6.1
This section identifies the types of
wastes that are likely to be generated during the construction and operation
phases of the proposed slip roads and evaluates the potential environmental
impacts that may result from these waste arisings. The main solid waste management implications are related to
construction and demolition (C&D) material from the foundation works for
the slip roads. Mitigation measures and
good site practice, including waste handling, storage and disposal are
recommended with reference to the applicable waste legislation and guidelines.
6.2
The operation phase of the slip roads
would generate wastes associated with roadside littering and road maintenance
activities, and the amount would be expected to be minimal. The potential environmental impacts arising
from the handling and disposal of this small amount of waste are anticipated to
be negligible and therefore have not been evaluated further in this report.
6.3
The criteria and guidelines for
assessing waste management implications are outlined in Annex 7 and Annex 15 of
the Technical Memorandum on Environmental Impact Assessment Ordinance
(EIAO-TM), respectively.
6.4
The following legislation relates to
the handling, treatment and disposal of wastes in the Hong Kong SAR and will be
used in assessing potential impacts:
·
Waste Disposal Ordinance (Cap. 354);
·
Waste Disposal (Chemical Waste) (General)
Regulation (Cap. 354);
·
Land (Miscellaneous Provisions) Ordinance (Cap.
28);
·
Public Health and Municipal Services Ordinance
(Cap. 132) - Public Cleansing and Prevention of Nuisances Regulation.
6.5
The Waste Disposal Ordinance (WDO)
prohibits the unauthorised disposal of wastes.
Construction waste is not directly defined in the WDO but is considered
to fall within the category of “trade waste”.
Trade waste is defined as waste from any trade, manufacturer or
business, or any waste building, or civil engineering materials, but does not include
animal waste. Under the WDO, wastes can
be disposed of at sites licensed by the EPD.
6.6
The Public Cleansing and Prevention of
Nuisance Regulation provides control on illegal tipping of wastes on
unauthorised (unlicensed) sites.
Construction and Demolition (C&D) Materials
6.7
The current policy relating to the
disposal of C&D material()
is documented in the Works Bureau Technical Circular No. 2/93B, ‘Public Filling
Facilities’. Construction and
demolition materials that are wholly inert, namely public fill, should not be
disposed of to landfill, but taken to public filling facilities which usually
form part of reclamation schemes. The
Land (Miscellaneous Provisions) Ordinance requires that dumping licences are
obtained by individual or companies who deliver public fill to public filling
facilities. The licences are issued by
the Civil Engineering Department (CED) under delegated powers from the Director
of Lands.
6.8
The Environment, Transport and Works
Bureau (ETWB) Technical Circular (Works) No. 15/2003 sets out the policy and
procedures requiring contractors to prepare and implement an enhanced Waste
Management Plan to encourage on-site sorting of C&D materials and to
minimize their generation during the course of construction.
Chemical Waste
6.9
Under the regulation of WDO, the
Chemical Waste (General) Regulation provides regulations for chemical waste
control, and administers the possession, storage, collection, transport and
disposal of chemical wastes. The
Environmental Protection Department (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.
6.10
The criteria for assessing waste
management implications are outlined in Annex 7 of the EIAO-TM. The methods for assessing potential waste
management impacts during the construction and operation phases of the Project
follow those presented in Annex 15 of the EIAO-TM and include the following:
·
estimation of the types and quantities of the
wastes generated;
·
assessment of potential impacts from the
management of solid waste with respect to potential hazards, air and odour
emissions, noise and wastewater discharges; and
·
impacts on the capacity of waste collection,
transfer and disposal facilities.
6.11
The construction activities to be
carried out for the proposed Project would generate a variety of wastes that
can be divided into distinct categories based on their composition and ultimate
method of disposal. The identified
waste types include:
·
C&D materials;
·
general refuse; and
·
chemical waste.
6.12
The nature of each type of waste
arising is described in the following section, together with an evaluation of
the potential environmental impacts associated with these waste arisings.
Construction and Demolition Materials
6.13
Construction and demolition (C&D)
material would be generated from foundation works for the construction of the
bored piles for the slip roads during the period June 2005 to May 2006 (Figure
2.8 refers). The total volume of
C&D material was estimated by the Project Engineer to be approximately
4,260 m3. A breakdown of
the estimated quantities of C&D material from the different works areas of
the Project is given in Table 6.1 below.
Table 6.1 Summary of Estimated Quantities of
C&D Material
Location
|
Public Fill (m3)
|
Public Fill (m3) (reusable)
|
Location to where the reusable material will
be transported
|
Slip Road A
|
57
|
350
|
To retaining walls at slip road A
|
Slip Road B
|
1,580
|
323
|
To retaining walls at slip road B
|
Slip Road F
|
301
|
1,304
|
To retaining walls at slip roads A & F
|
Bridge A
|
145
|
200
|
To retaining walls at slip road F
|
Total
(m3)
|
2,083
|
2,177
|
|
6.14
The C&D material would be mostly
sand and rock. It was estimated that
approximately 2,177m3 of the C&D material would be suitable for
reuse on-site as fill material during the construction of the retaining walls,
and approximately 2,083 m3 of C&D material comprising soil and
silt/clay would require disposal off-site to the public filling facility
designated by CED.
