During the construction
phase, quantities of excavated materials and other wastes will be generated
which will require disposal in an appropriateLiquid and solid wastes
generated during construction will require to be disposed of in an
appropriately and environmentally acceptableacceptably manner.
This section of the EIA report involves ansummarises the
assessment of the potential environmental impacts fromcaused by the wastes
the generation of solid
and construction wastes from generated byduring the construction
of the proposed works and describesrecommends an appropriate disposal strategy. Thestrategy to alleviate the identified potential
impacts. The recommended disposal
strategy is based upon the waste management principle of reducingto reduce the
amount of waste requiring finalfor disposal
through the development of outline plans for waste avoidance, material re-use
and recycling.
Mitigation measures will be proposed to alleviate
the impacts caused by the ePotential
environmental impacts arising from the disposal of any eExcavated
materials and residual wastes may give arise to
impacts duringduring their handling, temporary stockpiling
or storage on site, transportation and final disposal. AThe key task therefore of thisthe waste
management assessment is to determine the types and where possible,and, where possible, estimate theing quantities of any alln solid
waste arisingss.
Moreover, in order to determinearising during the construction for determining
the
most appropriate methods of treatment,
handling and disposal, itdisposal. It will also be importantessential to In particular, determininge understand
the nature and composition
of the wastes, in
particular whether the waste materials
materials are eitherare
inert or contaminated
for allocating the appropriate disposal route, will ensure that waste materials are handled
correctly and will provide will ensure that waste materials are handled
correctly and will as a the basis for identifying suitable treatment or disposal options, and there by ensuring that waste materials are handled correctly.
Wastes including both the solid
and liquid wastes generated during the operational phase have
also been considered withinwill also be studied in this assessment. ImpactsThe findings obtained
from the impact assessment on water quality from the generation of wastewaters
andwaste
water and the proposed
mitigation measures are have been discussed separatelyas stated in
Section 4 (Water Quality)
will be taken into account for assessing the Quality).impact caused by the
groundwater inflow into the cable tunnel.
The liquid and solid waste management assessment has been carried out in accordance with the requirements of Clause 3.7.2 of the Environmental Impact Assessment (EIA) Study Brief and Annexes 7 and 15 of the Technical Memorandum on Environmental Impact Assessment Process (EIA-TM).
The overall objectives for the liquid and solid waste
management assessment are summarised below:to:
(i)
to assessidentify the
construction activities involved for the proposed works and
determine the type, nature and where possible, estimate the volumes of waste to
bedetermining
the types, nature and quantities of s waste generated;
(ii)
to identify
any potential environmental impacts from the generation of
waste associated with thecaused by the wastes generated from the proposed works;
(iii)
to categorise
waste materials where practical, i.e. suitability for re-use/recycling,
disposal to public filling areas, disposal to landfill and any pre-treatment
requirements (particularly
pre-treatment process of the slurry generated from drilling the cable tunnel) prior
to disposal;
(iv)
to recommendassess and evaluate
appropriate waste management options (including potential waste
minimisation on-site, re-use or recycling opportunities and off-site disposal routesoptions);
(v)
to identify siterecommend appropriate
management/mitigation measures that should be may need
to be implemented
to minimise any potential impacts fromthe identified impacts
during the generation, handling, storage;
(vi)
storage and disposal
measures/routings of waste,set up appropriate routes for waste disposal,
in accordance with the current legislative and administrative requirements; and
(i)
to assess handling and disposal
requirements of bentonite slurries in accordance with the Practice Note For
Professional Persons ProPECC PN 1/94.
(vii)
pre- treatment process of the slurry generated from
boring the cable tunnel and the disposal method; and
(i)
(viii)identify
the possible sites for dumping.
