9.1.1.1 This section identifies potential waste management implications that may arise from the construction and operation of the project and assesses potential environmental impacts associated with their handling and disposal. Options of reuse, minimization, recycling, treatment, storage, collection, transport and disposal of such wastes have been examined. Where appropriate, procedures for waste reduction and management have been considered, with environmental control measures to avoid or minimise impacts recommended.
9.1.1.2 A description of the construction works sections and proposed construction works for the Project has been provided in Section 2.7 of this EIA Report, including a summary of construction works in Table 2.7. The overall project is shown in Figure 1.1 with a more detailed layout of the proposed drainage alignment presented in Figures 2.9a-2.9g.
9.2 Environmental Legislation, Standards and Guidelines
9.2.1
General Waste Management
9.2.1.1 The following legislation is relevant to the handling, treatment and disposal of waste in Hong Kong SAR, and will be considered in assessing potential impacts and their avoidance or mitigation:
· Environmental Impact Assessment Ordinance (Cap 499);
· Waste Disposal (Amendment) Ordinance (Cap 354);
· Land (Miscellaneous Provisions) Ordinance (Cap 28); and
· Public Health and Municipal Service Ordinance (Cap 132) - Public Cleansing and Prevention of Nuisances By-laws.
9.2.1.2 Under the Waste Disposal (Amendment) Ordinance, some of the regulations are relevant to this EIA, including:
· Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Cap 354); and
· Waste Disposal (Chemical Waste) (General) Regulation (Cap 354).
9.2.2.1 The Waste Disposal (Amendment) Ordinance (WDO) prohibits unauthorised disposal of wastes. Schedule 5 of the Waste Disposal (Charges for Disposal of Construction Waste) Regulation (Charging Regulation) also defines that the inert construction waste includes rock, rubble, boulder, earth, soil, sand, concrete, brick, tile, masonry or used bentonite.
9.2.2.2 Under the WDO and the charging regulation, wastes can only be disposed of at designated waste disposal facilities licensed by the EPD. For construction work with a value of more than HK$1 million, the main contractor is required to establish a billing account at the EPD before transporting the construction waste to the designated waste disposal facilities (for example, landfill and public fill). The vessels for delivering construction waste to the public fill reception facilities require prior approval from the Public Fill Committee (PFC). Any breach of these regulations may lead to a fine and/or imprisonment.
9.2.3
Waste Disposal (Chemical Waste) (General) Regulation
9.2.3.1 Chemical waste includes any scrap materials or unwanted substances specified under Schedule 1 of this Regulation if such a substance or chemical occurs in such a form, quantity or concentration that causes pollution or constitutes a danger to health or risk of pollution to the environment.
9.2.3.2 A person shall not produce, or cause to be produced, any chemical wastes unless he/she is registered with the EPD, otherwise, it will be an offence and is liable to a fine and/or imprisonment. Chemical wastes must be treated using on-site plant as licensed by the EPD or with engaging a licensed collector to transport the wastes to a licensed facility. For each consignment of wastes, the waste producer, collector and disposer of the wastes must sign all relevant parts of a computerised trip ticket so as to trace wastes from production to disposal.
9.2.3.3 This regulation also prescribes the storage facilities to be provided on-site including the labelling and warning signs. In order to minimise the risks of pollution and danger to human health and life, waste producers are required to prepare and make available written emergency procedures for any spillage, leakage or accidents arising from storage of chemical wastes, and waste producers must also provide employees with training for such procedures.
9.2.4
Public Cleansing and Prevention of Nuisances Regulation
9.2.4.1 This regulation provides further control on the illegal dumping of litter or waste in streets and public places (including water courses, streams, channels etc). Any offence of this regulation would result in a fine and/or to imprisonment.
