construction and Demolition
Material Disposal Delivery Form (the Form) for each and every vehicular trip
transporting C&DM, i.e. public fill or C&D waste, off Site. The
Contractor shall complete the Form in duplicate.
· Prior to the vehicle leaving the Site, the Contractor shall present to the site supervisory staff the completed Form. The site supervisory staff shall retain a copy of the Form and return the original to the Contractor. The Form shall be carried on board the vehicle at all times throughout the vehicular trip.
· For each vehicular trip, the Contractor shall obtain a receipt from the operator of the public filling facility or the landfill. The Contractor shall submit the original receipt to the Engineer's Representative within 5 working days of the vehicular trip. Late return without any acceptable reason might be regarded as non-compliance by the Engineer's Representative.
· The Contractor acknowledges and shall permit the Engineer Representative to request and obtain information from the operator of the Designated Disposal Tip verifying the receipt and the accuracy of the information on that receipt.
· All C&DM shall become the property of the Contractor when it is removed from the Site. The Contract should make provision that the Contractor will deliver material to the designated locations as agreed with CED.
· The Contractor will be required to complete the relevant details on a standard form and submit the form for stamping and collection by site supervisory staff and submit to Engineer Representative the receipt issued by the operator of the public filling facility/landfill after the disposal of the C&DM. Details to be included on the standard form and the receipt are specified in WBTC No. 5/99 (will be replaced by WBTC No. 21/2002 in September 2002).
5.3.20 For those processes that generate chemical waste, it may be possible to find alternatives which generate reduced quantities or even no chemical waste, or less dangerous types of chemical waste.
5.3.21 Chemical waste, as defined by Schedule 1 of the Waste Disposal (Chemical Waste) (General) Regulation (CWR), should be handled in accordance with the Code of Practice on the Packaging, Handling and Storage of Chemical Waste published by the EPD. The producer of chemical wastes should be registered as chemical waste producer in accordance with the CWR.
5.3.22 Containers used for the storage of chemical waste should:
· be suitable for the substances to be held, resistant to
corrosion, maintained in good condition, and securely closed;
· have a capacity of less than 450 liters unless the specifications have been approved by the EPD; and
· display a label in English and Chinese in accordance with instructions prescribed in Schedule 2 of the CWR.
5.3.23 The storage area for chemical waste should:
· be clearly labeled and used solely for the storage of chemical waste;
· be enclosed on at least three sides;
· have an impermeable floor and bunding, of capacity to accommodate 110% of the volume of the largest container or 20% by volume of the chemical waste stored in that area, whichever is the greatest;
· have adequate ventilation;
· be covered to prevent rainfall entering (water collected within the bund must be tested and disposed as chemical waste if necessary); and
· be arranged so that incompatible materials are adequately separated.
5.3.24 Disposal of chemical waste should be:
· via a licensed waste collector; and
· at a recycling, treatment or disposal facility that is licensed under the Waste Disposal Ordinance to receive chemical waste, such as the Chemical Waste Treatment Centre at Tsing Yi.
5.3.25 With the implementation of the above measures, potential environmental impacts from the storage, handling and disposal of a small amount of chemical waste generated by the construction activities of the Project would be negligible.
5.3.26 General refuse should be stored in enclosed bins or compaction units separate from C&DM and chemical wastes. A reputable waste collector should be employed by the contractor to remove general refuse from the site, separate from C&DM and chemical wastes, and on a regular basis in order to minimize odour, pest and litter impacts. The burning of refuse at site is not permitted under the Air Pollution Control Ordinance (Cap 311).
5.3.27 Reusable rather than disposable dishware should be used if feasible. Aluminium cans can often be recovered from the waste stream by recyclers if these are segregated or if access is provided. Labelled bins for the deposit of aluminium cans should be provided if feasible.
5.3.28 Office waste can be reduced through recycling of paper if volumes are large enough to warrant collection. Participation in a local collection scheme should be considered if one is available.
5.3.29 Good management practices should be implemented to ensure that refuse is properly stored and is transported for disposal of at licensed landfills, i.e. WENT.
5.4 Environmental Audit
5.4.1 Auditing of each waste stream should be carried out periodically to determine if waste is being managed in accordance with prescribed procedures and the WMP. The audits should examine all aspects of waste management including waste generation, storage, recycling, treatment, transportation, disposal and their records.
5.4.2 The general site inspections including waste management issues will be undertaken weekly by Environmental Team to check all construction activities for compliance with all appropriate environmental protection and pollution control measures, including those set up in the WMP. Meanwhile, waste management audit will be carried out on monthly basis by the IEC.