Wastes
which willare likely to be generated during the
construction phaseof the proposed works include the following:
(i)
vegetation and
demolition wasteVegetation and topsoil removed from site
clearance;
(i)
excavated materials from
earthworks (e.g. cuttings, regradingworks);
(i)
general construction waste (e.g. wood, scrap
metal,concrete);
(i)
chemical wastes generated by general site
practices (e.g. vehicle and plant maintenance/servicing);and
(i)
municipal wastes generated by siteworkers.
It is estimated that 25,000m3 of
disposal materials dominantly rock with less than 10% soil will be produced.
For a typical loader which can carry 5m3
disposal materials. The spoil can be removed off site within 4 months by land
access if vehicle rate is 50 vehicles per day. This will be in accordance with
EPD’s Technical Circular No 1-1-92, taking into consideration subsequent
revisions to the quality criteria in light of the proposed New Sediment Management
Framework.
(ii)
Excavated materials;
(iii)
Construction & demolition materials;
(iv)
Chemical waste;
(v)
Slurry generated from tunnel boring; and
(vi)
Municipal wastes.
During the ground
preparatory works, areas of tree and shrub cover will need to be cleared (refer
toSite
clearance will be required at the proposal tunnel portal locations in Pui O and
Tai Long Wan. Approximately 0.15ha of vegetation (mainly trees and shrubs
identified in Section 6, Ecology) and will require
disposal. An estimated 0.15area of
approximately 0.15 Ha of vegetation willtopsoil will need to be cleared and will require disposal.
Detailed
information on the density and eight of vegetation cover is not available at
this stage and total volumes to be generated have been broadly estimated only
[not expected to exceed X m3].
Topsoil will be segregated from roots and re-use
for the landscaping works for the portals to
·
waste timber formwork – approximately 500m2
or equivalent to 10m3 by volume;
·
spent concrete and cement screeding – very minimal,
assume 20m3 ;
·
waste reinforcement bars – very minimal, assume 3m3
waste material will be generated and collected for re-cycling; and
·
material and equipment wrappings, assume 30m3 .
The estimated total
volume of construction and demolition wastes to be generated is not expected to
exceed 60 m3, of which 20 m3 spent concrete and cement
screeding is classified as C&D materiel which can be disposed of as public
fill.
Excavated Materials
The
greatest volumes of excavated materialsThe greatest volume of
excavated material will arise from the excavation of the cable tunnel
and at the tunnel portals. Wherever
possible,trench, cable tunnel and the site formation at the
portals in Pui O and Tai Long Wan. The approach to be adopted for this material
is one of “zero off-site disposal” wherever possible. In this case, the
excavated material from the earthworks will be re-used on- site
as structural fill or for landscaping purposes. This will - thus maximiseing the utilisation use rate of
materials on site and reducing reduce the requirements for off sitewill be re-used on site
for backfilling or for disposal.
reviewed
to identify potential contaminating land uses.
The desktop study and was
supported by on site observations where possible. The review focused on areas where significant excavation would
take place, i.e. where cuttings are required.
Owing to the excavation of the cable tunnel and the tunnel portals,
generation of excavated materials isanticipated.
In the unlikely event that contaminated
materials are encountered, the appropriate measures as outlined under Section
9.4.1 should befollowed.
Construction
Waste Material
Construction waste likely to be generated
during the site formation works include thefollowing:
· waste wood from concrete formwork;
·spent
concrete;
· waste
steel rebars from concrete reinforcement activities; and
·ent
wrappings.
Submarine cables – the submarine cables will be laid by direct burying method. No excavated material is anticipated to be generated during the course of submarine cables laying works.
The project works
incorporates the construction of retaining walls, abutments and viaducts which
may have piled foundations whichthat. may require the use of The contractor may
utilise bentonite slurries. during pile construction and in It is common
accordance with common practice among
contractors, these are likely to be reuse re-usedthese slurries
during the construction period, thus reducing the
volume requiring final disposal.
The estimated total
volume of construction wasteand demolition wastes to be generated is not
expected to exceed 5000700 m3.Volumes
of bentonite slurries requiring final disposal will depend on site practices.
