8.1.1
This section identifies the
types of construction- and operation-related wastes that are likely to be
generated by the Project and evaluates the potential environmental impacts that
may result from handling, transport and disposal of the waste.
8.1.2
The main environmental concern
regarding waste arises from the construction and demolition materials from
earthworks and general construction waste/surplus materials for the proposed cavern
development. Mitigation measures and good site practices, including waste
handling, storage and disposal have been recommended with reference to the
applicable waste legislation and guidelines.
8.2.1
The criteria and guidelines for
assessing waste management implications are outlined in Annex 7 and 15,
respectively, of the Technical Memorandum
on Environmental Impact Assessment Process (EIAO-TM).
8.2.2
The following legislation,
which has been used in assessing potential impacts, relates to the handling,
treatment and disposal of wastes in the Hong Kong SAR:
Ÿ
Waste Disposal Ordinance (Cap.354);
Ÿ
Waste Disposal (Chemical Waste)(General) Regulation (CAP.354C);
Ÿ
Waste Disposal (Charges for Disposal of Construction Waste)
Regulation (Cap.354N);
Ÿ
Land (Miscellaneous Provisions) Ordinance (Cap.28);
Ÿ
Public Health and Municipal Services Ordinance (Cap.132BK) –
Public Cleansing and Prevention of Nuisances Regulation.
Waste Management
8.2.3
The Waste Disposal Ordinance (WDO) prohibits the unauthorised disposal
of wastes. Construction waste, defined under Cap. 354N of the
WDO means any substance, matter or thing that is generated from construction
works and abandoned, whether or not it has been processed or stockpiled before
being abandoned, but does not include any sludge, screenings or matter removed
in or generated from any desludging, desilting or dredging works. Under WDO, waste can be disposed of
only at designated waste disposal facilities licensed by the Environmental Protection Department (EPD).
8.2.4
Issued under the WDO, the Chemical Waste (General) Regulation 1992
administers the possession, storage, collection, transport and disposal of
chemical wastes. The EPD has also issued a ‘guideline’ document, the Code of Practice on the Packaging, Labelling
and Storage of Chemical Wastes (1992), which details how the Contractor
should comply with the regulations on chemical wastes.
8.2.5
The Public Cleansing and Prevention of Nuisances Regulation provides control on illegal tipping of wastes on
unauthorised (unlicensed) sites.
Construction of Demolition (C&D) Materials
8.2.6
The current policy related to
the dumping of C&D materials is documented in the Works Branch Technical Circular (WBTC) No.
2/93, ‘Public Dumps’. Construction and demolition materials that are wholly
inert, namely public fill, should not be disposed of to landfill, but taken to
public filling areas. That usually form part of reclamation schemes. The Land (Miscellaneous Provisions)
Ordinance requires that dumping licences be obtained by individuals or
companies who deliver public fill to public filling areas. The licences are
issued by Civil Engineering and Development Depart (CEDD) under delegated
powers from the Director of Lands.
8.2.7
In addition to the WBTC, EPD
and CEDD have produced a leaflet titled ‘New
Disposal Arrangements for Construction Waste’ (1992) and together with the
approved Construction Waste Disposal
Charging Scheme (2005) by the Legislative Council that C&D materials
with less than 50% by weight of inert materials will be accepted at landfill.
If the C&D materials contain more than 50% inert materials, the waste must
be sorted with inert materials sent to a public filling area and the non-inert
materials (that is, C&D waste) sent to landfill for final disposal.
8.2.8
Measures have been introduced
under Paragraph 4.1.3 of Chapter 4 of the
Project Administration Handbook for Civil Engineering Works to enhance the
management of C&D materials including rock, and to minimize its generation
at source. The enhancement measures include:
(i)
Drawing up a Construction and Demolition
Material Management Plan (C&DMMP) at an early design stage to minimize
C&D materials generation;
(ii)
Vetting of the C&DMMP prior to upgrading
of the project to Category A in the Public Works Programme; and
(iii)
Providing the contractor with information
from the C&DMMP in order to help the contractor prepare the Waste
Management Plan (WMP) and to minimize C&D materials generation during
construction.
8.2.9
Technical circular ETWB TCW No. 19/2005 introduces
additional measures to enhance waste management on construction sites. The
circular sets out the policy and procedures requiring contractors to prepare
and implement an enhanced WMP to encourage on-site sorting of C&D materials
and to minimize generation of C&D materials during the course of
construction.
Chemical Waste
8.2.10
Under the regulation of WDO,
the Waste Disposal (Chemical Waste)(General) Regulation provides regulations of
chemical waste control, and administers the possession, storage, collection,
transport and disposal of chemical wastes. EPD has also issued a ‘guideline’
document, the Code of Practice on the Packaging, Labelling and Storage of
Chemical Wastes (1992), which details how the Contractor should comply with the
regulations on chemical wastes.
