This section identifies the potential
wastes arising from the construction, operation, restoration and aftercare of
the Extension and potential environmental impacts associated with the handling
and disposal of waste. The assessment was undertaken in accordance with the
criteria presented in Annexes 7 and 15 of the EIAO-TM, which are summarised as follows:
·
Evaluate
opportunities to reduce, reuse and recycle waste;
·
Estimate
the types and quantities of the wastes to be generated; and
·
Assess
the secondary environmental impacts due to the management of waste with respect
to potential hazards, air and odour emissions, noise, wastewater discharges and
traffic.
The following legislation covers, or has
some bearing upon, the handling, treatment and disposal of wastes in
·
Waste Disposal Ordinance (Cap 354);
·
Waste Disposal (Chemical Waste) (General)
Regulation (Cap 354C);
·
Land (Miscellaneous Provisions) Ordinance
(Cap 28); and
·
Public Health and Municipal Services
Ordinance (Cap 132) - Public Cleansing and Prevention of Nuisances Regulation.
The Waste Disposal Ordinance (WDO) prohibits
the unauthorised disposal of wastes, with waste defined as any substance or
article, which is abandoned. Under
the WDO, wastes can only be disposed
of at a licensed site. A breach of
these regulations can lead to the imposition of a fine and/or a prison sentence. The WDO
also provides for the issuing of licences for the collection and transport
of wastes. Licences are not,
however, currently issued for the collection and transport of construction
waste or trade waste.
The Waste Disposal (Charges for Disposal of
Construction Waste) Regulation defined construction waste as any substance,
matters or things that is generated from construction work and abandoned,
whether or not it has been processed or stockpiled before being abandoned, but
does not include any sludge, screening or matter removed in or generated from
any desludging, desilting
or dredging works.
The
Construction Waste Disposal Charging Scheme came into operation on 1 December
2005. Processing of account
applications by the EPD started on the same day. A contractor who undertakes construction
work with value of HK$1 million or above is required to open a billing account
solely for the contract. Charging
for the disposal of construction waste started on 20 January 2006.
Depending on the percentage of inert materials in the material, construction
waste can be disposed of at public fill reception facilities, landfills and
outlying islands transfer facilities, where differing disposal costs would be
applied. The scheme encourages
waste reduction so that the contractor or Project Proponent can minimise their
costs. Table 7.2a summarises the Government’s construction waste disposal
facilities, the types of waste accepted and disposal the associated costs.
Table 7.2a Government
Waste Disposal Facilities for Construction Waste
|
Government Waste Disposal Facilities |
Type of Construction Waste Accepted |
Charge Per Tonne |
|
Public
fill reception facilities |
Consisting
entirely of inert construction waste |
$27 |
|
Sorting
facilities |
Containing
more than 50% by weight of inert construction waste |
$100 |
|
Landfills
|
Containing
not more than 50% by weight of inert construction waste |
$125 |
|
Outlying |
Containing
any percentage of inert construction waste |
$125 |
Chemical waste as defined under the Waste Disposal (Chemical Waste) (General)
Regulation includes any substance being scrap material, or unwanted
substances specified under Schedule 1
of the Regulation, if such a
substance or chemical occurs in such a form, quantity or concentration so as to
cause pollution or constitute a danger to health or risk of pollution to the
environment.
Chemical waste
producers shall register with the EPD.
Any person who contravenes this requirement commits an offence and is
liable to a fine and imprisonment.
Producers of chemical wastes must treat their wastes, utilising on-site
plant licensed by the EPD or have a licensed collector take 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. The system is designed to allow the
transfer of wastes to be traced from cradle-to-grave.
The Regulation
prescribes the storage facilities to be provided on site including labelling
and warning signs. To minimise the
risks of pollution and danger to human health or life, the waste producer is
required to prepare and make available written procedures to be observed in the
case of emergencies due to spillage, leakage or accidents arising from the
storage of chemical wastes. He/she
must also provide employees with training in such procedures.