· solid wastes (empty fuel/lubricant drums, used oil/air filters, scrap batteries, vehicle parts); and
·
liquid wastes (used lubricants,
spent acid/alkali from batteries maintenance, waste oils/grease, gearbox
fluids, spent mineral oils/cleaning fluids, spent
solvents/detergents and possibly spent acid/alkali from batteries
maintenance produced from cleaning activities).
Slurry generated from tunnel boring
Chiller
will be used for cooling in the boring process to avoid excessive consumption
of water which leading to generation of slurry and adversely affect the water
quality of the water receiving bodies. Groundwater inflow into the tunnel
depends on various factors:-
·
the size of the water
source;
·
the head of water above
tunnel;
·
the horizontal separation between the water
source and the tunnel;
·
the recharge to the
water source;
·
the degree of joint
openness.
The
condition of water inflow into the cable tunnel has been investigated in the
tunnel preliminary design. The tunnel designers have stated in the Preliminary
Design Final Report, August 2001, that methods such as pre-injection will be
adopted to avoid excessive inflow of
groundwater during construction. The method involves drilling at the
faces to form probe holes for grout injection. With the implementation of the
pre-injection method, the amount of water inflow into the tunnel is considered
very minimal.
However,
as a preventive measure, in case of slurry generated from the boring operation
as a result of groundwater seepage, the slurry will be properly collected and
discharged into sedimentation tank and de-silting tanks for sedimentation and
filtration prior to discharge. As indicated in Section 4 if the sedimentation
tanks cannot treat waster water to the level required for discharge (as will be
stated in the discharge licence).
Site construction
workersWorkers will generate municipal wastes which
will besuch as predominantly comprisecomposed of food wastes, packaging andwaste
paper.
wastepaper. No
accurate figures are available on the likely volumes of to be generated
by site workers are available although EPD have predicted that on average,For
estimating the quantity of municipal wastes, EPD’s average value
1.07kg/employee/day of municipal waste may be expectedhas
been adopted (Monitoring of Municipal Solid Waste 1996, EPD (1997) Hong
Kong Government). The total volume of waste generated depends on the number of quantity
ofworkers to be employed on site and the anticipated maximum
number of workers and site staff to be employed at peak time
is 50 number. Considering 6 working
days per week, the amount of municipal waste generated will thus
be dependent on the number of sitebe 321 kg/week. Disposal
will be the responsibility of the Contractor who shall in accordance with
general avoidance of workers that the
contractor proposes to use. For
estimation purposes, we have assumed a maximum of 50 site staff. nuisances
measures (required under the Contract) remove material at such a frequency to
avoid nuisance.
Table 9-1 Estimated
Flow and Loads Caused by the Construction Workforce
|
Flow (m3/d) |
SS (kg/d) |
BOD
(kg/d) |
COD
(kg/d) |
TKN
(kg/d) |
NH3N
(kg/d) |
E.Coli
(no./d) |
|
3.0 |
1.7 |
1.7 |
3.5 |
0.335 |
0.2 |
1.75x1012 |
Apart from the very
minimal groundwater seepage in the cable tunnel for discharging into adjacent
water receiving water bodies. It is anticipated no other waste will be
generated from the operation of the Project.
Groundwater seepage during operation phase
Although the envisaged rate of water inflow into
the cable tunnel is low, drainage channels will be installed to discharge
groundwater by gravity systems to the main 200mm diameter drain located in the
tunnel invert. No water pumps will be required and provided inside the tunnel.
Since the groundwater is unlikely to be contaminated, it is anticipated no
adverse impacts will arise as a result of discharging this water to the water
receiving body (marine environment).
Broad estimates for the
volumes of generated waste have been assigned for each waste type although
total amounts will be determined by the contractor's working practices/site
procedures. Estimated volumes of
materials to be generated are presented with in Table 9-1.