9.2.5
Other Relevant Guidelines
9.2.5.1 The following guidelines also relate to waste management and disposal:
· Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annex 15 - Guidelines for Assessment of Waste Management Implications, and Annex 7 - Criteria for Evaluating Waste Management Implications;
· Waste Reduction Framework Plan, 1998-2007, Planning Environment and Lands Branch, Government Secretariat (1998);
·
Waste Disposal Plan for
·
· Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes, EPD (1992);
· New Disposal Arrangement for Construction Waste (1992), Environmental Protection Department & Civil Engineering Department;
· Works Branch Technical Circular (WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site;
· WBTC No. 2/93, Public Dumps;
· WBTC No. 2/93B, Public Filling Facilities;
· WBTC Nos.25/99, 25/99A and 25/99C, Incorporation of Information on Construction and Demolition Material Management in Public Works Sub-committee Papers;
·
WBTC No. 12/2000, Fill
Management,
·
WBTC Nos. 6/2002 and 6/2002A, Enhanced Specification for Site Cleanliness and
Tidiness. Works Bureau,
·
WBTC No. 12/2002, Specification
Facilitating the Use of Recycled Aggregates. Works Bureau,
· ETWB TC(W) No. 33/2002 Management of Construction and Demolition Material Including Rock;
·
DevB TC(W)
No. 6/2010, Trip Ticket System for Disposal of Construction & Demolition
Materials, Development Bureau,
· ETWB TC(W) No. 19/2005 Environmental Management on Construction Sites.
9.2.5.2
The ETWB TC(W)
No. 19/2005 also sets out the policy and procedures requiring contractors to
prepare and implement an environmental management plan to encourage on-site
sorting of C&D materials and to reduce C&D waste generation during
construction.
9.3.1.1
The assessment of the
environmental impacts from the handling, storage, collection, transportation
and disposal of waste material generated by the project has been undertaken in
accordance with Annex 7 and Annex 15 of the Technical Memorandum on Environmental Impact
Assessment Process (EIAO-TM).
9.3.1.2 The waste management hierarchy has been applied in the assessment and development of mitigation measures for waste. The waste management hierarchy is a concept which shows the desirability of various waste management methods and comprises the following in order of preference:
· Avoidance;
· Minimisation;
· Recycling/reuse;
· Treatment; and
· Disposal.
9.3.1.3 All opportunities for reducing waste generation have been assessed based upon the following factors:
· Avoiding or minimising waste generation through changes in the design;
· Adopting better management practices to promote segregation of waste materials;
· Reuse and recycling; and
· Diverting waste to public fill banks or other construction sites.
9.3.1.4 The types and quantities of waste have been estimated and disposal options for each category of waste identified, taking into account the existing or future spare capacities of the waste disposal facilities and the environmental implications of the handling, collection and disposal of waste material. The potential environmental impacts associated with the handling, transportation and disposal of waste arising from the construction works will be assessed with reference to the following approach:
· Estimation of the types, timing and quantities of the wastes to be generated and fill to be imported; and
· Assessment of the potential environmental impacts on the capacity of waste collection, transfer and disposal facilities.
9.3.1.5 The impact caused by handling (including stockpiling, labelling, packaging and storage), collection, transportation and re-use/disposal of wastes has been addressed in detail and appropriate mitigation measures have been proposed. This assessment covers the following areas: potential hazard, air and odour emissions, noise, wastewater discharge and public transport.
9.4 Construction Phase Waste Management Assessment
9.4.1
Waste Types
9.4.1.1 The construction of the Ngong Ping Drainage Improvement Works project will involve a number of activities generating waste which can broadly be classified into distinct categories based on their nature and the options for their disposal. These include:
· Excavated construction and demolition (C&D) materials suitable for public fill (no excavation of sediment would occur in this project);
· C&D waste, including cleared vegetation, which is not suitable for public fill;
· Chemical waste;
· General refuse; and
· Sewage.
9.4.2
Details of Work Activities
9.4.2.1 As described in Section 2 of this EIA Report, this project comprises mainly the construction of underground drainage pipes and box culvert. Upon site clearance, site formation works will be carried out which involves the excavation of soil and rocks for the subsequent construction of pipelines and the box culverts by open cut and cover method and, also, installation of underground drain pipes by trenchless pipe jacking method.