8.3.1
The methods of assessing
potential waste management impacts during the construction and operational
phases follow the presented in Annex 15 of the EIAO-TM and include the
following:
Ÿ Estimation of the types and
quantities of the wastes generated;
Ÿ Examination of
opportunities for waste reduction and re-use (both on-site and off-site) and
the required disposal options for each type of waste;
Ÿ Assessment of potential
environmental impacts from the transport/management of solid waste with respect
of potential hazards, air and odour emissions, noise, wastewater discharges;
and
Ÿ Identification of impacts
on the capacity of waste collection, transfer and disposal facilities.
8.4.1
The construction activities to
be carried out for the proposed Project would be generate a variety of wastes
that can be divided into distinct categories based on their composition and
ultimate method of disposal. The identified wastes types are:
Ÿ Construction and demolition
(C&D) materials.
Ÿ General refuse.
Ÿ Chemical waste.
8.4.2
General refuse would be the
major waste generated during operation of the Project.
8.5.1
The nature of each type of
waste arising is described below, together with an evaluation of the potential
environmental impacts associated with the waste.
Construction Phase
Construction and Demolition
Materials
8.5.2
Construction and demolition
(C&D) materials would be generated from excavation works for museum cavern
which include: Main Museum, Entrance/Exit Adits and
M&E Niches. The C&D materials would comprise both inert and non-inert
components, such as vegetation, soil, artificial hard materials (AHM) (i.e. broken
concrete, etc), rocks, wood and metals. The Engineer
has estimated the volume of surplus C&D materials to be approximately 18,175m3
of inert materials and approximately 310m3 of non-inert materials.
There is no sediment present requiring marine disposal.
8.5.3
The C&D materials would be
sorted on-site and the inert portion would be stored in different containers,
skips or stockpiles to re-use on-site as far as possible to minimise the net
amount of C&D materials generated from this Project. Surplus excavated materials, mainly the excavated
rock material of size over 200mm, would be recycled and crushed into aggregates
for reuse either at the main site of the ARQ project or other construction
projects. The Project Proponent shall notify Public
Fill Committee (PFC) of CEDD for the estimated spoil volumes to be generated, liaise
and obtain confirmation from the PFC and GEO/Mines of CEDD for the crushing and
recycling arrangement of surplus inert C&D materials during the detailed
design phase of the Project. A summary of inert C&D materials generated
during construction phase is show in Table 8.1. The potential
environmental impacts arising from the handling and disposal of the inert
C&D materials, such as air and odour emissions, noise and potential hazard,
would be negligible. Appropriate measures should be taken to minimise potential
adverse impacts from dust during the transportation of C&D materials.
Table 8.1 Summary of Inert C&D Materials
Quantities Generated
|
Works Area
|
Granitic Rock (Grade III or below)(m3)
|
Soft Material (Fill, etc.)( m3)
|
Artificial Hard materials (m3)
|
Total Volume
(m3)
|
|
Museum
Cavern
|
18,175
|
0
|
N/A
|
18,175
|
8.5.4
The estimated volumes of inert
and non-inert C&D materials generated from the construction of the Project
are presented in Table 8.2 below, together with the estimated volumes of
inert C&D materials to be recycled and crushed into aggregates for reuse
either at the main site of the ARQ project or other construction projects. The timing
of these construction activities is shown in Table 8.3.
Table 8.2 Summary of Inert and non-inert
C&D Materials Volumes Generated from Consturction Activities (in Bulk
Volumes)
|
Consturction
Activity
|
Inert
C&D materials (m3)
|
Reusable
inert C&D materials (m3)
|
Inert
C&D materials to recycled and crushed into aggregates for reuse either
at the main site of the ARQ project or other construction projects (m3)
|
Inert
C&D materials to be Disposed to Public Filling Area (m3)
|
Non-inert
C&D materials (m3)
|
|
Portal
Area (Entrance/Exit Adit and M&E Niches) excavation
|
5,720
|
1,715
|
4,005
|
N/A
|
310
|
|
Main
Museum excavation
|
12,455
|
3,735
|
8,720
|
N/A
|
N/A
|
|
Permanent
cavern (and adits) lining construction
|
N/A
|
N/A
|
N/A
|
N/A
|
N/A
|
|
Total
|
18,175
|
5,450
|
12,725
|
N/A
|
310
|
Table 8.3 Anticipated Timing of Wastes Arising/Generation from Construction
Activities and Disposal
|
Consturction
Activity
|
Anticipated
Timing
|
|
Portal
Area (Entrance/Exit Adit and M&E Niches) excavation and Portal slopes
stabilisation works
|
Jan 2017 to Apr 2017
|
|
Main
Museum Excavation and temporatory support installation
|
Apr 2017 to Feb 2018
|
|
Permanent
cavern (and adits) lining construction
|
Feb 2018 to Jul 2018
|
8.5.5
It is anticipated that any fill
materials required will be sourced from the excavated materials stockpiled at
the temporary stockpiling areas, whenever is suitable. Hence, no imported fill
will be required.