The construction programme presented
inwill extend over a an approximate 3 year
period3 year period (March 2002 to February 2005), with site
clearance, earthworks and construction activities phased according to the
following construction sections of highway: 2005). The estimated types and volumes of waste
generated have been identified and are summarised in Table 9-2.
(i)Tunnel
section
(i)Submarine
section
(i)Underground
section
(i)Testing and Commissioning for the wholeroute
Table 9-1
Table
9-2 Summary of Wastes to be Generated
|
Activity |
Material Type |
Likely Time of Arising |
Estimated Total Volumes Generated |
|
Construction
Phase – Underground cables |
|||
|
Breaking up of hard
paving |
C&D
materials disposed of as public fill |
Laying of underground
cables |
1,100 m3 |
|
Trench excavation |
Soil |
Laying of underground |
Nil |
|
Construction
Phase – Cable Tunnel |
|||
|
Site clearance |
C&D
Waste – mainly trees and
shrubs |
Formation of tunnel
portals |
450 m3 for
a coverage area of 0.15ha |
|
Excavation |
Soil/Rock (100% surplus materials to be disposed of as public fill) |
Formation of tunnel
portals in Pui O and Tai Long Wan |
1,850 |
|
Excavation |
Rock (100% to be reused for other CLP’s projects) |
Tunnel
construction |
27,000 m3 |
|
Construction of ventilation building and tunnel portals |
C&D
materials disposed of as public
fill |
Construction of ventilation building and tunnel portals |
60 m3 |
|
Tunnel drilling and
groundwater seepage |
Slurry |
Tunnel construction |
Very minimal |
|
Construction
Phase – Miscellaneous |
|||
|
Servicing
of construction plants |
Chemical
waste |
Throughout
construction period |
450
litre/month |
|
Municipal
wastes |
Municipal
waste (general Refuse generated by site staff) |
Throughout
construction period |
321
kg/week |
|
Operational Phase |
|||
|
Seepage of groundwater |
Ground
water |
Throughout
the operation phase |
Very
minimal |
Waste materials have the potential to
cause adverse environmental impacts during generation, storage, transport and
disposal. The principal adverse effects relate to dust, visual impacts, water
quality, and
general health and safety and visual impacts. For each anticipated waste category, the potential environmental
impacts are highlighted and appropriate mitigation measures/disposal options
recommended below. These
recommendations form the basis of the Waste Management Plan (WMP).
Overall,
the project should aim to implementW waste
management procedures should be implemented to minimise potential
impacts to the environment. This may be
achieved by consideration and application of the following protocols :
(i)
avoiding and/or
minimisingavoid and/or minimise waste generation where
practical by improvements or changes in the project design or site procedures;wherever practical by
changing its quality or site procedures (e.g. convert excavated soil to topsoil
by mixing with compost, allow excavated material for backfilling in other
locations simultaneously);
(ii)
reusing/recycling/recovering
materialsmaximise the opportunity for
reusing/recycling/recoveringmaterials where possible
and thereby negating/minimisingnegate/minimise the
disposal requirements (e.g. by waste segregation according to type, separation
of recyclable materials such as metal, reuse of wood from site
hoarding/concrete formwork,maximise reuse of timber formwork wherever
possible, utilisation of excavated materials for
filling or landscaping); and
(iii)
ensuringensure that all
treatment and disposal options are comply with best practice and any
all
relevant guidelines and legislation.
The following specific measures should therefore be adopted during the detailed design and construction stages of the project to minimise waste generation:
Detailed Design :
·
Minimising excavation
requirements as far as possible.
·
Balancing cut and fill
requirements.
·
Evaluating the potentialEvaluate the
opportunities for maximising the re-use of excavated materials for
example, within landscape mounds.balancing the volume of
excavation and backfilling;
·
ConsideringIdentified possible
treatments for unsuitable excavated materials for re-use e.g. upgrading of subsoils
to top soilssubsoil to topsoil by mixing with compost.compost; and
·
Providing anAllocate area within
the construction site to allow
for sorting and segregation of materials.