9.4.3
Construction and Demolition Materials
9.4.3.1 The C&D materials as a whole generated during construction comprise materials that are suitable for reuse on site or as public fill and a portion of waste that will require disposal to a licensed landfill facility. For the purposes of this assessment, these two fractions are denoted C&D material and C&D waste, respectively and are discussed below.
C&D Materials
9.4.3.2 In accordance with the waste hierarchy presented in Section 9.3.1 above, it is necessary to consider all ways to avoid the generation of material and also reuse within the project. The following methods have been adopted:
· Minimising Generation of C&D Materials: Section 2 of this EIA Report presents that the design of this project has taken into account the environmental benefits arising from an optimised design of the drainage channels so as to reduce the C&D materials and waste being generated. In particular, the adoption of a trenchless construction method would substantially reduce the excavation volume as excavation of the overlaying topsoil is not required using this technique. This is also the case for C&D waste as the trenchless method used in Works Sections 2 and 6 will limit the amount of vegetation to be cleared.
· Maximising Use of C&D Materials: Inert C&D materials from the site clearance and formation works will be reused both on-site and off-site as far as practicable, for example scrapped steel bars to be recycled; earth materials, concrete debris and aggregates for backfilling, etc.
9.4.3.3 The volume of construction and demolition material generated by the project will be dependent on specific operating procedures and site practices and, hence, cannot be quantified as a whole at this stage. However, all falsework will be steel instead of wood. As steel falsework is a proprietary system, it will be reused throughout the project and subsequent projects. Specification of the use of steel will substantially reduce the amount of waste wood that the project will generate.
9.4.3.4 No buildings will be demolished as a result of the project. However, C&D material will be generated as a result of the removal of soil, road surfacing and other hardstanding for the construction of the drains and which is inert and suitable for public fill. A summary of the C&D materials anticipated to arise from the project is provided in Table 9.1.
Table 9.1 Summary
of C&D Materials Arising from the Project
|
Material Type |
Quantity (m3) |
Remarks |
|
Excavated soil |
12,200 |
From the excavation of underground trenches and
receiving pits by open cut-and-cover and installation of underground pipes by
pipe-jacking. |
|
Concrete debris and aggregate |
300 |
From the in-situ casting of underground box culverts by concreting works. |
|
Excavated rock |
2,300 |
Mainly from the excavation of underground trenches and
receiving pits by open cut-and-cover. |
|
Total |
14,800 |
|
9.4.3.5 Some of the C&D material generated by the project has been explored for reuse either on-site or off-site. It is estimated that approximately 7,700m3 of excavated soil would be reused on-site for backfilling of trenches and pits. The possibility of maximizing the reuse of more excavated soil would be explored during the construction stage taking account of the soil condition. This on-site reuse of C&D materials would lessen the impacts due to transportation.
9.4.3.6 The balance of approximately 7,100m3 of C&D materials (4,500m3 of excavated soil; 300m3 of concrete debris and aggregate; 2,300m3 of excavated rocks) is proposed to be delivered from the project site to the Tseung Kwan O Area 137 Fill Bank via the Public Fill Reception Facility in Mui Wo. The transportation of the material would be undertaken over the 30-month construction period between May 2014 to October 2016 (Figure 2.8b Recommended Construction Programme (Tentative) in Section 2 of this EIA Report).
9.4.3.7 Given the average truck capacity of 7.5m3, a total of approximately 948 trucks would be required over these 30 months of construction works. Based upon the materials being exported on a regular basis for the majority of the construction period, this would equate to around only a maximum of 10 trips per day, assuming a 6-day working week. Therefore, it is not predicted that this minimal increase of traffic would cause any additional impacts to sensitive receivers along the delivery route between Ngong Ping to Mui Wo.