8.5.6
Non-inert C&D materials
generated would be reused and recycled as much as possible before disposing to
landfills. It is the Contractor’s
responsibility to separate the inert and non-inert C&D materials on site.
8.5.7
The Contractor would quantify
in the site Waste Management Plan the amount of C&D materials expected to
be generated.
General Refuse
8.5.8
Throughout construction, the
workforce would generate refuse comprising food scraps, waste paper, empty
containers, etc. Escape of such refuse
from the site should not be allowed to occur.
8.5.9
Effective collection and
removal of site wastes will be required to prevent waste materials being blown
around by wind, flushed or leached into the aquatic environment, and to prevent
odour nuisance. The work sites may also
attract pests and vermin if the waste storage area is not well maintained and
cleaned regularly. Disposal of refuse
must be at approved waste transfer or disposal facilities. With the implementation of good waste
management practices at the site, adverse environmental impacts would not be
expected to arise from the storage, handling and transportation of refuse.
Chemical Waste
8.5.10
The maintenance and servicing
of construction plant and equipment may possibly generate some chemical wastes,
for instance, cleaning fluids, solvents, lubrication oil and fuel. Maintenance of vehicles may also involve the
use of a variety of chemicals, oil and lubricants.
8.5.11
Chemical wastes arising during
the construction phase may pose environmental, health and safety hazards if not
stored and disposed of in an appropriate manner as stipulated in the Waste
Disposal (Chemical Waste) (General) Regulations. The potential hazards include:
Ÿ
Toxic effects on the workforce.
Ÿ
Adverse impacts on water quality and aquatic biota from
spills.
Ÿ
Fire hazards.
8.5.12
Materials classified as
chemical wastes will require special handling and storage arrangements before
removal for appropriate treatment at the Chemical Waste Treatment Centre at
Tsing Yi. Wherever possible
opportunities should be taken to reuse and recycle materials. Mitigation and control requirements for
chemical wastes are detailed in Section 8.6. Provided that the handling, storage and
disposal of chemical wastes are in accordance with these requirements, adverse
environmental impacts are not expected to result.
Uncertainties in Prediction & Evaluation of Environmental Impacts
8.5.13
It is difficult to quantify the
amount of general refuse and chemical waste that will arise from the
construction activities since it would be highly dependent on the Contractor’s
on-site maintenance requirements and the number of plant utilised. However, as
a worst case, it is estimated that a factor of 0.65 kg per worker per day of general
refuse will be generated. The total quantity of waste generated would thus be estimated
7.8 kg per day, assuming the size of the work force would be a maximum of 2 resident
site staff (RSS) and 10 construction workers. Also it is anticipated that the
quantity of chemical waste, such as lubricating oil and solvent produced from
plant maintenance, would be small and in the order of a few cubic metres (i.e.
<2m3) in total over the cavern construction period. The amount of
chemical waste to be generated would be quantified in the site Waste Management
Plan to be prepared by the Contractor.
Operational Phase
8.5.14
It is expected that general
refuse will be generated during the operational phase of the Project. As advised
by Leisure and Cultural Services Department, the area
of the quarry exhibition and supporting facilities (including activity room,
demonstration area, reception counter, entrance and exit buffer, office, store
room and etc) will be 1,000m2 and 800m2
respectively. It is assumed that (1) each customer occupy 2.6 m2,
(2) 1 retail staff serves 13 visitors, (3) waste generation rate = 2.69
kg/person/day. By using the above assumptions, it is expected during the
operation of the Project there will be 385 customers and 30 retail staff per
day. As such, the general refuse generated will be about 1,116 kg/day.
8.5.15
The refuse must be disposed at
approved waste transfer or disposal facilities by refuse collection vehicle. As
such it is considered to have no adverse environmental impacts.
Construction Phase
Good Site Practices
8.6.1
Appropriate waste handling,
transportation and disposal methods for all waste arising generated during the
construction works for the Project should be implemented to ensure that
construction wastes do not enter the nearby streams or drainage channel.
8.6.2
It is anticipated that adverse
impacts would not arise on the construction site, provided that good site
practices are strictly followed.
Recommendations for good site practices during the construction
activities include:
Ÿ
Nomination of approved personnel, such as a site
manager, to be responsible for good site practices, and making arrangements for
collection of all wastes generated at the site and effective disposal to an
appropriate facility.
Ÿ
Training of site personnel in proper waste management
and chemical waste handling procedures.
Ÿ
Provision of sufficient waste reception/ disposal
points, of a suitable vermin-proof design that minimises windblown litter.
Ÿ
Arrangement for regular collection of waste for
transport off-site and final disposal.