Construction :
·
SSegregatingegregate waste
materials according to types to facilitate re-use and recycling.recycling;
·
Separation ofSeparate inert
construction and demolition materials for either re-use on-site or
use as public fill.dumping into public filling area or landfill site;
·
During demolition works,
segregatingSegregate different materials at source as
far as practical.practical;
·
CCo-ordinate
material deliveries to site in order to
minimise storage times on site and the likelihood of causing damage.to avoid damage and
producing waste material; and
·
Consider on site
mulching of vegetation to reduce bulk and review opportunities for possible use
within landscapingareas.
·
TrainingProvide training to
site staff in waste minimisation practices.
In accordance with good
practice, accurate site recordsA comprehensive site record should be
maintained throughout the construction works detailingperiod for easy tracking
of details on the quantities of materials; a) generated on site; b) reused on
site; and
c) disposed off site, together with disposal routes/locations. TheNo burning of
wastes on-site will not be permitted.materials on-site is
allowed.
Reference should be made to the WBTC No. 5/98 “On Site Sorting of Construction Waste on Demolition Sites”, WBTC No. 5/99 “Trip-ticket System for Disposal of Construction and Demolition Material” and WBTC No. 25/99 “Incorporation of Information on Construction and Demolition Material Management”. WBTC No. 5/98 refers to contracts which comprise solely demolition works although the measures proposed for mandatory on-site sorting of construction and demolition (C&D) material represents good site practice. The separation of inert C&D material (suitable for public filling) from C&D waste (considered unsuitable for use as public fill) is required to minimise the volumes requiring landfill disposal as far as practical.
WBTC No. 5/99 refers to the implementation of a trip ticket system for the proper disposal of C&D material to either public filling areas or landfills. WBTC No. 25/99 refers to the management of construction and demolition material (C&DM), i.e. inert material suitable for use as public fill or in earth filling projects.
Full reference should be made to the relevant WBTC for further details.
During the handling, storage, transportation and
disposal of site clearance wastes and excavated materials, potential adverse
effects may relate to dust, visual impacts, water and general health and safety.
safety.
All materials should be
re-used orexcavated materials other than for re-use should be
transported off site as soon as possible to minimise the potential for
adverse environmental impacts. It is
recognised that some stockpiling of materials will be required in some
instances although these should be segregated in terms of material type as far
as practical. to facilitate the potential for material re-use (e.gi.e. top soilfor
landscaping, suitable fill for engineering works).
All Transportation of
excavated material off
site should be handled in a manner that minimisesproper manner to
minimise the release of fugitive dust (especially during hot and dry
weather) and where possible the movement of material should
be kept to a minimum. Mitigation measures related to dust measures for thegenerated due to
handling of excavated materials on-site
have been addressed in detail within Section 3 (Air Quality). Within
the stockpile area,For stockpiling,
the following measures should be in place to control
potential impacts :theimplemented to mitigate against the likely adverse
impacts to the environment: generation of dust
and contaminated surface water run-off (i.e. high suspended solids) :
·
ecoveringxcavated material should be covered to
prevent washout and erosion during heavy rainfall;
·
ausingdopt dust
suppression techniques (such as dampening with fine water spray and covering
with tarpaulin);
·
acontrolling thevoid excessive use
of water during
spraying to prevent the
generation of runoff contaminated with elevated levels of suspended solids;
·
segregation of the
surface water system for the stockpile area and the fitting of silt traps where
appropriate;provide silt traps in the surface drainage system in
the stockpile area;
·
locatinglocate stockpiles
to minimise potential
visual impacts;
·
minimising land intake
of stockpile areas as far aspossible;
·
provide fencing withinfence up the
designated areas for
stockpiling to separate sensitive habitats and prevent stockpiling in unsuitableinappropriate locations; and
· designate appropriate haulage roads.