The inert portion of construction waste ([1])
(also called public fill) may
be taken to public fill reception facilities. Public fill reception facilities are
operated by the Civil Engineering and Development Department (CEDD). The Land
(Miscellaneous Provisions) Ordinance requires that individuals or companies
who deliver public fill to the public fill reception facilities obtain Dumping
Licences. The licences are issued
by the CEDD under delegated authority from the Director of Lands.
Individual licences and windscreen
stickers are issued for each vehicle involved. Under the licence conditions, public
fill reception facilities will only accept inert earth, soil, sand, rock,
boulder, rubble, brick, tile, concrete, asphalt, masonry or used bentonite. In
addition, in accordance with paragraph 11 of ETWB-TC (Works) No. 31/2004,
Public Fill Committee will advise on the acceptance criteria (eg no mixing of construction waste, norminal
size of the materials less than 250mm, etc. The material should, however, be free
from marine mud, household refuse, plastic, metal, industrial and chemical
wastes, animal and vegetable matter and any other materials considered
unsuitable by the public fill reception facility.
This Regulation provides further control on
the illegal dumping of wastes on unauthorised (unlicensed) sites. The illegal dumping of wastes can lead
to a fine and/or imprisonment.
Other
'guideline' documents, which detail how the project proponent or contractor
should comply with the local regulations, are as follows:
·
Waste Disposal Plan for Hong Kong (December 1989), Planning, Environment
and Lands Branch Government Secretariat,
·
Environmental Guidelines for Planning In
Hong Kong (1990), Hong
Kong Planning Standards and Guidelines, Hong Kong Government;
·
New Disposal Arrangements for Construction
Waste (1992), EPD &
CED,
·
Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes (1992), EPD,
·
Works Branch Technical Circular (WBTC) No.
32/92, The Use of Tropical Hard Wood on Construction Site; Works Branch,
·
WBTC No. 2/93, Public Dumps. Works Branch,
·
WBTC No. 2/93B, Public Filling Facilities, Works Branch,
·
Waste Reduction Framework Plan, 1998 to
2007, Planning,
Environment and Lands Bureau, Government Secretariat, 5 November 1998;
·
WBTC Nos. 25/99, 25/99A and
25/99C, Incorporation of Information on Construction and Demolition Material
Management in Public Works Sub-committee Papers; Works Bureau,
·
WBTC No. 12/2000, Fill Management; Works Bureau,
·
ETWBTC No. 33/2002, Management of
Construction and Demolition Material Including Rock; Environment,
Transport and Works Bureau,
·
ETWBTC No. 31/2004, Trip Ticket System for
Disposal of Construction & Demolition Materials, Environment, Transport and Works Bureau, Hong Kong
SAR Government; and
·
Environment,
Transport and Works Bureau (ETWB) Technical Circular (Works) No. 19/2005, Environmental Management on Construction
Sites, Hong Kong SAR.
During the construction phase, the main
activities, which will potentially result in the generation of waste, include
site clearance, site formation, demolition of
infrastructure at the existing SENT Landfill and construction of new
infrastructure. The typical waste
types associated with these activities include:
·
excavated
material;
·
construction
waste;
·
chemical
waste;
·
sewage;
and
·
general refuse.
The Extension Site is currently occupied
by CEDD’s fill bank operation in TKO Area 137 and the
existing infrastructure area of the SENT Landfill. It is anticipated that CEDD’s contractor will be responsible for removal of the
fill material, which is currently being piled up to about 15 mPD, before handing over the site to EPD. The existing infrastructure of the SENT
Landfill will be demolished after the new infrastructure at the Extension has
been constructed and commissioned.
The Extension Site will also occupy approximately 5 ha of natural hill
slope and require the construction of two 2,000mm diameter drainage tunnels
underneath the hill next to TKO Area 137.
To form the slope suitable for use by the Extension, blasting will be
required.
The quantity of
excavated material to be generated during the 2-year construction period is
around 1.1 Mm3 (approximately 0.8 Mm3 is soil and 0.3 Mm3
is rock), mainly from the slope formation work.
Approximately
563,000 m3 of the excavated materials generated from the slope works
will be reused on-site for formation of the landfill base and the leachate drainage layer. The excavated rock will be reused as leachate drainage stone and fill material after crushing at
the on-site stone crushing plant.