9.4.3.8
While, no significant impacts
associated with the C&D materials are predicted, waste management measures
to control stockpiling, temporary storage and on-site transportation
requirements, which could lead to short-term dust, visual and noise impacts,
particularly to the residents and visitors to Ngong Ping will be required. The construction works and the waste
handling activities have been included in the construction air, noise and
landscape and visual impact assessments and are considered to be minor and
acceptable. In
addition, improper waste handling and storage could result in adverse impacts
on the water courses in the area which are ecologically sensitive. The C&D materials will be
carefully stockpiled if it cannot be reused or removed to avoid dust and other
nuisance impacts. In particular, to avoid potential contamination to the
9.4.3.9 No construction works will be 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 department and parties.
9.4.3.10 Mitigation measures to control any impacts from C&D material are detailed in Section 9.5 below.
C&D Waste
9.4.3.11 In addition to the C&D materials that will be generated by the project and will be suitable for reuse as public fill, some C&D waste will be generated during the construction phase. These materials will include:
· Cleared vegetation;
·
Wood from formwork;
·
Plastics;
·
Glass;
· Unusable cement mixes;
· Bentonite slurry (approximately 15m3 arising from the pipe-jacking works and as assessed in Section 5 on Water Quality of this EIA Report); and
· Damaged or contaminated construction materials.
9.4.3.12 The volume of non-inert C&D wastes including cleared vegetation and top soil, and used wood formwork generated by the project will depend on specific operating procedures and site practices and, is expected to be approximately 100 tonnes.
9.4.3.13 The formwork needed for the cut and cover works for the box culvert would likely consist of 18mm plywood. This material would be used only once for this purpose but can be reused throughout the construction process for other activities. The amount of wood required for formwork would be minimal and assuming the material was recycled and reused prior to disposal, the impacts of this would not be significant.
9.4.3.14 The other types of C&D waste are, also, expected to be limited, with only small quantities of maintenance and packaging waste being generated. Given that the material will be generated will be of in small quantities, significant impacts associated with its handling and disposal would not be expected.
9.4.3.15 In accordance with the waste hierarchy presented in Section 9.3.1 above, the adoption of the trenchless construction method for pipelines in Works Sections 2 and 6 will limit the amount of vegetation to be cleared. Further measures to minimise the generation of waste shall be implemented and demolition waste shall be sorted to avoid contamination of the materials suitable for public fill but significant impacts would not be anticipated from the handling, storage or disposal of this material.
Chemical Waste
9.4.3.16 Chemical wastes likely to arise from the construction activities for this project would include:
· Scrap batteries or acid/alkali from maintenance activities;
· Used paints, engine oils, hydraulic fluids and waste fuel;
· Spent mineral oils/cleansing fluids from machinery; and
· Spent solvents/solutions, some of which may be halogenated, from equipment cleansing activities.
9.4.3.17 Chemical wastes may pose environmental, health and safety hazards if not stored and disposed of appropriately as outlined in the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packing, Labelling and Storage of Chemical Waste. These hazards may include:
· Toxic effects to workers;
· Adverse effects on air quality, water quality and ecological sensitive receivers;
· Contamination of land and water due to spillage;
· Hazards of fire; and
· Disruption of sewage treatment works should the chemical waste enter the sewerage system.
9.4.3.18 It is difficult to quantify the amount of chemical waste, but it is estimated to be less than 100L per month, depending on the Contractor’s on-site maintenance practices and the number of mechanical plant and vehicles utilised on-site. However, given the relatively small scale of this project, if the chemical waste is handled, stored, transported and disposed of in an appropriate manner, impacts would not be anticipated.
9.4.3.19
Notwithstanding, the Contractor
should register to the EPD as a Chemical Waste Producer pursuant to the
Regulation and the chemical waste should be collected by licensed collectors
for subsequent disposal at licensed waste disposal facilities, for example the
Chemical Waste Treatment Centre in Tsing Yi.
In addition, all chemical waste shall be stored at the Site Office (SO),
which is outside the
9.4.3.20 The presence of the construction site with workers and the site office would generate a variety of general refuse which will need disposal, consisting mainly of food waste, aluminium cans, waste paper, etc.
9.4.3.21 The storage of general refuse has the potential to cause adverse environmental impacts, e.g. odour nuisance if the waste is not collected frequently, windblown litter, water quality impacts if the waste enters water bodies, visual impacts, etc. Construction sites may also attract pests, vermin and other disease vectors if the waste storage areas were not well maintained. Disposal of waste at areas other than approved refuse transfer stations and landfills can also lead to similar adverse impacts.