A reduction in the total volume of
excavated materials requiring off site
disposal will be achieved asoff-site can be achievedas far
as possible by optimising the re-use of suitable
material on-site.
BothFor the surplus eExcavated
material which cannot be re-used
on site and inert construction and demolition materials willwhich require
disposal to at public filling areas. Theareas, two possible locations have been identified.
These are the public filling area
at Tung Chung Development Phase 3A and the public fill stockpiling area at Mui Wo
have beenWo. Both were identified by the Secretary,
Public Filling Committee (PFC) as possibleavailable sites
duringlocations available for
dumping in accordance with the construction works programme.
Cleared vegetation derived from the ground
preparatory workssite clearance in the tunnel portals should
be segregated from any soil materials where practical and sent to a suitable
disposal site such as the WENT Landfill.
WENT Landfill will only accept restrictions specify
a a maximum of 30% by weight of inert
construction waste. It is
therefore important and procedures
on site should ensure only that soil / vegetation are kept
segregated. Mulching of vegetation on site would also reduce
the material bulk of material requiring disposal. Moreover, and where
possible possible opportunities for the possible beneficial use of the mulch
within landscaping areas either on site, or as part ofMoreover, the
opportunity for re-using the excavated topsoil for and landscaping proposed either on-site, or for other
landscaping projects, should be identified by the contractor prior
to selection of a landfill disposal
option.
In view of the inert nature of such material, its disposal is unlikely to cause long-term environmental concern. Stockpiling of all construction waste material prior to disposal should comply with the control measures outlined earlier in order to minimise any potential impacts related to dust, visual impact, water quality and general health and safety.
The excessive generation of inert
construction and demolition material increases disposal costs and may take up
valuable landfill space. With the Iimplementation
of good site management and careful , planning and
design considerations should be in place to reduce, the over-ordering of
materials and waste generation of inert
construction and demolition material should be minimised. In accordance with WBTC No. 19/99 (Metallic
Site Hoardings and Signboards), re-useable metal hoarding and signboards should
also be utilised on site to reduce the volumes of inert construction and
demolition material wood generated.
Where possible, inert construction and
demolition materials such as wood and metal should be separated out from other
materials for recycling. All recyclable
material should be clearly segregated and stored in appropriate skips/containers
or stockpiled. Segregation of material
will aid in the potential for re-use of material and in final disposal, if
necessary. Material recycling or re-use
reduces both the requirement
need for new construction materials and subsequent
together with overall collection,
transportation and disposal costs. Only when materials
cannot be reused should it they be
disposed of to a public filling area or, as a last resort, landfilled. All construction and demolition material
disposed at public filling sites must comply with the public dumping licensing
requirements (e.g. the material should be inert and contain <5% by volume of
timber). As far as possible, materials
should be sorted to minimise the requirement for off site disposal.
It will be the contractor's responsibility to ensure that inert construction and demolition material is collected by approved licensed waste collectors and that appropriate measures are taken to minimise adverse impacts such as dust generation. The contractor must also ensure that all necessary disposal permits are obtained.
Bentonite slurries should be reused as far as possible and final residues disposed of in accordance with the Practice Note For Professional Persons ProPECC PN 1/94. Slurries may either be disposed of at the marine disposal grounds (subject to obtaining a licence from EPD) or to the public drainage system following treatment to satisfy relevant effluent discharge standards (as set out in the WPCO Technical Memorandum on Effluent Standards).
Chemical waste, as defined in the Waste
Disposal (Chemical Waste) (General) Regulation, will require disposal
by appropriate and approved means. Potential hazards associated with disposal scheme to
eliminate the
potential
hazards as a result of inappropriate handling of these materials. The potential hazards include:
· effects on human health (i.e. dermal and toxic effects with respect to site workers);
· phytotoxic effects to vegetation;
· contamination of the soil, groundwaters and surface water following spillage;
· risk of fire or explosions; and
· discharge of chemical wastes to sewer and potential disruption of the sewage treatment works.