It is estimated that a surplus of 527,000 m3 of excavated
material (including soil and rock) will be generated during the construction
period. The total fill requirement
during the construction phase can be met by reuse of excavated material. Import of fill material is not required
during the construction phase.
Fill material will be required for the
operation/restoration phase of the Extension for daily, intermediate and final
covers and engineering works. The
estimated volume of fill material required is shown in Table 7.3a.
Table 7.3a Cut
& Fill Requirement by the Extension
|
Phases |
Volume of Excavated Material Generated (Mm3) |
Volume of Fill Material Required (Mm3) a |
|
Construction |
1.1 |
0.6 |
|
Phase 1 |
- |
0.4 |
|
Phase 2 |
- |
0.5 |
|
Phase 3 |
- |
0.5 |
|
Phase 4 |
- |
0.6 |
|
Phase 5 |
- |
0.7 |
|
Phase 6 |
- |
0.7 |
|
Total |
1.1 |
4.0 |
|
Note: (a)
During the construction period, the excavated
material will be used for site formation and construction of leachate collection layer. For Phases 1 to 6, the fill material
will be required for landfill cover and miscellaneous engineering works. |
||
It can be seen from Table 7.3a that the overall quantity of
fill material required is in excess of the quantity of excavated material generated. Ideally, all excavated materials will be
reused on-site for site formation, engineering works, lining, and
daily/intermediate/final cover.
However, in view of the relatively small size of the Site and the
construction and operation sequence, it would be difficult to stockpile all the
surplus material within the site boundary as frequent relocation of the
stockpile would be required in order to carry out site formation work. Due to the shape and size of the Extension Site, it
is necessary to form and line the entire base of the landfill prior to
commencement of waste placement.
Frequent relocation of the stockpile material on top of the liner and
drainage layer in the first year (Phase 1) of landfill operation may damage the
liner.
Given the Site
constraints discussed above, approximately 10,000 m3 of excavated
material will be stored on site during the construction period and the initial
period of Phase 1. The surplus
517,000 m3 of excavated materials will be transported off-site to
other construction sites for reuse.
As a last resort, the surplus material will be disposed of at the
planned Construction and Demolition (C&D) Material Handling Facility at TKO
Area 137 or the Anderson Road Quarry, subject to agreement with the quarry
operator and permission from the Mines Division of CEDD. As shown in Table 7.3a, import of fill material will be required throughout the
operation of the Extension. Similar
to the practice at the existing SENT Landfill, fill material can be obtained
from local construction industries.
Another option is to obtain fill material from the C&D Material
Handling Facilities and quarries, subject to review and the prevailing
operational condition at these facilities.
Approximately 1,500 tonnes of non-inert
waste (comprising mainly vegetation) which generated from the site clearance
works will be disposed of at the SENT Landfill.
C&D material (consisting of concrete,
brick, wood, packing materials, plastics, metal, steel and general refuse) will
be generated from the demolition of existing structures at the infrastructure
area of SENT Landfill and the construction of new buildings in the
infrastructure area of the Extension.
The main structures including its gross floor area (GFA) to be
demolished and constructed during the construction phase are summarised in Table 7.3b.
Table 7.3b GFA
of Major Buildings to be Demolished and Constructed
|
Demolished / Constructed Buildings |
GFA (m2) |
|
Buildings to be demolished at the existing
infrastructure area of SENT Landfill |
|
|
Offices
and Laboratory |
1,361 |
|
Gasoline
Equipment Room |
112 |
|
|
973 |
|
|
422 |
|
|
1,242 |
|
Total |
4,110 |
|
Buildings to be constructed at the new
infrastructure area of the Extension |
|
|
Offices
and Laboratory |
2,820 |
|
|
1,020 |
|
|
420 |
|
Maintenance
Workshop |
1,980 |
|
Total |
6,240 |
Based on the
generation rate of 0.7 m3 per m2 of GFA demolished ([2]), it is estimated that a total of about 2,877 m3
of construction waste will be generated from the demolition work at the
existing SENT Landfill. Based on
the generation rate of 0.1 m3 per m2 of GFA constructed ([3]), it is estimated that a total of about 624 m3
of construction waste will be generated from the construction of new buildings
at the Extension. The construction
waste will be sorted on-site into an inert portion (also referred to as public
fill, about 2,800 m3) and a non-inert portion (referred to as
construction waste, about 700 m3) ([4]) in order to reduce the amount of
construction waste to be disposed of at SENT Landfill. The public fill will be reused on-site
as fill material and miscellaneous engineering works while the 700m3
of construction waste will be disposed of at the SENT Landfill.