9.4.3.22 The number of workforce (clerical and workers) to be employed for this project is expected to be approximately 30 people per day over the 30-month construction period. Based on a generation rate of 0.65 kg per worker per day, the maximum daily arising of general refuse during the construction period would be approximately 20kg only (or approximately 16 tonnes for the entire construction period).
9.4.3.23 Provided that mitigation measures are adopted, potential environmental impacts caused by the storage, handling, transport and disposal of general refuse would be expected to be insignificant. It is recommended that the general refuse should be collected on a regularly basis and transferred to the Outlying Islands Transfer Facilities (OITF) in Mui Wo and then to WENT Landfill. Given the relatively small quantities of general refuse expected, adverse impacts to the operation of the OITF and WENT Landfill would not be expected.
Sewage
9.4.3.24 The construction workforce will produce sewage which requires proper disposal. The sewerage from the site office will be connected to the existing sewer networks and treated at the Ngong Ping STW. However, alignment where there are no foul sewers and chemical temporary toilets will be required at the various works areas. In order to avoid unacceptable odour problems and to safeguard the health of the workers, nightsoil will need to be removed and disposed of off-site frequently. The details of the chemical toilets shall be submitted to WSD prior to the construction commencement
9.5 Operational Phase Waste Management Assessment
9.5.1.1 Since the proposed drainage system will not be in operation for most of the time and any stormwater that will flow into the drain will flow by gravity, maintenance works are anticipated to be minimal. As indicated in the layout drawings, Figure 2.7a-2.7e, there will be sand-traps at the intakes which will limit debris entering the drain pipes and box culvert.
9.5.1.2 Both inert materials (e.g. soil, sand, boulder, etc) and non-inert materials (e.g. refuse, tree debris, etc) would be generated from the maintenance of the proposed drainage system, and no sediment would be anticipated. As the quantity of the inert and non-inert materials anticipated to be removed from the maintenance of the drainage system will be limited, adverse impacts would not be expected during the operational phase of the project. However, some mitigation measures to reduce the level of impacts are proposed in Section 9.6.2 below. Based upon the implementation of the recommended measures, adverse waste implications during the operational phase of this project would not be anticipated.
9.6.1.1
Mitigation measures are
required to ensure the proper handling, storage, transportation and disposal of
waste being carried out during construction phase of this project. Also, measures to ensure that the generation
of waste is avoided and minimised and that waste materials are recycled and
treated as far as practicable. The
recommended mitigation measures for all categories of waste are detailed below
and summarised in Section 11 of the EIA Report. The recommended measures are
considered to be tried and tested techniques implemented on many
(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
future Contractor should be requested to
submit a Waste Management Plan (WMP), which becomes part of the Environmental
Management Plan (EMP), 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 DevB TC(W) No. 6/2010 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 volumes of excavated materials
to be generated and the Public Fill Committee should be notified and agreement
sort on the disposal of surplus inert C&D materials. 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
site and surroundings shall be kept tidy and litter free.
(viii)
No
waste shall be burnt on-site.
(ix)
Make
provisions in contract documents to allow and promote the use of recycled
aggregates where appropriate.
(x)
The
Contractor will be prohibited to dispose of C&D materials within the
proposed site and at any sensitive locations including Lantau North Country
Park, the Lantau South Country Park, the Ngong Ping Site of Special Scientific
Interest, the Lantau Peak Special Area and Site of Special Scientific Interest
and the Conservation Area, etc. The
Contractor should propose the final disposal sites in the EMP and WMP for
approval before implementation.
(xi)
Stockpiled
material shall be covered by tarpaulin and /or watered as appropriate to
prevent windblown dust and surface run off.
(xii) Major stockpiled areas shall be sited outside of the country parks area (Works Section 6) and away from stream courses as far as practicable. For the stockpiling area SA4 within the country park area, stockpiling of earthed material shall be minimised and excavated soil from Works Section 6 shall be delivered to the Site Office as soon as possible. Similarly, overnight stockpiling of earthed material along the exposed trench shall be minimised as far as possible and the excavated soil shall be transferred to the designated stockpiling area as soon as possible.