Ÿ
Appropriate measures to minimise windblown litter and
dust during transportation of waste by either covering trucks or by
transporting wastes in enclosed containers.
Ÿ
Regular cleaning and maintenance programme for drainage
systems, sumps and oil interceptors.
Ÿ
A recording system for the amount of wastes generated,
recycled and disposed (including the disposal sites) should be proposed.
Ÿ
A Waste Management Plan should be prepared and should be
submitted to the Engineer for approval.
One may make reference to ETWB TCW
No. 19/2005 for details.
8.6.3
In order to monitor the
disposal of C&D materials at landfills and public filling areas, as
appropriate, and to control fly tipping, a trip-ticket system should be
included as one of the contractual requirements to be implemented by an
Environmental Team undertaking the Environmental Monitoring and Audit work. One
may take reference to DEVB TCW No.6/2010 for details.
Waste Reduction Measures
8.6.4
Good management and control of
construction site activities/ processes can minimise the generation of waste.
Waste reduction is best achieved at the planning and design stage, as well as
by ensuring the implementation of good site practices. Recommendations to
achieve waste reduction include:
Ÿ
Segregate and store different types of construction related
waste in different containers, skips or stockpiles to enhance reuse or
recycling of materials and their proper disposal.
Ÿ
Provide separate labelled bins to segregate recyclable
waste such as aluminium cans from other general refuse generated by the work
force, and to encourage collection by individual collectors.
Ÿ
Any unused chemicals or those with remaining functional
capacity shall be recycled.
Ÿ
Maximising the use of reusable steel formwork to reduce
the amount of C&D materials.
Ÿ
Prior to disposal of C&D waste, it is recommended
that wood, steel and other metals shall be separated for re-use and / or
recycling to minimise the quantity of waste to be disposed of to landfill.
Ÿ
Adopt proper storage and site practices to minimise the
potential for damage to, or contamination of, construction materials.
Ÿ
Plan the delivery and stock of construction materials
carefully to minimise the amount of waste generated.
Ÿ
Minimize over ordering of concrete, mortars and cement
grout by doing careful check before ordering.
8.6.5
In addition to the above
measures, other specific mitigation measures are recommended below to minimise
environmental impacts during handling, transportation and disposal of wastes.
Construction and Demolition
Materials
8.6.6
The C&D materials generated
from demolition works of slope and cavern should be sorted on-site into inert
C&D materials (that is, public fill) and C&D waste. To minimise the
impact resulting from collection and transportation of C&D materials as far
as practicable, C&D waste, such as wood, plastic, steel and other metals
should be reused or recycled and, as a last resort, disposed to landfill. A
suitable area should be designated within the site for temporary stockpiling of
C&D materials and to facilitate the sorting process. Within the stockpile
areas, the following measures should be taken to control potential
environmental impacts or nuisance:
Ÿ
Waste such as soil should be
handled and stored well to ensure secure containment;
Ÿ
Covering materials during heavy rainfall;
Ÿ
Stockpiling area should be
provided with covers and water spraying system to prevent materials from
wind-blown or being washed away;
Ÿ
Locating stockpiles to minimise potential visual
impacts; and
Ÿ
Minimising land intake of stockpile areas as far as
possible.
General Refuse
8.6.7
General refuse should be stored
in enclosed bins or compaction units separate from C&D materials. A reputable waste collector should be
employed by the contractor to remove general refuse from the site, separately
from C&D materials. An enclosed and
covered area is preferred to reduce the occurrence of 'wind
blown' light material.
Chemical Wastes
8.6.8
If chemical wastes were to be
produced at the construction site, the Contractor would be required to register
with the EPD as a Chemical Waste Producer, and to follow the guidelines stated
in the Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes. Good quality containers
compatible with the chemical wastes should be used, and incompatible chemicals
should be stored separately. Appropriate labels should be securely attached on
each chemical waste container indicating the corresponding chemical
characteristics of the waste such as explosive, flammable, oxidizing, irritant,
toxic, harmful, corrosive, etc. The Contractor shall use a licensed collector
to transport the chemical wastes. The licensed collector shall deliver the
waste to the Chemical Waste Treatment Centre at Tsing Yi, or other licensed
facility, in accordance with the Waste Disposal (Chemical Waste) (General)
Regulation.
Operational Phase
General Refuse
8.6.9
General
refuse should be collected on daily basis and delivered to the refuse
collection point accordingly. A reputable waste collector should be employed to
remove general refuse regularly to avoid odour nuisance or pest/vermin problem.
Sufficient recycling containers are recommended to be provided at suitable
locations to encourage recycling of such waste as aluminium cans, plastics and
waste paper.
8.6.10
Table 8.4 provides a summary of the various waste types likely to be
generated during the construction works for the Project, together with the
recommended handling and disposal methods.