The construction waste will be transported
to the SENT Landfill via an internal road linking the two landfills. With the proper implementation of good
construction site practice, the handling and transportation of construction
waste to the SENT Landfill will not cause adverse dust, noise or water quality
impacts.
Chemical waste, as defined under the Waste Disposal (Chemical Waste) (General)
Regulation, includes any unwanted substances specified under Schedule 1 of the Regulation. Substances
likely to be generated from the construction of the Extension will include:
·
Used
paint, engine oils, hydraulic fluids and waste fuel;
·
Spent
mineral oils/cleaning fluids from mechanical machinery; and
·
Spent
solvents/solutions from equipment cleaning activities.
Chemical wastes may pose environmental,
health and safety hazards if not stored and disposed of in an appropriate
manner as outlined in the Waste Disposal
(Chemical Waste) (General) Regulation and the Code of Practice on the Packaging, Labelling and Storage of Chemical
Wastes. These hazards may
include:
·
Toxic
effects to workers;
·
Adverse
effects on air, water and land from spills; and
·
Fire
hazards.
The amount of chemical waste that will
arise from the construction activities will be highly dependent on the
Contractor’s on-site maintenance activities and the quantity of plant and
equipment utilised. With respect to
the scale of the construction activities, it is anticipated that the quantity
of chemical waste to be generated will be small (less than a hundred litres per
month during the construction phase).
With the incorporation of suitable
arrangements for the storage, handling, transportation and disposal of chemical
wastes under the requirements stated in the Waste
Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packaging, Labelling and Storage of Chemical
Wastes, no adverse environmental and health impacts, and hazards will
result from the handling, transportation and disposal of chemical waste arising
from the Extension.
Sewage will
arise from the construction workforce.
It is estimated that a maximum of about 170 workers will be working at
the site at any one time. With a
sewage generation rate of 0.15 m3 per worker per day, about 25.5 m3
of sewage will be generated per day.
An adequate number of portable toilets will be provided at the site to
ensure that sewage from site staff is properly collected. The portable toilets will be desludged and maintained regularly by a specialist
contractor. No adverse
environmental impacts are envisaged.
The presence of a construction site with
workers and associate site office will result in the generation of general
refuse (mainly consists of food waste, aluminium cans and waste paper) which
requires off-site disposal. The
storage of general refuse has the potential to give rise to adverse
environmental impacts. These
include odour if the waste is not collected frequently, windblown litter and
visual impact.
Assuming up to 170 construction workers
will be working on site at any one time, with a general refuse generation rate
of 0.65 kg per worker per day, the maximum amount of general refuse to be
generated will be about 110.5 kg per day.
Recyclable materials (ie
paper, plastic bottles and aluminium cans) will be separated for recycling, in
order to reduce the amount of general refuse to be disposed of at
landfill. Adequate number of
enclosed waste containers will be provided to avoid over-spillage of
waste.
The non-recyclable refuse will be placed
in bags and stored in enclosed containers, and disposed of on a daily basis to
the SENT Landfill. Given that the
quantity of general refuse to be disposed of at SENT Landfill is small, no
adverse impact on the operation of the landfill is anticipated.
With the implementation of the mitigation
measures recommended in Section 7.6.1,
no adverse environmental impacts caused by the storage, handling, transport and
disposal of general refuse are expected.
Landfill operation and restoration are not
waste generating activities. Waste
generated during the operational and restoration phases is mainly confined to:
·
sludge
from the LTP;
·
chemical
waste;
·
sewage;
and
·
general refuse.