General Refuse
6.15
Throughout construction, the workforce
would generate general refuse comprising food scraps, waste paper, empty
containers, etc. Release of general
refuse into the adjacent nullahs should not be permitted as introduction of
these wastes is likely to have detrimental effects on water quality in the
area. Rapid and effective collection of
site wastes would be required to prevent waste materials being blown around by
wind, flushed or leached into the aquatic environment, and 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 at sites other than
approved waste transfer or disposal facilities can also result in similar
impacts.
6.16
With the implementation of the
recommended waste management practices at the site, adverse environmental
impacts would not arise from the storage, handling and transportation of
refuse.
Chemical Waste
6.17
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.
6.18
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:
· toxic effects to workers;
· adverse impacts on water quality from spills; and
· fire hazards.
6.19
It is difficult to quantify the amount
of 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, 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 hundred litres per month. The amount of chemical waste
expected to be generated would be quantified in the site Waste Management Plan
to be prepared by the Contractor.
6.20
Materials classified as chemical
wastes would require special handling and storage arrangements before removal
for appropriate treatment at the Chemical Waste Treatment Facility 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 6.28. Provided that
the handling, storage and disposal of chemical wastes are in accordance with
these requirements, adverse environmental impacts are not expected to result.
Good Site Practices
6.21
It is not anticipated that adverse
waste management related impacts would arise, provided that good site practices
are strictly followed. Recommendations
for good site practices during the construction activities include:
·
nomination
of an approved personnel, such as a site manager, to be responsible for the
implementation of good site practices, arrangements for collection and
effective disposal to an appropriate facility, of all wastes generated at the
site;
·
training
of site personnel in site cleanliness, appropriate waste management procedures,
including chemical waste handling procedures, and concepts of waste reduction,
reuse and recycling;
·
provision
of sufficient waste disposal points and regular collection for disposal;
·
appropriate
measures to minimise windblown litter and dust during transportation of waste
by either covering trucks or by transporting wastes in enclosed containers;
·
separation
of chemical wastes for special handling and appropriate treatment at the
Chemical Waste Treatment Facility;
·
regular
cleaning and maintenance programme for drainage systems, sumps and oil
interceptors;
·
a
recording system for the amount of wastes generated, recycled and disposed
(including the disposal sites) should be proposed; and
·
a
waste management plan (WMP) should be prepared in accordance with ETWB TC No.
15/2003 and submitted to the Engineer for approval.
6.22
In order to monitor the disposal of
C&D material at public filling facilities and to control fly tipping, the
Trip-Ticket System in accordance with ETWB TC No. 21/2002 should be included as
one of the contractual requirements and implemented by the Environmental Team
undertaking the environmental monitoring and audit work. Disposal of C&D material shall only be
permitted at the public filling facility designated by CED. C&D material shall not be permitted to
be dumped to fish ponds or other illegal locations.
Waste Reduction Measures
6.23
Good management and control can
prevent the generation of significant amounts 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:
·
segregation
and storage of different types of waste in different containers, skips or
stockpiles to enhance reuse or recycling of materials and their proper
disposal;
·
to
encourage collection of aluminium cans by individual collectors, separate
labelled bins shall be provided to segregate this waste from other general
refuse generated by the work force;
·
any
unused chemicals or those with remaining functional capacity shall be recycled;
·
maximising
the use of reusable steel formwork to reduce the amount of C&D material;
·
proper
storage and site practices to minimise the potential for damage or
contamination of construction materials; and
·
plan
and stock construction materials carefully to minimise amount of waste
generated and avoid unnecessary generation of waste.
6.24
In addition to the above good site
practices and waste reduction measures, specific mitigation measures are recommended
below for the identified waste arisings to minimise environmental impacts
during handling, transportation and disposal of these wastes.
General Refuse
6.25
General refuse should be stored in
enclosed bins or compaction units separate from C&D material. A reputable waste collector should be
employed by the contractor to remove general refuse from the site, separately
from C&D material. An enclosed and
covered area is preferred to reduce the occurrence of 'wind blown' light
material.
Construction and Demolition Material
6.26
In order to minimise the impact
resulting from collection and transportation of C&D material for off-site
disposal, the material suitable for reuse shall be reused on-site as backfill
material as far as possible.
6.27
When disposing C&D material at a
public filling facility, it shall be noted that the material shall only consist
of soil, rock, concrete, brick, cement plaster/mortar, inert building debris,
aggregates and asphalt. The material
shall be free from marine mud, household refuse, plastic, metals, industrial
and chemical waste, animal and vegetable matter, and other material considered
to be unsuitable by the public fill operators.
Chemical Wastes
6.28
If chemical wastes are 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 chemical waste, such as
explosives, flammable, oxidizing, irritant, toxic, harmful, corrosive,
etc. The Contractor shall use a
licensed collector to transport and dispose of the chemical wastes generated at
the Chemical Waste Treatment Centre at Tsing Yi, or other licenced facility, in
accordance with the Waste Disposal (Chemical Waste) (General) Regulation.
6.29
With
the implementation of the recommended mitigation measures for the handling,
transportation and disposal of the identified waste arisings, no residual
impact was anticipated during the construction works for the proposed slip
roads.
6.30
Waste management would be the
contractor’s responsibility to ensure that all wastes produced during the
construction of the Project are handled, stored and disposed of in accordance
with good waste management practices and EPD’s regulations and requirements.