Chemical wastes should be stored in a locked, fully bunded area which is impermeable to both water and the waste being stored. The waste storage area should also be covered to prevent rainfall from accumulating within the bunded areas. The bunded area must have a volume of either 110% of the largest container or 20% by volume of the chemical waste stored in that area. Appropriate spill absorption material should be stored near the storage area in order to clean up any minor spill events. The risks associated with chemical waste storage and handling can be further minimised by :
·
designation ofdesignate an
appropriate, well ventilated storage area;
·
minimisation ofminimise waste
production and recycling/reprocessing for certain waste liquids where
appropriate (e.g. oils, solvents);
· careful handling of waste fuel and oil residues;
· use of appropriate and labelled (Chinese and English) storage containers;
·
locate storage of wastes remotearea away from
sensitive receivers (e.g. drains, residential properties and water bodies); and
·
education of workers on
the concepts ofprovide education to workers to enhance their
knowledge on site cleanliness and appropriate waste management
procedures.
An appropriate disposal facility is the Chemical Waste Treatment Centre (CWTC) at Tsing Yi. If chemical wastes are to be generated, the contractor will need to register with EPD as a chemical waste producer and observe the requirements for chemical waste storage, labelling, transportation and disposal. The contractor will also need to consider the guidance in "A Guide to Chemical Waste Control Scheme: A Guide to the Registration of Chemical Waste Producers" and the "Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes". All chemical wastes should be collected from site by a licensed chemical waste collector.
Material that is not acceptable at the
CWTC (e.gsuch as spent batteries) should be
sent to a co-disposal landfill such as the SENT Landfill.
If not appropriately managed, municipal wastes generated by site workers have a potential to cause impacts in terms of nuisance, insects and vermin. This may give rise to adverse environmental impacts for both site workers and site neighbours which could include:
·
odour nuisance if putrescible material
is not collected on a frequentregularly basis;
· wind-blown material causing litter problems;
·
propagate of vermin and pests inif the waste
storage area if it is
not well maintained and cleaned regularly; and
·
adverse visual impacts.visually unpleasant.
A temporary refuse collection facility should be set-up by the contractor and wastes should be stored in appropriate containers prior to collection and disposal. A private waste collection firm may be commissioned by the site contractor to remove the waste regularly (daily basis), to the satisfaction of the Engineer.
A summary of the proposed mitigation
measures and proposed disposal options are presented in Table 9-29-3 and form the Waste Management Plan
for the proposed project works.
Table 9-29-3 Waste
Management Plan
|
|
Control Measures |
Proposed
Disposal Method / Area |
|
General
Requirements |
Detailed Design Stage ·
maximising the opportunity for re-use of
excavated materials for example, forming the temporary working platform; ·
Provide treatments for converting unsuitable
excavated materials for use in other purpose e.g. upgrading of subsoil to
topsoil by mixing with compost; ·
providing an area within the construction site to
allow for sorting and segregation of materials. |
- |
|
|
Construction Stage ·
minimisation of waste generation for disposal
(via reduction/recycling/re-use); ·
segregating waste materials according to type to
facilitate re-use and recycling; ·
separation of inert construction and demolition
materials for either re-use on-site or use as public fill; ·
during demolition works, segregating materials at
source as far as practical; ·
co-ordinate material deliveries to site in order
to minimise storage times on site and the likelihood of causing damage; ·
training site staff in waste minimisation
practices; ·
transport of wastes off site as soon as possible; ·
maintain enance aof comprehensive accurate waste
records; ·
use of re-useable metal hoardings / signboards; ·
no on-site burning will be permitted; ·
follow the practice set out in WBTC No.5/99
“Trip-ticket System for Disposal of construction and Demolition Material”. |
|
|
Cleared
vegetation from site clearance |
·
segregationion
of materials to facilitate disposal; ·
segregation of excavated topsoil from roots and
re-use for the landscaping works to minimise the volume of waste requiring
off-site disposal. |
Re-use
/ landfill |
|
Demolition
waste |
·
segregation of materials to facilitate disposal; ·
appropriate stockpile management; ·
follow the practice set out in WBTC No.5/98 “On
site Sorting of Construction Waste on Demolition Sites”. |
Public
fill for inert wastes |
|
Excavated
materials |
·
segregation of materials to facilitate disposal /
reuse; ·
appropriate stockpile management; ·
re-use of excavated material on or off site
(where possible); ·
special handling and disposal procedures in the
event that contaminated materials are excavated; ·
follow the practice set out in WBTC No.5/99
“Trip-ticket System for Disposal of construction and Demolition Material”. |
Re-use
on site for suitable material.