Sludge will be
generated from the LTP. It is
estimated that at the maximum design flow rate during the 1st year
of the LTP operation, approximately 72.8 m3 of sludge (at 2% solids)
will be generated per day. It is
recommended to dewater the sludge to about 30% dry solids (about 4.9 m3 d-1)
prior to disposal at the SENT Landfill tipping face. The dewatered sludge will be transported
by truck to the tipping face.
Following the closure of the existing SENT Landfill, the volume of leachate will be reduced and the quantity of sludge
generated will be reduced to about 1.2 m3d-1. The sludge will be disposed of at the
Extension tipping face. It is not
expected that this small quantity of sludge will affect the landfill operation
or result in adverse environmental impacts.
The operation and restoration work will
involve the use of mechanical machinery.
Similar to the construction activities, the chemical waste likely to be
generated during the operation and restoration of the Extension may include:
·
Used
paint, engine oils, hydraulic fluids and waste fuel;
·
Spent
mineral oils/cleaning fluids from mechanical machinery; and
·
Spent
solvents/solutions from equipment cleaning activities.
The amount of chemical waste (mainly waste
lube oil from maintenance of plant and equipment) that will arise from the
operation and restoration activities will vary on monthly basis depending on
the maintenance schedule. With
reference to the existing SENT Landfill operation, it is anticipated that the
quantity of chemical waste to be generated during the operation/ restoration
phase will be small (on average less than a hundred litres per month).
With the incorporation of suitable
arrangements for the storage, handling, transportation and disposal of chemical
wastes in accordance with the requirements stated in the Waste Disposal (Chemical Waste) (General) Regulation and the Code of Practice on the Packaging, Labelling
and Storage of Chemical Wastes, no adverse environmental and health
impacts, and hazards will result from the handling, transportation and disposal
of chemical waste arising from the Extension.
It should be noted that the operations of
the existing strategic landfills have demonstrated that with proper management
of the chemical wastes generated on-site, there are no adverse environmental
impacts.
Sewage will arise from the operation
staff. It is estimated that a
maximum of about 150 staff will be working at the site at any one time. With a sewage generation rate of 0.15 m3
per person per day, about 22.5 m3 of sewage will be generated per
day. The sewage will be treated at
the LTP. No adverse environmental
impacts are envisaged.
General refuse will arise from the
operation staff and administrative activities. General refuse may consist of food
waste, plastic, aluminium can and waste paper. With a general refuse generation rate of
0.65 kg per person per day, the amount of general refuse to be generated will
be about 97.5 kg per day.
Recyclable materials (ie
paper, plastic bottles and aluminium cans) will be separated for recycling, in
order to reduce the amount of general refuse to be disposed of at the
landfill. Adequate number of
enclosed waste containers will be provided to avoid over-spillage of
waste. The non-recyclable refuse
will be placed in bags and disposed of at the tipping face on a daily
basis. With respect to the small
quantity of general refuse to be disposed of at the Extension, no adverse
impact on the operation of the Extension is anticipated.
During the aftercare phase, the main
activities at the Extension will be the continual operation of the landfill gas
and leachate management facilities and some minor
maintenance work, if necessary. A
small quantity of wastes will be generated during this phase
which mainly consist of:
·
sludge
from the LTP;
·
sewage;
and
·
general refuse.
Sludge will be
generated from the continual operation of the LTP during the aftercare
phase. Once the landfill is
restored, the leachate generation will be
significantly reduced and hence a decrease in the quantity of sludge. It is estimated that approximately 0.33
m3 of sludge (at 30% solids) will be generated per day. The dewatered sludge will be delivered
in enclosed containers to other waste disposal facilities, eg
other landfills or the sludge treatment facility for disposal. It is not expected that this small
quantity of sludge will affect the operation of other waste disposal facilities
or result in adverse environmental impacts.
Sewage will arise from the operation
staff. It is estimated that a
maximum of about 20 staff will be working at the site at any one time. With a sewage generation rate of 0.15 m3
per person per day, about 3 m3 of sewage will be generated per
day. The sewage will be treated at
the LTP. No adverse environmental
impacts are envisaged.