(xiii)
Excavated
material in trucks shall be covered by tarpaulins to reduce the potential for
spillage and dust generation.
(xiv)
Wheel
washing facilities shall be used by all trucks leaving the site to prevent
transfer of mud onto public roads.
(xv)
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.
(xvi)
The
Contractor should recycle as many C&D materials 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.
(xvii)
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;
·
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.
(xviii)
All chemical waste, fuels and oils shall be stored
at the Site Office area, to minimise impacts to the
(xix) All maintenance activities which may generate chemical waste shall be undertaken in Site Office area, as far as possible.
(xx) The Contractor shall comply with WSD’s General Conditions for Working within Water Gathering Grounds if applicable.
(xxi)
Waste
oils, chemicals or solvents shall not be disposed of to drain.
(xxii)
Subject
to agreement with Water Service Department, 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.
(xxiii)
General
refuse arising on-site should be stored in enclosed bins or compaction units
separately from C&D and chemical wastes. General refuse shall be removed from Works
Section 6 within the country park on the regular basis. 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 regularly and shall be disposed of to
the nearest licensed landfill or refuse transfer station. Burning of refuse on construction sites is
prohibited.
(xxiv)
All
waste containers shall be in a secure area on hardstanding.
(xxv)
Aluminium
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.
(xxvi)
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, aluminium cans, plastic bottles, etc should be provided on-site.
(xxvii)
Training
shall be provided to workers about the concepts of site cleanliness and
appropriate waste management procedure, including waste reduction, reuse and
recycling.
9.6.2.1 As the quantity of inert material and possibly vegetation removed from the maintenance of the drainage system will be limited, adverse impacts would not be expected during the operational phase of the project. However, some mitigation measures to reduce the level of impacts are recommended as follows:
(i) Non-inert materials such as garbage and possibly vegetation will be disposed to WENT Landfill via the OITF in Mui Wo;
(ii)
Inert material, such as excess soil,
sand and boulders, should be delivered from the project site to the Tseung Kwan
O Area 137 Fill Bank via the Public Fill Reception Facility in Mui Wo or to WENT
Landfill if the amount is negligible; and
(iii)
No marine disposal of
dredged/excavated sediment would be involved in this project.
9.7 Waste Disposal Recommendations
9.7.1.1 Based upon the estimated quantities and types of waste expected to be generated by this project during the construction phase, the disposal options have been proposed, as detailed in Table 9.2. In terms of the disposal of general refuse, disposal at the WENT Landfill via the facilities in Mui Wo is recommended. The OITF in Mui Wo has a design capacity of 145 tonnes per day, whilst the total general refuse quantity to be generated by the project is expected to be about 16 tonnes over the total contract period only. Given that other large scale construction projects, which would use the Mui Wo OITF for handling of their general refuse, are not envisaged to be implemented on Lantau in the same time period, it is considered that the OITF would have sufficient capacity for this project. In terms of C&D materials, about 18 tonnes per day on average is expected and disposal should be to the closest Public Fill Reception Area which is at Mui Wo and has a capacity of up to 700-800 tonnes per day. Similarly, as the implementation of other large scale construction projects is not anticipated, the Public Fill Reception Facility in Mui Wo would be considered to have more than sufficient capacity to accept the project waste. Chemical wastes will be disposed of at the Chemical Waste Treatment Centre in Tsing Yi or other licensed facilities via licensed collectors.
Table 9.2 Recommended
Waste Disposal Sites
|
Type of Waste |
Disposal Site |
Quantity to
be Disposed |
|
C&D materials |
TKO Area 137 Fill
Bank via Public Fill
Reception Facility in Mui Wo |
Excavated soil: ~4,500 m3 Concrete debris and aggregate: 300 m3 Excavated rocks: ~2,300 m3 |
|
C&D waste
(plastics, glass, wood, including cleared vegetation etc.) |
WENT Landfill |
~100 tonnes |
|
Chemical waste (as
defined under Schedule 1 of the Waste Disposal (Chemical Waste) Regulation) |
Chemical Waste
Treatment Centre in Tsing Yi or other licensed facilities via licensed
collectors |
< 3,000 L |
|
General refuse |
WENT Landfill via Outlying |
~16 tonnes |
Note:
The small amount of ~15m3 of
dewatered
bentonite slurry would be disposed to a public filling area, and liquid
bentonite slurry if mixed with inert fill material would be disposed to a
public filling area.