Disposal to public fill areas for unsuitable materials. |
|
Construction
waste |
·
segregation of materials to facilitate
recycling/reuse (within designated area and in appropriate
containers/stockpiles); ·
appropriate stockpile management; ·
planning and design considerations to reduce over
ordering and waste generation; ·
recycling and re-use of materials where possible
(e.g. metal, wood from hoardings, formwork); ·
for material which cannot be re-used/recycled,
collection should be carried out by an approved waste contractor for landfill
disposal; ·
follow the practice set out in WBTC No.5/98 “On
site Sorting of Construction Waste on Demolition Sites”. |
Public
fill for inert wastes. Disposal to
landfill for materials unsuitable for public filling |
|
Chemical
waste |
·
storage within locked, covered and bunded area; ·
the storage area should not be located adjacent to sensitive receivers e.g. drains; ·
minimise waste production and recycle
oils/solvents where possible; ·
a spill response procedure should be in place and
absorption material available for minor spillages; ·
use appropriate and labelled containers; ·
educate site workers on site cleanliness/waste
management procedures; ·
if chemical wastes are to be generated, the
contractor must register with EPD as a chemical waste producer; ·
collection by a licensed chemical waste
collector. |
CWTC
or SENT |
|
Municipal
waste |
·
waste should be stored within a temporary refuse
collection facility, in appropriate containers prior to collection and
disposal; ·
regular, daily collections are required by an
approved waste collector; ·
provide sanitary facilities. |
- |
|
Operational
waste |
·
wastes should be stored within a designated
storage area; ·
waste such as material wrapping should be
segregated into recyclable, non recyclable and putrescible wastes, where
possible to facilitate disposal. |
Dependent
upon material type – refer to the waste categories above. |
The proposed cConstruction
activitiesworks associated with for the the proposed
works will generate a number of waste materials. These include:
· vegetation and demolition wastes from site clearance and paving breaking
· excavated materials
·
construction & demolition materials;
·
construction waste
· chemical waste
·
slurry generated from tunnel boring
· municipal waste
The potential impacts of wastes arising
from the construction phase of the installation of 132kV supply circuit project
have been assessed. Provided that the
mitigation measures outlined above are in place, potential impacts to the
environment associated with waste generated by the construction and operational
phases of the project will be controlled. Overall,With the recommended
procedures/measures in place, the construction and operational wastes generated/disposed alas part of this
project, will should
not lead to any significant adverse environmental impacts.
Further to this assessment, the waste management measures should be included in the contractors Environmental Pollution and Control Requirements as well as the Environmental Monitoring and Audit Manual.
The identified possible site for disposal
The
following sites were identified as possible locations for disposal of excavated
materials, construction and demolition waste & materials, chemical waste in
conjunction with the construction programme of the proposed works:-
(i)
The public filling area at Tung Chung Development
Phase 3A;
(ii)
The public fill stockpiling area at Mui Wo;
(iii)
The landfill site WENT in WWwest New Territories;
(iv)
Chemical Waste Treatment Centre (CWTC) at Tsing Yi;
(v) Material that is not acceptable at the CWTC (such as spent batteries) can be sent to a co-disposal landfill such as the SENT Landfill.