General refuse will arise from the
operation staff and administrative activities. General refuse may consist of food
waste, plastic, aluminium can and waste paper. With a general refuse generation rate of
0.65 kg per person per day, the amount of general refuse to be generated will
be about 13 kg per day.
Recyclable materials (ie
paper, plastic bottles and aluminium cans) will be separated for recycling, in
order to reduce the amount of general refuse to be disposed of at the
landfill. Adequate number of
enclosed waste containers will be provided to avoid over-spillage of
waste. The non-recyclable refuse
will be placed in bags and disposed of at other waste disposal facility eg other landfills or transfer station on a daily
basis. With respect to the small
quantity of general refuse to be disposed of at the waste disposal facility, no
adverse impact environmental impact is anticipated.
The assessment indicates that with the implementation
of the proposed waste management practices at the work sites, no adverse
environmental impacts are envisaged for the handling, collection and disposal
of waste arising from the construction of the Extension.
This section further describes the good
construction site practices to avoid or further reduce the potential
environmental impacts associated with the handling, collection and disposal of
construction and chemical wastes arising from the construction of the
Extension.
The Contractor must ensure that all the
necessary waste disposal permits or licences are obtained prior to the
commencement of the construction works.
The construction contractor will open a
billing account with the EPD in accordance with the Waste Disposal (Charges for Disposal of Construction Waste) Regulation. Every construction waste or public fill
load to be transferred to the Government waste disposal facilities such as
public fill reception facilities, sorting facilities, landfills will require a
valid “chit” which contains the information of the account holder to facilitate
waste transaction recording and billing to the waste producer. A trip-ticket system will also be
established in accordance with ETWB-TC
(Works) No.31/2004 to monitor the
disposal of construction waste at the SENT Landfill and to control
fly-tipping. The trip-ticket system
will be included as one of the contractual requirements and implemented by the
contractor.
A recording system (similar to summary
table as shown in Annex 5 and Annex 6 of Appendix G of ETWBTC No. 19/2005) for the amount of waste generated, recycled and
disposed of (including the disposal sites) will be established during the
construction phase.
Construction waste will be segregated
on-site into inert and non-inert materials and stored in different containers
or skips to facilitate reuse of the inert materials and proper disposal of the
non-inert construction waste.
Specific areas of the work site will be designated for such segregation
and storage if immediate use is not practicable.
The contractor will register as a chemical
waste producer with the EPD.
Chemical waste will be handled in accordance with the Code of Practice on the Packaging, Handling
and Storage of Chemical Wastes as follows.
Containers used for
storage of chemical wastes will:
·
Be
suitable for the substance they are holding, resistant to corrosion, maintained
in a good condition, and securely closed;
·
Have
a capacity of less than 450 L 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 Regulations.
The storage area for chemical wastes will:
·
Be
clearly labelled and used solely for the storage of chemical waste;
·
Be
enclosed on at least 3 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 of as chemical waste, if necessary); and
·
Be
arranged so that incompatible materials are appropriately separated.
Chemical waste will be disposed of:
·
Via a
licensed waste collector; and
·
To a
facility licensed to receive chemical waste, such as the Chemical Waste
Treatment Facility which also offers a chemical waste collection service and
can supply the necessary storage containers.
An adequate
number of portable toilets will be provided at the site to ensure that sewage
from site staff is properly collected.
The portable toilets will be desludged and
maintained regularly by a specialist contractor.
General
refuse will be stored in enclosed bins separately from construction and
chemical wastes. The general refuse
will be delivered to the SENT Landfill, separately from construction and
chemical wastes, on a daily basis to reduce odour, pest and litter impacts.
Recycling
bins will be provided at strategic locations to facilitate recovery of
aluminium can and waste paper from the Extension Site. Materials recovered will be sold for
recycling.
At
the commencement of the construction works, training will be provided to
workers on the concepts of site cleanliness and on appropriate waste management
procedures, including waste reduction, reuse and recycling.
The Contractor will ensure that all sludge
generated from the LTP will be transported to the tipping face in enclosed
containers. The small quantity of
sludge will be mixed with MSW and covered by construction waste immediately
after tipping.
Measures are similar to those outlined in Section 7.6.1.