9.7.1.2
During the operation phase, the quantity of waste of debris and possibly vegetation removed during the maintenance of the intakes will
be limited and the estimated amount of debris material is not likely to exceed
5m3 per annum. Non-inert
materials such as fallen vegetation and garbage will be disposed to WENT Landfill
via the OITF in Mui Wo,
and inert material such as excess soil, sand
and rocks will delivered from the project site to the Tseung Kwan O Area 137
Fill Bank via the Public Fill Reception Facility in Mui Wo or to WENT Landfill if
the amount is negligible.
9.8
Potential for
9.8.1.1 As discussed in Sections 1 and 2 of this EIA Report, this project site is located near the existing well known, historical village residential houses of Ngong Ping Tsuen, Po Lin Monastery, columbarium and other temples in the close vicinity, in which the proposed drainage system will be aligned underneath existing footpath, access routes and vegetation areas. The surrounding environment and land uses are mainly shrubby grasslands, natural watercourses, gabion channel and rural area. The residential areas are rural in nature and mainly comprise agricultural and residential village houses. Also, portions of the works site fall in areas zoned “Green Belt” and in close proximity to an area zoned “Conservation Area”. Details of historic land use and records from a reconnaissance site visit and verbal inquiries with local villagers are included in Appendix H1, which shows the preliminary appraisal of the Works Sections and Works Areas in this Project. Based upon the above, no hotspots of land contamination were identified within or in the vicinity of the Project site and impact due to land contamination issues would be unlikely.
9.9.1.1 As discussed in Section 2, there are no known concurrent projects in
the Study Area that may result in cumulative impacts with the Project.
9.10.1.1 The residual impacts refer to the net impacts after mitigation, taking into account the background environmental conditions and the impacts from existing, committed and planned projects. Residual impacts associated with the construction have been assessed but no quantification of residual impacts is required.
9.10.1.2 Assuming all the mitigation measures are implemented and the overall short term and temporary nature of the construction works, adverse residual impacts associated with the handling, storage, transportation or disposal of the waste generated by the project would not be anticipated and would not be expected to affect the health and welfare of the local community.
9.11 Environmental Monitoring and Audit
9.11.1.1 The assessment has concluded that the handling, transportation and disposal of waste materials during construction and operational phases if the project will not give rise to significant impacts if appropriate mitigation measures are implemented. However, it is recommended that during construction phase, regular site inspections and supervision of the waste management procedures shall be undertaken as part of the EM&A procedures, to ensure proper control, that all waste is removed from the site area as appropriate and illegal disposal of waste is not being undertaken. Waste EM&A during the operation phase is not required. Further details of the specific construction phase EM&A requirements are detailed in Section 10 of this report and in the EM&A Manual under separate cover.
9.12.1.1 The quantity and timing for the generation of waste during the construction phase have been estimated. Measures, including the opportunity for on-site sorting, reusing excavated fill materials (on-site and off-site) etc., have been devised in the construction methodology to minimise the surplus materials to be disposed off-site. The annual disposal quantities for C&D materials and their disposal methods have also been assessed and recommendations have been made for the Contractor for implementation of measures during the construction period to minimise the waste generation and any off-site disposal. The types and quantities of waste that would be generated during the operation phase have been assessed and recommendations have been made to ensure proper treatment and disposal of these wastes. No construction work will be 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 department and party.
9.12.1.2 In addition, no hotspots of land contamination were identified within or in the vicinity of the Project site and impact due to land contamination issues would be unlikely. The waste impacts are not predicted to significantly affect the health or welfare of the community. Adverse residual impacts would not be anticipated during either the construction and operation phases of this Project.