All sewage from the operation staff will
be diverted to the LTP for treatment or the foul sewer if available.
General refuse will be stored in enclosed
bins and disposed of at the tipping area on a daily basis to reduce odour, pest
and litter impacts.
Recycling bins will be provided at
strategic locations to facilitate recovery of aluminium can and waste paper
from the Extension Site. Materials
recovered will be sold for recycling.
The Contractor will ensure that all
dewatered sludge (>30% dry solids) generated from the LTP be transported to
a waste disposal facility, eg other landfills or a
sludge treatment facility, for proper disposal on a daily basis.
All sewage from the aftercare staff will
be treated at the LTP or the foul sewer if available.
General refuse will be stored in enclosed
bins and disposed of at a waste disposal facility eg
other landfills or transfer stations on a daily basis to reduce odour, pest and
litter impacts.
Recycling bins will be provided at
strategic locations to facilitate recovery of aluminium can and waste paper
from the Extension Site. Materials
recovered will be sold for recycling.
No residual waste management impact is
envisaged during the construction, operation, restoration and aftercare of the
Extension.
It is recommended that weekly audits of
the waste management practices be carried out during the construction and
operation/restoration phases to determine if wastes are being managed in
accordance with the recommended good site practices. The audits will examine all aspects of
waste management including waste generation, storage, recycling, transport and
disposal. Audit of waste management
practices during the aftercare phase is not considered necessary given that the
amount of waste to be handled is small.
The key potential impacts during the
construction phase are related to wastes generated from site clearance, site
formation, demolition of the existing SENT Landfill infrastructure and
construction of new infrastructure.
It is estimated that approximately 1.1 Mm3
of excavated material (consisting of about 0.8 Mm3 of soil and 0.3
Mm3 of rock) will be generated, mainly from the slope formation
work. Approximately 563,000m3
of the excavated materials will be reused on-site for the site formation work
during the construction phase. A
further 10,000m3 of the excavated material will be stockpiled
on-site for reuse during the Phase 1 landfill operation. The remaining excavated materials
(517,000 m3) will be delivered to other construction sites for reuse
or the C&D Material Handling Facility and the Anderson Road Quarry, subject
to agreement with the quarry operator and permission from the Mines Division of
CEDD. Import of fill material will
be required throughout the operation of the Extension. These materials could be obtained from
the local construction industries, C&D Material Handling Facilities and the
quarry, subject to review and the prevailing operational condition at these
facilities.
It is estimated that approximately 2,800 m3
of inert construction waste (public fill) will be generated from the
construction and demolition of infrastructure. These materials will be reused on-site
for fill material and miscellaneous engineering works.
Approximately 1,500 tonnes of construction
waste will be generated from site clearance and 700 m3 of
construction waste will be generated from the construction and demolition of
infrastructure and will be disposed of at the SENT Landfill. Small amounts of chemical waste (less
than a hundred litres per month), sewage (about 25.5 m3 per day) and
general refuse (about 110.5 kg per day) will be generated during the
construction phase.
With the implementation of general good
construction site practices, the construction of the Extension will not cause
adverse waste management or environmental impacts.
It is estimated
that dewatered sludge (maximum at about 4.9 m3 per day at 30% dry
solids), chemical waste (less than a hundred litres per month), sewage (22.5 m3
per day) and general refuse (97.5 kg per day) will be generated during the
operation/restoration phase. With
good site practices, the potential environmental impacts associated with the
storage, handling, collection, transport and disposal of waste arising from the
operation and restoration of the Extension will meet the criteria specified in
the EIAO-TM and no adverse waste
management impacts are anticipated.
Small quantities
of dewatered sludge (about 0.33 m3 per day), sewage (3 m3
per day) and general refuse (13 kg per day) will be generated during the
aftercare of the Extension. While the
sewage will be treated in the LTP, the dewatered sludge and general refuse will
be disposed at other waste disposal facilities.
With good site practices, the potential
environmental impacts associated with the storage, handling, collection,
transport and disposal of the small quantity of waste arising from the
aftercare of the Extension will meet the criteria specified in the EIAO-TM and no adverse waste management
impacts are anticipated.